Pump Motors

Transcript

A.O. A .O. SMITH SM ITH A.O.Smith Motor Mastery University PUMP MOTORS APPLICATION INCLUDES: SWIMMING POOLS SPA & JETTED TUB MAINTENANCE INSTALLATION REPAIR TROUBLESHOOTING OTHER MODULES INCLUDE: HEATING, VENTILATION, AIR CONDITIONING & REFRIGERATION MOTORS GENERAL PURPOSE MOTORS SPECIAL PURPOSE MOTORS NOTICE: The information contained in this booklet is general in nature and is drawn from sources believed to be reliable. It is intended for general information purposes only. The descriptions in this booklet may not apply to a particular motor or a particular application. No warranties are intended to be created by this information. Contents Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 Motor Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 Nameplate Information . . . . . . . . . . . . . . . . . . . . . . . . . .4 Cross Referencing . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9 Installation Guidelines . . . . . . . . . . . . . . . . . . . . . . . . .11 eMod® . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15 Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20 Motors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20 eMod® . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22 Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26 Checklist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26 Test Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29 Electrical Checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31 Component Checks . . . . . . . . . . . . . . . . . . . . . . . . . . .33 eMod® Technical Support . . . . . . . . . . . . . . . . . . . . . . .37 Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45 Motor Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45 Impeller Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47 Bearing Replacement . . . . . . . . . . . . . . . . . . . . . . . . .48 Start Switch Installation and Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51 © 2006 A.O. Smith Corporation 1 Pump Motors Introduction Welcome to A.O. Smith’s line of Swimming Pool and Spa Pump motors. This manual is designed for one purpose – to make it simple for you to install, maintain, troubleshoot and service A.O. Smith pool and spa motors. All you need are a few basic tools and some helpful hints - the kind that appear throughout this booklet. We’ve included all the information we think you will need to solve the most common pump motor problems encountered out in the field. This easy to read manual contains great illustrations and diagrams for quick reference. Mastering the concepts in this manual will allow you to add the kind of value to your service that your customers will recognize and appreciate. WARNING! This is not a guide for the do-ityourselfer. These tips and suggestions are offered for persons with the proper qualifications and necessary test equipment. Replacements for every application. Every now and then you probably come across a motor that’s beyond repair. When you do, remember that A.O. Smith manufactures replacement pool and spa motors for practically every application you’ll ever encounter in the field. So save yourself some time and effort and just ask for A.O. Smith or A.O. Smith Century ® motors first – at any A.O. Smith distributor or dealer. A.O. Smith motors are as rugged as you will find, but keep in mind that all motors need service or maintenance at one time or another. A.O.Smith 2 Pump Motors Installation This section is divided into five parts. The first is Motor Types followed by Nameplate Information. The third is Cross-referencing followed by Installation Guidelines. The last is eMod® Installation. It is designed to help you select the correct motor for an application and install it properly. Motor Types There are five distinct electrical designs that are commonly found on swim pool and spa pumps. 1. Split Phase. This type of single-phase motor is used extensively in spa and jetted tubs and above ground pool applications. Some are used on pumps on the lower end of the in ground pool market. This design has a start winding and a start switch, but no capacitors. 2. Capacitor Start. This is a very common singlephase motor found on in ground pool pump applications. The starting torque is higher (150-175% of full load) and starting current lower than the split phase equivalent. The operation is similar to a split phase in that there is a start switch to take the start winding and capacitor out of the circuit once the motor reaches 2/3 to 3/4 of full speed. 3. Permanent Split Capacitor. This design does not have a start switch and is often referred to as a “switchless” motor. It uses a run capacitor that remains in the circuit at all times. The PSC design has significantly less starting torque than the capacitor start design. A.O.Smith Pump Motors 4. Capacitor Start/Capacitor Run. This design is used to increase efficiency in run mode. Both start and run capacitors are used. In run mode, PSC and Cap. Start/Cap. Run motors are the same. 5. Three phase (Polyphase). This is the simplest, most efficient design. Its use is limited to commercial and industrial applications because three phase power is not available in residential areas. 3 A.O.Smith 4 Nameplate Information Pump Motors When you need information about the motor you are replacing, you’ll always be able to find it printed on the motor nameplate. On A.O. Smith motors the nameplate is usually found on the side of the motor. Shown below are sample pool motor nameplates. As you read the nameplate, refer to the guide so that you can understand the meaning of each item that the manufacturer provides about its motor. Remember also that your dealer or distributor can help you choose the correct replacement motor. A.O.Smith Pump Motors 5 AMB: The maximum ambient (surrounding) temperature in which a motor is designed to operate. It is shown in degrees Celsius rather than Fahrenheit. Amps: Amps is the electrical current flowing through the conductors at rated load, rated voltage and rated frequency. Pool motors have service factor amps on the nameplate. This is amps at horsepower times service factor load and is the maximum acceptable current the motor should use. Catalog Number: (“CAT”). This number indicates that the motor is a stock rating, readily available from standard inventory as a replacement motor. Code: This is the NEMA code letter that specifies locked rotor kVA per HP (volts multiplied by locked rotor amps, divided by 1000 times rated HP). It is used to determine the correct size breaker needed in the electric box. ENCL (Enclosure): Enclosure refers to the openings or lack of openings in the shell and end frames. Motors are either open or enclosed. There are different categories within each. Pool motors are usually open “dripproof”. FR (Frame): The Frame identifies the mounting and shaft configuration. It does not indicate the diameter of the shell. Centurion and Centurion SE motors have a 6 1/2” diameter shell. Flex 48 and A.O. Smith two compartment motors have a 5 5/8” diameter shell. Either diameter can be 56C or 56J. That is because the shaft configuration and mounting holes are the same on both shell diameters. Square Flange motors, usually signified as 56Y or 48Y, mount the same regardless of the shell diameter. Square Flange motors are not recognized by NEMA, National Electrical Manufacturer’s Association, so there are A.O.Smith 6 Pump Motors no consistent frame size designations for them. However, Square Flange is an industry standard and all swim pool Square Flange motors mount the same. Note: A water systems manufacturer uses a square flange motor with a special shaft. Water system motors should never be used on swim pool applications. HP (Horsepower): Conventional unit of measurement for power (One horsepower equals 746 watts output). HZ: (Hertz): Measurement of frequency, equaling cycles per second of alternating current. The United States has 60 hertz current. Insul Class (Insulation Class): This is the temperature rating of insulation used in the construction of the motor. Most pool and spa motors use class “B” or class “F” insulation. Part or Mod Number: This identifies the motor’s specific design by part number. All motors have a model number. Only catalog motors have a catalog number. PH (Phase): Denotes whether the motor operates on single-phase AC current or three phase AC current. Rotation (Rot): Rotation is the direction the shaft turns. Almost all swim pool pump motors turn counterclockwise when looking at the motor from the end where the pump is located. This can be referred to as CCWPE. Impeller Rotation RPM (Revolutions per minute): RPM is how many times the shaft makes one complete revolution in one minute at rated horsepower, voltage and frequency. Serial: The serial code indicates the plant of manufacture and the date of manufacture. Each manufacturer is different. A.O. Smith has an explanation of the date code inside the front cover of the motor catalogs. A.O.Smith Pump Motors 7 SF (Service Factor): Service factor is a multiplier that when multiplied by the horsepower of the motor indicates the total permissible horsepower loading that may be carried when the motor is operating at rated voltage and frequency. TIP: The most important thing to remember when replacing a motor is that the replacement motor’s horsepower times its service factor must be equal to or greater than the original motor’s horsepower times it’s service factor. Time: Time indicates the duty cycle of the motor. Pool and spa motors are rated for continuous duty. Type: This is a code for the electrical design of the motor. For example, A. O. Smith uses “CX” to identify its PSC switchless design. Other codes are “CS” for capacitor start; “SP” for split phase and “UAK” for capacitor start/capacitor run. Be sure to check with your dealer or distributor, because each manufacturer’s type codes are different. Volts: Voltage is the required electrical potential applied to the motor. It is the force that moves the current in an electrical conductor. Single phase Pool and Spa motors will be 115, 230 or dual voltage, 115/230 volt. Dual voltage motors are usually connected for 230 volt at the factory because if 115 volts are applied incorrectly in the field the motor will just hum or run slowly, get hot and trip on the overload. This does not harm the motor. If the motor was connected for 115 volt at the factory and 230 volts were mistakenly applied the motor will burn out immediately. A.O.Smith 8 Pump Motors Motors are designed to run at plus or minus 10% of the nameplated voltage. A motor nameplated 230 volts will run from 207 to 253 volts. However, at 207 volts the motor amps will be slightly higher and the Rpm’s will be slightly lower. Some motors are rated 208-230 volts. These motors will operate in a range from 208 volts minus 10% to 230 volts plus 10% or 187 volts to 253 volts. TIP: Occasionally 200 or 208 volt motors are used. If a motor that has been designed for 200 volts or 208 volts is not readily available you can use a 230 volt motor with the next higher horsepower. For instance, a 1Hp 230 volt motor can replace a 3/4 HP 200 volt motor. TIP: There are no energy savings when connecting the motor to 230 volts versus 115 volts or vise versa. The advantage to the higher voltage is you can use smaller wire to connect the motor to the service and it reduces light flicker or dimming when the motor starts. Warning Labels: Make sure you read and understand all the warning information on the motor. Always TURN THE POWER OFF before working on a pool or spa motor. Wiring Diagram: On or near the nameplate is a schematic of how to connect the motor to the power source, change the voltage (if applicable), change the rotation (if applicable) or connect for different speeds (if applicable). When installing a replacement motor make sure the motor is connected for the same voltage as the power source. A.O.Smith 9 Pump Motors The nameplate of the motor being replaced contains much of the critical information needed to select a new motor. Some of the nameplate data detailed in the previous section is repeated below in order to reemphasize its importance when choosing a replacement motor Cross Referencing Choosing the right replacement motor is easy using these 5 steps: 1. Know the end frame you need. Is it: Thru Bolt 5.146 Bolt Circle Thru Bolt 5.812 Bolt Circle C-Face Keyed 56C Frame C-Face Threaded 56J Frame 2. Know the total horsepower output. Find the horsepower and service factor on the nameplate of the motor to be replaced. Multiply the horsepower times (x) the service factor. The result is the “total horsepower” of the motor. Do the same for the possible replacement motors. Select the replacement motor that has a total horsepower (horsepower times the service factor) that is equal to or greater than that of the original motor’s total horsepower 3. Is the original motor single or three phase? The original and replacement motors must be the same unless the power supply is being changed. Square Flange A.O.Smith 10 Pump Motors 4. What is the correct voltage? The operating voltage of the replacement motor must be capable of operating on the same voltage as the original motor. TIP: If the original motor was dual voltage (115/230 volt) and an equivalent dual voltage replacement is not readily available, a single voltage motor (115 volt motor or a 230 volt motor) of the actual voltage being used at the installation may be used. 5. What is the motor’s cycle or hertz? As a general rule, 50-cycle motors should not be substituted for 60-cycle motors and vice versa. Your distributor or dealer is also a great resource for determining what replacement motor you need. In addition motors can be cross-referenced on the A.O. Smith web site www.aosmithmotors.com. A.O.Smith 11 Pump Motors When replacing a motor that has failed, if possible, determine the cause of failure. If you know why the original motor failed you may be able to improve the installation so the new motor doesn’t fail for the same reason. Be particularly conscious of external conditions such as moisture, low voltage or dirt and debris that could have contributed to the failure. Here are more things you should consider when installing a motor: Installation Guidelines Heat The number one enemy of a motor is heat. Overheating always results whenever there is a lack of clean, continually circulating air through a motor. Heat can damage a motor’s windings, insulation, bearing lubricant and capacitors. In short, heat can quickly decrease the service life of a motor. Remember that proper ventilation is always a crucial consideration when installing a motor. If at all possible, install a motor in a location that is free of dirt, dust or airborne debris, such as leaves. Indoors is best, but not in areas with high humidity, such as a laundry room or shower area. If the motor is installed outdoors, try to choose a shady spot that’s protected from leaves and grass clippings. If you cover the motor to protect it from possible debris or water, there must be enough room between the cover and the motor to allow for a continual supply of unrecirculated outside air to flow through the motor. A.O. Smith single-phase pool and spa motors feature a thermal overload protector that will shut down the motor if it overheats. As the windings begin to cool down, the overload protector will automatically re-start the motor. Blocked ventilation or an overload condition can cause the motor to shutdown on a repeated basis. The motor is operating as it was designed. It is important to determine what is causing the motor to overheat and correct the problem. A.O.Smith 12 Pump Motors TIP: In situations where the ambient temperature is exceptionally hot, utilizing a high efficiency E-Plus or Conservationist motor in place of a standard efficient motor can prevent the overload protector from nuisance tripping. Moisture A.O. Smith motors have superior resistance to moisture, but you should avoid placing the motor where it can be splashed. Avoid installing the motor in low spots that could flood or under roof overhangs where gutters could overflow during heavy rains. Avoid locating the motor in the highest humidity area. It is best to elevate the motors at least two inches from the ground. Power source Before you turn the motor on, check to see that the line voltage, phase and frequency match the specifications shown on the motor nameplate. Current capacity must be adequate enough to maintain rated voltage at the motor terminals under all conditions. If it’s too high, contact your local utility. If it is too low check for overloaded circuits, loose connectors or wire of the wrong gauge (see wire selection guide). Altitude Generally, motors will run hotter with increasing altitudes. For installations more than 3,300 feet above sea level, it’s advisable to use a motor with the next larger horsepower rating than the one recommended for that application at sea level or use an E-Plus or Conservationist (high efficiency) motor of the same rating. Mounting Fastening the motor to the pump and the pump and motor assembly securely to a foundation or base, will prevent vibration, loosening and future misalignment. Make sure that the motor and pump assemblies rotate freely before starting the motor. A.O.Smith 13 Pump Motors Electrical connections The wiring diagrams shown on the motor make wiring your motor easy. Make sure the connections are tight to prevent failure or overheating. Grounding Always make sure the motor is properly grounded before applying power. In addition to the green grounding screw inside the motor, which grounds the motor to the service ground, every pool and spa motor has a bonding lug. The bonding lug is on the outside of the motor and is used to bond the motor and all other conductive surfaces together to prevent a potential difference between the surfaces. Grounding should be done in compliance with all local and national electrical codes. Wire Size Incorrect voltage at the motor terminals can cause the motor to overheat. It’s a good idea to check the electrical supply wires to confirm that the wire size is sufficient to carry the required voltage. For example, if you’re using a 1 HP motor at 115 volts over a distance of 150 feet use #8 wire. If the motor is being installed to operate on 230 volts, #10 Pump Motor Recommended Wire Size DISTANCE FROM SERVICE ENTRANCE/MAIN PANEL TO MOTOR Motor H.P.** 50 feet 115V 100 feet 150 feet 200 feet 230V 115V 230V 115V 230V 115V 230V 1/3 14 14 12 14 10 12 8 12 1/2 14 14 10 14 8 12 8 10 3/4 12 14 10 12 8 12 6 10 1 12 14 8 12 8 10 6 8 1-1/2 10 14 8 12 6 10 6 8 2 10 14 8 10 6 10 6 8 3 12 10 8 8 *Always follow all applicable codes. **Pump Motors with service factors greater than 1, and split phase designs. No more than 15 volts drop at start, in worst case. A.O.Smith 14 Pump Motors wire is sufficient for the 150 feet distance. Larger wire sizes reduce the voltage drop to the motor in both the start and run modes. A lower voltage drop means the motor will run more efficiently (cooler) and have increased service life. Pump Seal Always install a new seal when reassembling a pump or installing a replacement motor. A leaking pump seal may cause a motor to fail very quickly. To best protect the motor, A.O. Smith recommends the use of a Sintered Carbon Graphite Seal. It is important that the pump seal be installed correctly. The following are installation instructions provided courtesy of U. S. Seal Mfg. 1. Disassemble pump cavity to expose defective seal. Removal of old seal and assembly of new seal requires careful operations and precautions. Caution: Lapped and polished faces of new seal are easily scratched and damaged. PROTECT FROM DAMAGE, DIRT and FINGERPRINTS. 2. Carefully remove old seal head and seat taking care not to scratch shaft or seat counterbore. NOTE HOW THE OLD SEAL IS ASSEMBLED, TO BE SURE REPLACEMENT SEAL IS INSTALLED IN IDENTICAL MANNER. 3. Clean shaft and counterbore surfaces using fine emery cloth or equivalent. Remove rust, burrs and wipe clean. A.O.Smith 15 Pump Motors 4. Shaft, seat counterbore and rubber members of seal head and seat should be lubricated with a lubricant compatible with the seal elastomer. Check seals surfaces to be sure they are free of any dirt, grit or lubricants. 5. Press seal seat firmly into counterbore to be sure it is bottomed square. SLIDE SEAL HEAD ALONG SHAFT MAKING SURE THAT SPRING IS CORRECTLY ENGAGED INTO SEAL. 6. Re-assemble pump and remember that trouble free operation of a pump includes a correct seal installation. TIP: If the pump has been run dry long enough for the plastic pump to overheat, consider replacing the pump also. Overheating can cause the pump to warp making it impossible for the pump seal to prevent leaking. Additional Protection. Do not remove the water slinger (washer) from the shaft. It helps deflect water away from the motor bearing. Overview The eMod load sensing electronic module is an accessory to a pool pump motor. It is permanently attached to the motor and is used to protect the motor and pump from damage. eMod is SVRS compliant per ASME A112.19.17-2002 for suction lift applications. eMod® The load sensing module can turn the pool pump motor off if the input power to the motor is too low, indicating either a lack of fluid flow, or a dry running pump. It can also turn the motor off if the input power gets too high, indicating excessive load A.O.Smith 16 Pump Motors on the pump. The module can also shut the pump motor off if input current is too high, indicating a locked rotor or blocked pump impeller condition. eMod Set Up The eMod module is permanently mounted and wired to the motor. All necessary electrical connections are made at the factory. Basic Operation While the pool pump is running, the eMod module monitors pump motor input power. If the motor input power drops 10% below its normal running condition value for more than 1 second, the eMod will fault and the pump motor will be turned off. When faulted, the eMod module will flash the red LED on the end of the enclosure. If the motor input power increases more than 12% over its normal running condition value for more than 4 seconds, the eMod will fault and the motor will be turned off. If either of the out of normal conditions does not last for the required amount of time, however, the fault condition will not be latched, and the motor will continue to run. Startup Lockout Time Often times when starting a pool pump, there is air in the plumbing system. If the volume of air is large, it can take a minute or two to fully evacuate the air in the system and prime the pump. To keep the eMod module from detecting a low input power condition (lack of flow) a startup lockout period is employed. When the eMod is powered up, it will ignore the motor power input for up to 3 minutes before it starts to monitor the motor A.O.Smith Pump Motors 17 operating conditions. While the eMod module is in this startup lockout state, the green LED on the end of the enclosure will flash. If the pump primes faster than the 3 minute limit, the eMod circuitry will detect this and immediately go into running mode. When in run mode, the green LED on the end of the enclosure will be on. Calibration Because every pool is hydraulically different, the eMod module must be individually calibrated to each pool installation. The unit will automatically calibrate after running through the 3 minute priming period for the first time. When calibrating the unit, it is important to make sure that the pump is fully primed, and that all valves and filters are in their normal operating conditions. Also make sure that there are no leaves or other obstructions on the pool drains. This will result in the pump motor input power being at its normal operating value. During the three minute startup lockout time, the green and red LEDs will flash alternately. The alternate flashing LEDs indicates that the eMod unit is in auto-calibrate mode. At the end of the three minute priming period, the eMod will automatically calibrate and go into run mode (green LED on). If for some reason the pump is not yet fully primed, let the eMod unit fault out. Cycle input power and press the Reset button as discussed below. Note: It is important that the pump be fully primed and running at normal conditions when the eMod unit is calibrated. Note: For two speed motors, the eMod must be calibrated at both operating speeds. It is recommended that the eMod be calibrated at both speeds when the motor is initially installed on the pool, and the motor is still cool. A.O.Smith 18 Pump Motors Test of Proper Calibration Upon completing the installation of an eMod equipped motor to the pump and pool plumbing, and after calibration is complete, the manufacturer recommends that the unit be tested for proper function. This can be accomplished by either blocking the inlet of the drain or closing a main valve. The motor and the pump should shutdown in less than 10 seconds of this action. The red LED on the eMod unit should also be flashing. Remove the blockage or return the valve to the original position and the unit should begin functioning again in approximately two (2) minutes. It is recommended that this test be performed monthly to assure no changes have occurred in the calibration the pool system. If the eMod unit does not shutdown the motor and pump in less than 10 seconds, the unit should be Reset. Please refer to the Reset section of the installation guide. Once the unit is Reset, the unit will then calibrate to the new load point once power is applied to the unit. The blockage test should be repeated once the unit has completed the calibration and is operating with a solid green LED illuminated. Reset If for some reason it becomes necessary to reset the calibration of the eMod module (change in plumbing or other pool conditions), press the button next to the red LED on the end of the enclosure and hold it down for at least three seconds. Please note that this function is only active during the first three minutes of operation after the power is applied. This will erase the calibration memory and the motor will stop. Cycle power to the unit (wait 10 seconds with the power off to allow the internal power supply to reset). The unit will now go through a new auto-calibration period and then establish new values for motor input power and current, as was discussed in the calibration section above. A.O.Smith Pump Motors 19 Bypass Mode It may be necessary to defeat the eMod motor input power monitoring functions during unusual operating conditions in the pool. This might include hand wand vacuuming the pool, back flushing of filters or replacement of filters, or clearing a large volume of air from the pool plumbing system. To enter Bypass mode, press and hold the Bypass mode button for at least three seconds. The Bypass mode button is located next to the green LED on the end of the enclosure. The eMod will respond by starting to blink the red LED with the green LED on. Bypass mode will last for 30 minutes, or until the Bypass mode button is pushed for at least three seconds a second time. If at any time during the cleaning process the power is cycled off, the Bypass mode button must be pressed again once the power is cycled back on, otherwise the unit believes that cleaning has been completed and has returned to normal operation mode. If the unit stops during any cleaning activity, cycle the power off, wait 10 seconds, power on, and press the Bypass mode to continue cleaning operations. Caution: Bypass mode defeats the pump monitoring functions of the eMod. While in Bypass mode, there is no protection from a drain blockage suction condition or dry running pump. A.O.Smith 20 Pump Motors Maintenance As with a car or any other mechanical device, periodic maintenance is required to keep an A. O. Smith motor operating properly. While the motor itself does not often need attention, providing the proper environmental conditions around the motor can be the key to a long service life. Conditions change. It is important to monitor and correct any situation that might cause damage to the motor. Motors Moisture Water leaks from pump seals or pipe joints should be repaired to prevent failure of bearings and insulation. DO NOT splash or spray the motor. Mount the motor away from low spots and damp areas, and take measures to protect it from windblown rain. Cooling Provide for ample air circulation around motor. If an external motor cover is used, be certain it does not trap moisture and has enough space between the motor and the cover to allow fresh air to circulate through the motor. Clean the air inlets as required, making sure that the POWER IS OFF first. TIP: A running motor that is too hot to touch is not necessarily overloaded. Class B insulated motors have a maximum operating temperature of 130 degrees Centigrade (266 degrees Fahrenheit). If the automatic protector is not tripping and the actual running amps do not exceed the maximum amps on the nameplate, the motor is not overheating. Seasonal Whenever the motor must be shut down for extended periods, be sure all surfaces, vents and interiors are dry to prevent rust. If the motor is kept outdoors, cover it to prevent debris such as blowing leaves, dirt and snow from clogging the inlets. DO NOT SEAL THE MOTOR IN PLASTIC OR OTHER AIRTIGHT WRAPPINGS because condensation may form on the inside damaging bearings and insulation. A.O.Smith Pump Motors 21 TIP: When restarting the pump and motor after an extended down time, make sure the suction is flooded so the pump seal is wet. Starting the motor with a dry pump seal can damage the seal. Cleaning In general, the inside of the motor should not need cleaning if proper safeguards are made against contamination by dirt, lint or sand. If you want to clean the outside, simply use a damp cloth. Don’t spray the motor with a water hose. Flooding the motor can cause permanent damage. Lubrication The ball bearings in A.O. Smith motors are double sealed permanently lubricated. If it appears the bearings have failed, simply replace them. TIP: Noisy bearings are the first sign of bearing failure. If the bearings are not replaced promptly, the motor can overheat causing the windings to fail. Bearing noise is often a sign that the pump seal has been leaking. Always change the pump seal when you change the bearings. Chemicals Do not store or use chemicals close to the motor. Dirt Avoid sweeping or stirring dust near the motor while it is running. A.O.Smith 22 Pump Motors eMod ® Operating Fault If a fault occurs while the eMod is in the running mode, the motor will be turned off and the red LED will flash. After two minutes, the module will attempt to re-start the motor. After the three minute startup lockout, or if the circuit senses that the pump is primed, the unit will once again start monitoring motor input power. If conditions are still not normal, the unit will fault out again. The eMod will attempt to restart like this four times. After the fourth attempt, the module will go to lockup mode. In lockup mode the red LED will be on. The only way to get out of lockup mode is to cycle power to the motor. Faults that the eMod will attempt to recover from are: • Motor input power too low • Motor input power too high • Motor current too high • Motor temperature too high • Power line voltage too low • Circuit power supply fault • Momentary loss of power If the motor runs normally for at least nine minutes when the eMod returns to run mode, the fault counter will be reset back to zero. This means that it will now require five new faults to reach lockup mode again. A.O.Smith Pump Motors 23 Fault Mode If the eMod faults and goes immediately to a steady red LED condition, this means the fault that was detected was critical, and the eMod went to lockup mode. The only way to get out of lockup mode is to cycle power to the motor. The faults that are considered critical are: • Power line voltage too high • Ambient temperature too low • Microprocessor fault • Reset switch is stuck closed • Bypass mode switch is stuck closed The eMod performs a self check of its electronic circuits on startup. If upon application of power to the eMod, it immediately goes to the fault condition, it is likely faulting on a failure of one of these circuits. Allow 15 or 20 minutes for the circuitry and motor to cool down if excessive running temperature is suspected. If the fault will still not clear, the eMod system will need to be replaced. The self check faults include: • Circuit power supply fault • Ambient temperature too low • Microprocessor fault • Software fault • Line voltage sense circuitry not working • Motor current sense circuitry not working • Motor control relays stuck A.O.Smith 24 Pump Motors LED Indicator Map Green LED Red LED Operating Mode On Off Run Mode Flashing Off Priming Mode Off Flashing Non-Critical Fault (circuit will attempt restart) Off On Lockup Mode (cycle power to attempt restart) Alternate Flashing Alternate Flashing Calibration Mode Flashing Together Flashing Together Reset Mode On Flashing (cycle power to restart motor) Bypass Mode A.O.Smith 25 Pump Motors eMod Load Sensing Module Specifications Input Power Voltage 102 to 130 vac rms single phase (low voltage connected) 195 to 250 vac rms single phase (high voltage connected) Frequency 58 to 62 hertz ** Power Consumption 5 Watts maximum (eMOD only) Line Loss Ride Through 20 milliseconds minimum Environment Operating Temperature Range 14 to 122 °F (-10 to 50°C) Storage Temperature Range -15 to 150 °F (-25 to 65°C) Humidity 10 to 95% non-condensing Altitude 5000 feet maximum Shock / Vibration 1G maximum (any axis) Enclosure Length 5.4 inches Width 3.5 inches Depth 2.6 inches Weight 1 pound Other drip and splash proof Other UL / CSA Compliance tested to UL 60730-1A FCC compliance tested to CISPR11 Class B ASME A112-19.17 – 2002 SVRS Suction Lift Compliant **Note: 50 Hz operation will result in incorrect timing. The eMod is rated for only 60 Hz operation at the present time. A.O.Smith 26 Pump Motors Troubleshooting There is not a single listing of motor trouble shooting pro c e d u res to be followed in a given ord e r. The pro c e d u res will differ depending on the situation. As with anything dealing with electricity, personal safety is of prime concern. Before you even touch the motor, MAKE SURE THE POWER IS OFF. Always turn the power off at the electric service fuse or breaker box. To prevent electrical shock, use a meter to check for electrical shorts and be sure the motor is securely grounded and bonded in conformity with local codes. Do not work on electrical devices if water or moist conditions are present and cannot be avoided. If the motor is not operating pro p e r l y, refer to the following: Checklist Motor fails to start (makes no sound) • Check the obvious first. Are the power switch and timer on? • Check for blown fuse or circuit breaker. If fuses are used be sure fuses are the proper size or type. • WITH THE POWER OFF, check all connections on the terminal board. Verify they are correct by consulting the wiring diagram on the motor. Make sure all connections are tight including the ground wire. • Check the voltage at the terminal board after first turning the power back on. Be sure to TURN THE POWER BACK OFF after completing this step. Note: Voltage at motor terminals should be + or – 10% of the voltage on the nameplate. If the voltage is high, contact the local Power Company. If the voltage is low check the wire size of the power line from the electric box to the motor. A.O.Smith Pump Motors • Check for overloading from other appliances on the same circuit as the motor. • Inspect motor windings for continuity. • Protector tripped – wait until the motor cools down then restart – check protector for continuity 27 Motor starts but shuts down (thermal overload protection) • Check the voltage at motor terminal. If it is too high call the local Power Company. • Check amperage. If high, find out if the pump impeller was recently replaced (it could be sized i n c o r rectly). Remember, motor horsepower times the service factor = total horsepower. Total horsepower must be equal to or greater than the impeller rating. Check for overloads. Noisy Motor • Check motor coupling, brackets and other attached parts. Tighten loose nuts, bolts or set screws. • Turn shaft. If it is rough or tight, check bearings • Look for loose or binding parts inside the motor or the pump. • Pump cavitation Overheating (smoking or cycling) • Check the motor’s ventilation by looking for clogged air vents or openings. Clean away all dirt and leaves or other debris from around the motor. • Check internal cooling fan. Is it intact and operating pro p e r l y ? A.O.Smith 28 Pump Motors • Compare connections to wiring diagram. Make sure motor is connected correctly for applied voltage. • Low or high voltage. Voltage should be + or – 10% of nameplated voltage. If it is higher that +10% call the local power company. If lower than –10% of the nameplated voltage check wire size from the service fuse box or circuit bre a k e r. If the voltage is low from the service use a motor one increment higher in horsepower or an E-plus or Conservationist high eff iciency motor of the same horsepower and service factor. T I P: Electric demand on the power company varies. If the motor is nuisance tripping because of low voltage it may only trip during the part of the day when electrical usage is the highest. Do your voltage checks at that time of day. • High ambient temperatures. Pool motors are usually designed to operate in 50 degree C ambients (122 degrees Fahrenheit). Artificially high ambients can occur if a motor operates in a confined space and recirculates the same air or circulates air from another motor next to it. • Check amp draw. If the amps are higher than nameplate amps but the voltage is acceptable, WITH THE POWER OFF, inspect the motor and the pump for mechanical obstructions that could cause an overload. • Look at motor windings and capacitors for damage or signs of shorting. Check for continuity. • Application overload. In cases of flooded suction or positive pre s s u re on the inlet side of the pump, flow may be increased overloading the pump. A.O.Smith Pump Motors • Misapplication. Make sure the motor is not undersized. Remember that total horsepower is horsepower times service factor. The total horsepower must be equal to or greater than the pump/impeller rating. • Check the motor start switch and governor (if applicable) to make sure it is adjusted properly and is operational. This section explains how to use test equipment. Conventional Multimeter or Ohmmeter 29 Test Equipment An ohmmeter can be used to measure the resistance of the various motor windings as well as to test the insulation. The ohmmeter will have numerous ranges from R x 1 where the meter reads directly in ohms, to a Rx100K where the actual meter reading must be multiplied by 100,000 for the actual ohm value. Before using an ohmmeter: • Make sure the power is off. • Read the instruction manual for the meter. • All troubleshooting checks specify the ohmmeter range to be used. If your meter does not have the exact range, use the next higher range. A.O.Smith 30 Pump Motors Digital Ohmmeter/Multimeter Direct reading digital ohmmeters are readily available in the field. To use this type: • Make sure the power is off. • Read instruction manual for the meter. • You do not have to set the ohmmeter to a particular scale as the meter displays the ohm value up to maximum capability of the meter. • Install probes and take resistance readings in the normal manner. Ammeter and Voltmeter Voltmeter Readings: Install leads in bottom of ammeter. Select the desired voltage scale. Take readings by touching one probe to each of the lead line terminals. Ammeter Readings: • Arrange leads so the jaws of the ammeter will encircle one lead. • Set meter on maximum amp scale and encircle jaws around one lead and take reading. It may be necessary to reset to a lower scale. A.O.Smith 31 Pump Motors Voltage Check • Make sure power is off. • Determine motor voltage and set meter • Reconnect power • Start the motor Electrical Checks Caution: All wires are live (hot) so use extensive care. Touch one probe to L1 and the other to L2. Voltage reading to be within 10% of nameplate voltage, i.e. between 207 and 253 volts for a motor nameplated 230 volts. If no voltage is recorded, check fuses, circuit breakers, timers, wiring, etc. for open connection or broken wires. If voltage is outside the acceptable limits, check for adequate wire size. Look for loose terminals and connections or pitted contacts. Check pump disconnect switch. Check voltage at service entrance. If not within plus or minus 10% contact power company. A.O.Smith 32 Pump Motors Amperage Check • Make sure power is off. • Set ammeter scale based on Max. Load amps. • Position one line lead (L1 or L2) so that the jaws of ammeter can encircle one power lead. (It will usually be necessary to install a test loop to have room for the meter jaws.) • Make sure switch and governor are free of obstructions (if applicable). • Reconnect power • Start the motor Caution: All wires are live (hot) so use extensive care. • Take a reading. The value should not exceed maximum load amps (service factor amps) on the motor nameplate. Excessive amps means an overloaded condition or incorrect voltage applied. Problem could also be a short in the motor. A.O.Smith 33 Pump Motors Perform the following checks to confirm that each component is functioning properly. Ground Check • Turn the power off. • Set ohmmeter to R x 1K. • Attach one probe to ground screw on the end frame and touch the other probe to all terminals on the terminal board, switch, capacitor and protector. A reading of less than 10K could indicate a ground. New motors typically read over one megohm. Old motors with dust, dirt and moisture could show resistance to ground below 10K and still run satisfactorily. A cleaning may be in order. Readings may vary from day to day depending on humidity levels. Approximately 25K at 115 volts will trip the ground fault device. Keep in mind the ground fault device is seeing the total leakage of all loads on the circuit. GFI’s normally trip on readings from 4 to 6 milliamps. • If grounded, check all external leads for cuts, breaks, frayed wires, etc. Replace damaged leads and recheck for grounds and proper lead routings, Make sure replaced leads are not pinched between canopy or cover and end frame. If ground is in the stator, the motor must be replaced. Component Checks Start Switch Check (if applicable) • Visual Checks 1. Make sure power is off. 2. Remove Canopy • Discharge capacitor by touching the two terminals simultaneously with the blade of an insulated handle screwdriver. A.O.Smith 34 Pump Motors • Make sure there are no obstructions preventing the proper operation of the rotating governor. Check wiring and make sure none of the leads are in the area of the governor where they can be cut or interfere with the governor. Check governor for proper operation and make sure flipper moves freely. • Check switch contacts for severely burned or pitted contacts, sticking etc. Some blackening or pitting is normal after the motor has been used. Replace switch if there is any doubt. DO NOT try to repair the switch by bending the contact blades. • The switch contacts in motors are plated and should never be sanded which would remove the plating and cause early failure. They may be cleaned by wiping the contacts with a piece of cardboard or paper bag. • Attach one lead to each terminal of the switch. Ohmmeter reading should be 0. With one lead on each terminal, flip governor weight to the run position. Reading should be infinity. • Reconnect power • Start the motor. Visually check the action of the switch and governor. Switch contacts must be closed when motor is at rest and should open when the motor reaches about 2/3 of full load speed. TIP: Replace the capacitor and switch at the same time. A defective switch usually stresses the start capacitor. Winding Continuity For typical two compartment, single phase, dual voltage only, capacitor start, single speed motor, connected for 230 volts. Set meter to R x 1. (For single voltage motors, check between L1 and L2.) A.O.Smith 35 Pump Motors Disconnect one of the red leads to the switch. Discharge capacitor by shorting across the terminals with the blade of an insulated handled screwdriver. Take the following ohm readings. L2 & A A & YELLOW Resistance between L2 and A must be the same as resistance between A and Yellow. YELLOW TO RED L2 TO RED Yellow to Red (winding side of switch) must be same as L2 to same Red terminal. A.O.Smith 36 Pump Motors Protector (Thermal Overload) Check • Set ohmmeter to R x 1. • Resistance between terminals: 1 & 2 should be approximately 0 (Disc.) 2 & 3 should be approximately 0 (Heater) • Replace if either value exceeds 1 ohm. TIP: Motor cycling on overload indicates some other problem not just a defective overload. Capacitor Check (Start or Run) • Set ohmmeter at Rx 1K. • Slip a heavy piece of paper between points on the switch. • Discharge capacitor by touching the two terminals simultaneously with the blade of an insulated handle screwdriver • Attach one probe to each terminal. Ohmmeter needle should move rapidly to right then slowly drift to the left. (Low ohm reading to high ohm reading.) • If digital meter is used, readings should start low and rapidly increase to maximum value. • Replace capacitor if bad. TIP: The replacement capacitor must be the same MFD as the original. However, if the same voltage rating is not available it is acceptable to use the next higher voltage. Example; if a 370 volt unit is not available, use the next rating, 440 volt. A.O.Smith 37 Pump Motors eMod® eMod Technical Support Questions and Answers Symptom: My eMod equipped motor nuisance trips (and has never run correctly). Possible Problem: The motor is configured for the wrong input power line voltage. Solution: Verify what the line voltage to the pool pump motor is with an AC voltage meter. If the line voltage is in the range of 110 and 120 volts, the motor should be configured for low voltage. If the line voltage is in the range of 208 to 240 volts, it should be configured for high voltage. Change the motor configuration with the voltage selector switch, or by moving wires on the motor terminal board as necessary. Possible Problem: The motor rotor or pump impeller is jammed. Solution: Remove power from the motor, and then remove the rear cover from the motor. Verify that the motor shaft turns freely by inserting a screwdriver into the slot on the end of the shaft, or by gently turning on the governor switch assembly with your hand. If the motor shaft does not turn freely, it will be necessary to separate the pump and the motor so that it can be determined which of the two is binding. If the motor is binding, it will need to be returned. If the pump is binding, verify that the pump parts were assembled correctly, and that all parts are in good condition. Possible Problem: Power line wiring is insufficient for the motor load. Solution: Measure the voltage on the motor terminal board with an AC voltage meter when power is applied and the motor is making the humming sound. If the voltage sags below 85 volts for 115 volt systems, or below 190 volts for 240 volt systems, there is too much resistance in the wiring to the motor to start reliably. A stronger electrical supply to the pump motor will need to be provided. Possible Problem: The eMod equipped motor is calibrated to the wrong motor load point. Solution: Follow the instructions in the Un-Calibrate section of this manual. A.O.Smith 38 Pump Motors Symptom: When I plug the hose to my suction cleaner in, the eMod equipped motor faults out. Possible Problem: Air in the cleaner hose is being drawn into the pump. This causes the pump to temporarily lose prime. The eMod detects this and shuts the pump off. Solution: Use the water flow from the return line to the pool to chase the air out of the suction cleaner hose before plugging it in. This will keep the pump from losing prime when you plug the hose in. Allow the eMod to go through its reset period of two minutes. It will then restart the pump and try for three minutes to re-establish pump prime. This is usually enough time to clear the air out of the lines and return to normal operating conditions. A.O.Smith 39 Pump Motors Symptom: My eMod equipped motor used to run fine, but now seems to fault a lot. Possible Problem: Skimmer basket, strainer basket, or main drain in pool is plugged with debris. Solution: Verify that the baskets and drains are clear and clean if necessary. Possible Problem: Filter needs to be cleaned. Solution: Check the pre s s u re gauge on the filter. If the pressure has gone up more than 5 PSI from where it was when the filter was clean, the water flow through the system may be reduced enough to cause the eMod to fault. Clean the filter if necessary. If the filter is a sand type filter, back-flush if necessary. Possible Problem: Not enough water in pool to cover the skimmer. Solution: Pump is drawing air into the system because the skimmer is not covered in water. The air causes the pump to partially lose prime and this causes the eMod to fault out. Add water to the pool if necessary. Possible Problem: Diverter valve(s) that choose return lines from pool to pump are in wrong position. Solution: Check to verify that diverter valve(s) are in the position that they were when the eMod was first installed and calibrated. Return valve(s) to the original position if necessary. If it is desired to operate the pool with a new valve position as the “new” normal position, please recalibrate the eMod. Instructions on how to do this are located in the Un-Calibrate section of this manual. A.O.Smith 40 Pump Motors Symptom: My two speed pump runs OK on high speed, but faults on low speed after running several hours. Possible Problem: Leak in plumbing system causes pump to lose prime. In high speed mode the pump moves enough water to absorb the air being leaked into the system. In low speed mode, however, the water flow is reduced to the point where the air bubbles accumulate in the strainer basket. Eventually the air bubble becomes large enough that the pump loses prime. Solution: Check to see that the strainer basket cover is tight, and the gasket is in good condition. Check the diverter valve(s) to make sure that it is in good condition and that the seals in it are in good condition. Check any unions in the piping system for proper fit up and that the O-ring seal is in good condition. Symptom: The eMod runs for less than one second when power is applied and then quits. Possible Problem: Failed relay on the eMod board. Each time the motor is powered up, the electronics checks the motor control relays to verify that they are working properly. If one of the relays is stuck shut, the motor will run for 1/2 to 1 second before the eMod electronics realizes that something is wrong and turns the motor off. Solution: The eMod equipped motor will need to be replaced. A.O.Smith 41 Pump Motors Symptom: My eMod equipped motor nuisance trips (and has never run correctly). Possible Problem: The eMod mis-calibrated when system was first set up. Solution: Sometimes the pump has a hard time clearing all the air from the pool return lines in the three minute window allowed by the eMod to do this. If this seems to be the case, follow the instructions in the Un-Calibrate section of this manual. Possible Problem: Air leak in the pool plumbing system. Solution: Check the water flow in the strainer basket of the pool pump. If there is a heavy flow of air bubbles in the water, or if the strainer basket never fills with water, there may be an air leak in the suction side plumbing to the pump. Check to see that the strainer basket cover is tight, and that the gasket is in good condition. Check the diverter valve(s) to make sure that it is in good condition and that the seals in it are in good condition. Check any unions in the piping system for proper fit up and that the O-ring seal is in good condition. Check for cracked pipes. Possible Problem: Pump/motor is too large for pool plumbing system. Solution: Check the water flow in the strainer basket of the pool pump for a heavy flow of air bubbles in the water. How does the pump sound? If it is making lots of noise, similar to the sound of a car tire on a gravel road, the pump is cavitating. There are both signs that the pump is trying to move more water than the pool plumbing is capable of delivering. Common causes of plumbing flow restrictions are long runs of small diameter pipe, too many elbows or valves, or the pump being located too high above the water level of the pool. If a change to the plumbing cannot be made to rectify the limit to water flow, the best solution would be to try a smaller pump/motor combination. A.O.Smith 42 Pump Motors Symptom: My eMod equipped motor nuisance trips (and has never run correctly). Possible Problem: Suction release valve of SVRS not adjusted correctly. Solution: If a mechanical type suction release valve is located upstream of the pump, it may be bleeding air into the system. Adjust the release setting on the valve to keep a tighter seal during normal running conditions. NOTE: If any adjustment is made to the SVRS device protecting a pool, its proper operation should be verified before allowing swimmers back in the pool. See the operator’s manual for the SVRS device in question for the proper procedure on how to do this. A.O.Smith Pump Motors 43 Symptom: When I apply power to my pump motor, the eMod immediately displays a solid red light. The motor doesn’t even attempt to start. Possible Problem: Voltage applied to the motor is out of the allowable operation range. Solution: Measure the voltage on the motor terminal board with an AC voltage meter when power is applied. If the voltage is not between 102 and 130 volts for 115 volt systems, or between 195 and 250 volts for 240 volt systems, the supply voltage is outside the allowable range for the motor. Check the voltage at other locations in the house to see if they are within normal limits. If other circuits are OK, inspect the wiring of the pool pump branch circuit. If all the house voltages are out of limits, contact the local power utility. Possible Problem: Temperature of the eMod electronics is too high or too low. The rated temperature of operation for the eMod and pump motor is from 14˚F (-10˚C) to 122˚F (50˚C). Solution: If the temperature is around 14˚F (-10˚C), the pump may be in danger of freezing up. If the pool water is heated and just the pump motor is cold, a method of keeping the eMod and motor at a more moderate temperature will need to be provided. A.O.Smith 44 Pump Motors Symptom: When I apply power to my pump motor, the eMod immediately displays a solid red light. The motor doesn’t even attempt to start. Possible Problem: Temperature of the eMod electronics is too high or too low. The rated temperature of operation for the eMod and pump motor is from 14˚F (-10˚C) to 122˚F (50˚C). Solution: If the temperature is around 120˚F (50˚C), wait until a cooler part of the day to see if the motor will now run again. If temperatures this hot are seen regularly, providing shade from the sun for the eMod and pump motor will give more reliable service. Also check to see that the cooling holes around the bottom of the motor are free of o b s t ructions and debris. Possible Problem: Internal fault in the electronics. Solution: If voltage temperature issues can be discarded, it is likely an internal fault in the eMod electronics that is causing the problem. The motor will need to be replaced. Symptom: When the power is applied to my eMod equipped motor, it runs for about 30 seconds and then stops. A solid red light is displayed. Possible Problem: The un-calibrate button or clean mode button is stuck. Solution: With the power to the motor off, try pushing the un-calibrate button and the clean mode button several times. Also wiggle the rubber actuator back and forth in the housing a little as occasionally the button gets hung up in the housing. Re-apply power to the motor to see if this clears the problem. If not, the motor will need to be replaced. A.O.Smith 45 Pump Motors Service A. O. Smith pool and spa motors are built tough, to run day after day without being serviced. When service is necessary serviceable parts can be accessed quite easily. Whether it is the A.O. Smith two compartment design with most serviceable parts in the “control room” under the rear canopy or the Century Centurion with externally mounted capacitor and “switchless” design, installing new parts is easy and quick. Motor Assembly All of the motors covered by this manual are similar in design and construction but may vary in type of protector, type of flange or electrical type. When disassembling, make sure you note the exact location of all components so they can be reassembled properly. This is especially true of the bearing assembly where the number of small parts (rings, washers, etc.) could easily be assembled incorrectly. Make sure you note the position of all the lead wires on the terminal board and where they are routed. CENTURION 56 FRAME SQUARE FLANGE POOL & SPA ASSEMBLY A.O.Smith 46 Pump Motors CENTURY FLEX-48 POOL & SPA ASSEMBLY TWO COMPARTMENT 56J FRAME POOL & SPA ASSEMBLY A.O.Smith Pump Motors 47 When ordering parts refer to the catalog number or model number and serial number on the motor nameplate. Impeller Removal All A.O.Smith motors have some method of locking the shaft so the impeller can be removed. Do not stick a screwdriver into the vent holes to prevent the cooling fan from turning to lock up the shaft. Some fans are plastic and will break. Two compartment designs have a flat on the shaft under the governor assembly. It can be accessed by carefully sliding a 7/16” open-end wrench under the protector at 12 O’clock until it drops over the flats on the shaft. Older Century Centurion models have flats on the rear end of the shaft. Access to the flatted portion of the shaft is achieved by removing a small metal cover on the rear end frame with a screwdriver. Current Century Centurion models have a plastic cover that can be removed by turning it 1/4 turn counterclockwise with a 15/16” wrench and pulling out. The end of the flatted shaft extends out from the rear of the motor. The shaft can be locked using a 1/2” wrench . Century Flex 48 motors have a screwdriver slot or a hex hole (that requires a 5/16” hex socket wrench) on the end of the shaft. A.O.Smith 48 Pump Motors Replacing a bearing in a motor is not a difficult task, provided you follow these set procedures. If a bearing is noisy or doesn’t run smoothly, it should be replaced. If a bearing is removed for any reason, it should be replaced with a new one. If it’s necessary to replace one bearing, replace the other as well to prevent return service calls and pump down time. Bearing Replacement Use only A.O. Smith bearings obtained from A.O. Smith and ordered by the proper A.O. Smith part number. Bearings obtained from A.O. Smith are built with balls having a specific fit, checked for sound level and filled with highgrade grease for the temperature and service conditions. A.O. Smith bearings are lubricated and require no further attention during their life. Do not substitute. Do not reuse old bearings pulled from shafts because this could damage the motor and cause a return service call. After the power has been shut off and the motor disassembled from the pump follow these steps: Note: Disassemble the pump in accordance with the pump manufacturer’s recommendations. 1. Mark the end frames and shell of the motor with two pieces of tape or a marker so the motor can be reassembled in the original configuration. A.O.Smith 49 Pump Motors 2. Remove the rotor and shaft from the shell by: (Century designs skip to 3.) For Two Compartment design, remove the canopy. Remove the switch to get access to the governor on the end of the shaft. Remove governor springs. Remove governor weight by spreading the bracket with a screwdriver. Take out screw on the end of the shaft and remove governor bracket. (See section on “Switch Adjustment” for instructions on how to set the switch when the motor is reassembled.) 3. Remove the four thru-bolts. 4. Remove the end frame opposite the shaft by putting a screwdriver in the notch and tapping the handle of the screwdriver. 5. Remove the shaft end frame, using the same method. Carefully pull the rotor and shaft assembly out of the shell from shaft extension end. Be careful not to lose the washer and bearing load spring that is positioned in the bearing bore in the end frame opposite the shaft extension. Be sure to replace the washer and spring during re-assembly. 6. Remove the bearing locking screws from the shaft end frame. Lock clip NOTE: New motors do not have a lock plate. They have a lock clip that is attached to the end frame with a single screw. The screw is located in one of the two holes that used to be used for the lock plate screw. Turn the screw 1/2 turn to release the bearing from the end frame. A.O.Smith 50 Pump Motors 7. Remove the shaft collars or snap rings used to secure the bearings. (You will need a pair of external ring pliers). 8. Use a bearing puller. (See“ Recommended Tools”) to remove defective bearing(s). 9. Install new bearing using a tube that presses only on the inner race of the bearing. (See “Bearing Information Table” for size of tube that is required.) Do not put pressure on the outer race of the bearing. The bearing will be damaged. Re-assemble in the reverse order of the disassembly instructions. If the motor is a Two Compartment design make sure you adjust the start switch correctly. (See pages 35-36). Make sure there are no leads in the area of the rotating governor. When the canopy is installed make sure no leads are pinched between the canopy and end bracket. Warning: Pinched wires or wires that come into contact with the rotating governor could cause a ground fault that is very dangerous should power be applied without the motor being properly grounded. For all designs, recheck wiring. Check rotor and shaft to make sure it turns freely by hand. Check motor for grounds before applying power. A.O.Smith 51 Pump Motors BEARING INFORMATION TABLE Bearing Dimensions Bearing Size Diameter (Inches) Inside Outside Width A.O. Smith Bearing Part No. (Inches) 203 .6693 1.5750 .470 604005-001 204 .7874 1.8504 .5512 100025-002 304 .7874 2.0472 .5906 603628-001 205 .9843 2.0472 .5906 603628-003 Bearing Installation Tube Dimensions (In Inches) Outer Diameter of Tube Wall Thickness Minimum Length 7/8 .095 3 1 .095 3 1-1/4 .125 3 RECOMMENDED TOOLS BEARING PULLER SNAP-ON TOOLS MODEL NO. CG-250 OR EQUAL TRU-ARC PLIERS EXTERNAL RING PLIER SNAP-ON TOOLS MODEL NO. PRS 22 OR EQUAL BEARING INSTALLATION TOOLS Single Speed • In November 2001, A.O. Smith began producing motors with a no-adjust switch. It is a one-piece design eliminating the need for the “U” bracket. The new switch needs no adjustment. Just assemble to the end frame. Make sure the plastic button is riding on the governor projection. • Older models use only one screw to secure and adjust the switch. Very old models have two screws. One to hold the switch in place and one for adjustment. Start Switch Installation and Adjustment • Fasten switch snugly to end frame, through “U” bracket with screw provided. A.O.Smith 52 • Pump Motors A slight amount of switch movement is possible before the screw (s) are tightened. Check to see that the switch button is centered over the governor projection. SWITCH ADJUSTING SCREW —TIGHTEN ONLY— PLASTIC BUTTON START SWITCH GOVERNOR PROJECTION GOVERNOR WEIGHT "U" BRACKET REMOVE AND OPEN "U" BRACKET SLIGHTLY TO INSURE SUFFICIENT SCREW TENSION WHEN INSTALLING NEW SWITCH OR AFTER SCREW HAS BEEN LOOSENED. .010” .040” MOTOR SHAFT • Reach in and move the governor weight (overcoming the spring tension) until it touches the stops on the governor. The clearance between the projection on the governor weight and the white button on the switch should be .010” to .040” (.040 is about the thickness of paper clip wire). • When installing a new or used switch, the “U” bracket should be opened slightly to insure sufficient tension against the screw. Tighten only when adjusting. If the screw is loosened, it should be removed and the “U” bracket should again be opened slightly. • Under no circumstances should switch contact blades be bent or deformed in an attempt to obtain proper contact clearance. 2 Speed Proper starting switch adjustment on two-speed motors is essential for satisfactory operation and contact life. • Disconnect all power to the motor before attempting any repair. Repair work should only be performed by a qualified electric motor technician. • Fasten switch snugly to end bell, through “U” bracket with switch mounting screw provided. • A slight amount of switch movement is possible before the screw(s) are tightened. Check to see that the switch button is centered over the governor projection. A.O.Smith 53 Pump Motors • Lift governor weight (overcoming spring tension) until it touches the stops on the governor. Clearance between the governor projection and the switch button should be .010” to .040 “. • Most newer models use only one screw to secure and adjust the switch. When a new switch is installed, or an existing switch is being reinstalled, the “U” bracket should be opened slightly to insure sufficient tension against the screw. Tighten only when adjusting. If the screw is loosened, it should be removed and the “U” bracket should again be opened slightly. • Under no circumstances should switch contact blades be bent or deformed in an attempt to obtain proper contact clearance. • Once the governor weight is released and the governor projection pushes on the switch button, contact “Z” should move away from the motor by approximately .030”. This movement assures that the points will have sufficient contact, no matter what position the rotor/shaft and governor projection are in at rest. • In run position contacts “X” and “Y” must be open and contact “Z” closed. At rest contacts “X” and ‘Y” must be closed and contact “Z” open. 2 SPEED SWITCH ADJUSTMENT .010 .040 SWITCH ADJUSTING SCREW —TIGHTEN ONLY TO OBTAIN PROPER CLEARANCE— CLEARANCE WHEN ACTUATOR IS IN RUN POSITION AS SHOWN SWITCH BUTTON START CONTACTS Y Z X SWITCH ASSEMBLY REMOVE AND OPEN "U" BRACKET SLIGHTLY TO INSURE SUFFICIENT SCREW TENSION WHEN INSTALLING NEW SWITCH OR AFTER SCREW HAS BEEN LOOSENED. SWITCH MOUNTING “U” BRACKET GOVERNOR ASSEMBLY SHOWN IN OPEN POSITION Other information valuable in servicing an Electric Motor can be found in the Trouble Shooting section. 531 NORTH FOURTH STREET TIPP CITY, OH 45371 937) 667-2431 FAX: (937) 667-5873 www.aosmithmotors.com © 2006 A.O. Smith Corporation Bulletin #3400 11/06 38 Pump Motors Centurion®/SE/II For motors manufactured in/after Nov., 1991 (Serial #BJ11) Dual Voltage Type CX-1⁄2 to 11⁄2 Hp 230/115 Volt Switchless HIGH VOLTAGE LOW VOLTAGE For motors manufactured in/after Nov., 1991 (Serial #BJ11) Single Voltage Type CX-11⁄2-5Hp 230 Volt Switchless EXTERNAL CONNECTIONS A.O.Smith 39 Pump Motors Centurion® For motors manufactured prior to Nov. 1991. (Serial #BJ11) Dual Voltage Type CX–1⁄2 to 11⁄2 Hp 115/230 Volt Switchless EXTERNAL CONNECTIONS Wiring Diagram #166359. Connection Label #166362. For motors manufactured prior to Nov. 1991. (Serial #BJ11) Single Voltage Type CX–2, 3 & 4 Hp 230 Volt Switchless EXTERNAL CONNECTIONS Wiring Diagram #166360. , 166361 Connection Label #166363. A.O.Smith 40 Pump Motors 1081 115/230 Volt INTERNAL WIRING Type CS–1⁄2 to 11⁄2 Hp Wishbone (Old Style) EXTERNAL CONNECTIONS Wiring Diagram #115242. Connection Label #115325. 115/230 Volt INTERNAL WIRING Type CP–2 Hp Wishbone (Old Style) EXTERNAL CONNECTIONS Wiring Diagram #139691. Connection Label #115325. A.O.Smith 41 Pump Motors 1081 230 Volt INTERNAL WIRING Type CP–3 Hp Wishbone (Old Style) EXTERNAL CONNECTIONS Wiring Diagram #153477. Connection Label #115317. 115/230 Volt Type CS–1⁄2 to 11⁄2 Hp Single Arm Switch (Old Style) LOW VOLTAGE HIGH VOLTAGE Wiring Diagram #157682. Connection Label #161035. A.O.Smith 42 Pump Motors 1081 115/230 Volt Type CP–2 Hp Single Arm Switch (Old Style) LOW VOLTAGE HIGH VOLTAGE Wiring Diagram #157683. Connection Label #161034. E-Plus® 230 Volt Type CX–2 and 3 Hp Switchless (Old Style) INTERNAL WIRING EXTERNAL CONNECTIONS Wiring Diagram #156228. A.O.Smith 43 Pump Motors 2 Speed 115 Volt INTERNAL WIRING Type CSM–1⁄2 to 3⁄4 Hp Wishbone (Old Style) EXTERNAL CONNECTIONS Wiring Diagram #157053. Connection Label #157187. Type CSM–1 and 11⁄2 Hp Wishbone (Old Style) 230 Volt INTERNAL WIRING EXTERNAL CONNECTIONS Wiring Diagram #157061. Connection Label #157187. A.O.Smith 44 Pump Motors 2 Speed 230 Volt INTERNAL WIRING Type CPM–2 Hp Wishbone (Old Style) EXTERNAL CONNECTIONS Wiring Diagram #157057. Connection Label #157187. Micro-Switch Motor (Formerly identified as Gould-Guard) 115/230 Volt Type CS–1⁄2 to 1 Hp (Old Style) LOW VOLTAGE HIGH VOLTAGE Wiring Diagram #157891. Connection Label #157892. A.O.Smith 45 Pump Motors Switchless Motor (Formerly identified as Gould-Guard) 230 Volt Type CX–11⁄2 HP Switchless (Old Style) HIGH VOLTAGE Wiring Diagram #157663. Connection Label #157664. (Formerly identified as Gould-Guard) 230 Volt Type CX–2 and 3 HP Switchless (Old Style) HIGH VOLTAGE Wiring Diagram #157669. Connection Label #157664. A.O.Smith 46 Pump Motors Centurion® Two-Speed Single Voltage 115 Volt Type CXPM–1⁄2 /.06 to 3⁄4 /.10 Hp Solid-State Switch EXTERNAL CONNECTIONS Wiring Diagram #167174. Connection Label #167200. Two-Speed Single Voltage 230 Volt Type CXPM–1/.12 to 2/.25 Hp Solid-State Switch EXTERNAL CONNECTIONS Wiring Diagram #167201. Connection Label #167200. A.O.Smith 47 Pump Motors E-Plus® Switchless Dual Voltage 115/230 Volt Type CX–3⁄4 to 11⁄2 Hp Switchless EXTERNAL CONNECTIONS Wiring Diagram #167985. Connection Label #166362. Single Voltage 230 Volt Type CX–2 and 3 Hp Switchless EXTERNAL CONNECTIONS Wiring Diagram #167976. Connection Label #166363. A.O.Smith 48 Pump Motors Flex 48® Frame Type SPM–3⁄4 /.10 HP Two Speed Single Voltage 115 Volt INTERNAL WIRING EXTERNAL CONNECTIONS Wiring Diagram #179679. Two-Speed Single Voltage 115 or 230 Volt Type CXSM 11⁄2 /.18 HP Type CXSM 2.0/.25 HP through 4.5/.50 Spl HP INTERNAL WIRING EXTERNAL CONNECTIONS Wiring Diagram #179859. A.O.Smith 49 Pump Motors Flex 48® Frame Two-Speed Single Voltage 115 or 230 Volt Type CSM 1.0/.12 Hp 115 Volt Type CSM 1.0/.16 Hp 115 Volt Type CSM 1.5/.18 Hp 230 Volt Type CSM 2.0/.25 Hp 230 Volt INTERNAL WIRING EXTERNAL CONNECTIONS Wiring Diagram #179277. Flex 48® Single Voltage 115 Volt WITHOUT AIR SWITCH Type SP–1⁄2 to 11⁄2 Hp WITH AIR SWITCH Wiring Diagram #179085. A.O.Smith 50 Pump Motors SINGLE SPEED MOTOR — TYPICAL SCHEMATIC DIAGRAMS Capacitor Start Induction Run — Single Speed EXT. & WIRE ROUTING Dual Voltage — Single Speed — Capacitor Start With Voltage Change Plug NOTE: When the voltage change plug is in the 115 volt position, the black lead is on the "L2" terminal and the black/white tracer is on the "A" terminal. When the voltage change plug is in the 230 volt position, the black lead is in the "A" terminal and the black/white tracer is isolated. A.O.Smith 51 Pump Motors Capacitor Start Capacitor Run — Single Speed SWITCH RUN. CAP. SINGLE SPEED MOTOR — TYPICAL SCHEMATIC DIAGRAMS Capacitor Start* or Split Phase Single Voltage on Winding Protector SWITCH *Capacitor not shown in schematic. A.O.Smith 52 Pump Motors SWITCH CONNECTIONS — HIGH SPEED START WHITE (COMMON) TOP VIEW START CAPACITOR LOW HI YELLOW TO #5 (FROM START WINDING) RED TRACER YELLOW TO #1 TO #5 RED TO #2 BLACK BLACK TO #3 TO #4 (4 POLE MAIN) YELLOW TO #1 (2 POLE MAIN) TERMINAL #1 TERMINAL #2 TERMINAL #5 TERMINAL #3 TERMINAL #4 END VIEW A.O.Smith 53 Pump Motors SWITCH CONNECTIONS — LOW SPEED START Low speed start — this design motor always starts on the low speed (4-pole) windings. When the control calls for high speed run, the start switch automatically switches the motor to high. WHITE (COMMON) TOP VIEW LOW ▼ HI ▼ YELLOW TO #4 BLACK TO #5 RED TRACER (FROM START WINDING) YELLOW TO #3 (2 POLE MAIN) BLACK #1 TO #5 RED TO #2 YELLOW TO #4 BLACK TO #1 (4 POLE MAIN) TERMINAL #2 TERMINAL #1 TERMINAL #5 TERMINAL #3 TERMINAL #4 END VIEW A.O.Smith 54 Pump Motors 2-SPEED MOTORS — HIGH SPEED START SCHEMATIC DIAGRAM 2-Speed for Remote Switch Operation WHITE LINE VOLTS (LOW SPEED) BLACK Z BLACK LINE VOLTS (HIGH SPEED) Y X START CAPACITOR RED YELLOW HI START - X & Y CLOSED Z OPEN RUN - X & Y OPEN Z CLOSED A.O.Smith 55 Pump Motors 2-SPEED MOTORS — HIGH SPEED START SCHEMATIC DIAGRAMS AND RECONNECTION INSTRUCTIONS FOR REMOTE OPERATION 2-Speed with Hi - Low Switch Mounted on Motor Canopy WHITE BLACK LINE VOLTS RED START CAPACITOR RED BLACK HI PURPLE LOW CANOPY SWITCH YELLOW YELLOW MUST BE CONNECTED TO BOTTOM TERMINAL WITH SWITCH IN POSITION SHOWN NOTE: START RUN - X & Y CLOSED Z OPEN - X & Y OPEN Z CLOSED Several different connections have been used in production. If the wiring on the motor you are reconnecting does not match these diagrams contact A.O. Smith and we will FAX or mail a connection for that model. RECONNECTION FOR REMOTE SWITCH OPERATION REMOVE BOTH YELLOW LEADS FROM ‘A’ TERMINAL AND CONNECT TO TERMINAL L1. REMOVE BLACK LEAD FROM HI-LOW SWITCH AND CONNECT IT TO TERMINAL A. LEAVE SWITCH IN CANOPY AND LEAVE PURPLE LEAD CONNECTED TO SWITCH. CONNECT POWER SUPPLY LINES TO TERMINAL BOARD L2-L1 HIGH SPEED L2-A LOW SPEED HI-LOW SWITCH PURPLE YELLOW BEFORE REPLACING MOTOR CANOPY, BE SURE ALL LEADS ARE PROPERLY PLACED TO PREVENT DAMAGE FROM GOVERNOR AND/OR CANOPY. A.O.Smith 56 Pump Motors 2-SPEED MOTORS — HIGH SPEED START SCHEMATIC DIAGRAMS AND RECONNECTION INSTRUCTIONS FOR REMOTE OPERATION 2-Speed with Hi - Low Switch Mounted in External Box BLACK START CAPACITOR YELLOW NOTE: Several different connections have been used in production. If the wiring on the motor you are reconnecting does not match these diagrams contact A.O. Smith and we will FAX or mail a connection for that model. RECONNECTION FOR REMOTE SWITCH OPERATION DISCONNECT PURPLE AND YELLOW LEADS FROM HI-LOW SWITCH AND CONNECT TOGETHER. DISCONNECT BLACK TRACER LEAD FROM HI-LOW SWITCH PERMANENTLY. TAPE UP EXPOSED END. L2 CONNECT POWER SUPPLY LINES TO TERMINAL BOARD L2-L1 HIGH SPEED L2-A LOW SPEED COMMON B SWITCH BOX BLACK TRACER A PURPLE L1 YELLOW A.O.Smith 531 NORTH FOURTH STREET TIPP CITY, OH 45371 937) 667-2431 FAX: (937) 667-5873 www.aosmithmotors.com © 2006 A.O. Smith Corporation Bulletin #3400 12/06