Transcript
5CIM2-0413 W30-AC0056
MODEL AC-SCC-5 INSTALLATION, OPERATION & MAINTENANCE MANUAL Multi-zone Hydronic Chiller Interface Module
SECTION 1: INTRODUCTION Unit description ............................................................................ Location ...................................................................................... Handling ...................................................................................... Mounting pad ..............................................................................
SECTION 3: OPERATION 5 5 5 5
SECTION 2: INSTALLATION Mounting ...................................................................................... Wiring ..........................................................................................
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Testing ......................................................................................... Control logic ................................................................................ Troubleshooting ........................................................................... Electrical diagram ........................................................................ Appendix A: Functionality ............................................................ Appendix B: Flow diagram ............ ..............................................
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IN UNITED STATES: 260 NORTH ELM ST. WESTFIELD, MA 01085 800-465-8558 / FAX (413) 564-5815 IN CANADA: 7555 TRANMERE DRIVE, MISSISSAUGA, ONTARIO, L5S 1L4 (905) 670-5888 / FAX (905) 670-5782
Model AC-SCC-5 Multi Zone Hydronic Chiller — Installation, Operation & Maintenance Manual
Section 1: INTRODUCTION The SpacePak AC-SCC-5 is an interface module that allows communication between a wide variety of commercially available thermostats, air handlers, control systems, and the SCM-036 & SCM-060 reverse cycle chillers. The ACSCC-5 is used to communicate between a group of air handlers (from two to five) and one or more common banked chillers.
Description: The AC-SCC-5 consists of an integrated circuit board with relay outputs, multiple connection points for thermostats and air handlers, and a step-down transformer providing 24 VAC, mounted inside metal enclosure that can be located at any indoor location. The AC-SCC-5 received power from a 115V or 230V 60 Hz circuit, and transfers 24VAC signals between the thermostats and air handlers. The output signal to the chiller(s) consists of two “dry” contacts, one to enable the chiller and one to determine heating or cooling operation. These switch to open or close the low voltage circuit supplied by the chiller
Section 2: INSTALLATION Installation: Before beginning, ensure all power is removed from the chiller, either at a breaker or disconnect. Mounting and wiring must be accomplished by a qualified technician who is responsible for compliance with all local codes and good practices. 1. Mount the AC-SCC-5 in a dry indoor location that provides easy wiring access from the air handler, and to the outside chiller. The enclosure must be attached securely to a wall or other fixed structure. 2. Pass the control wires from the air handlers and thermostats through the grommet at the lower left of the enclosure, and install them as indicated to the terminal strip at the bottom of the panel. 3. Install a minimum four conductor, single strand 22 or 24 AWG copper, thermostat wire from the interface module, to the chiller. 4. Pass the wire through the grommet at the upper right of the enclosure, and connect one each conductor to the four terminal points marked 7 or 11, 8 or 12 & 43, 44 at the top of the panel. Note the color of the individual wires as these must be connected to the same numbered terminals in the chiller. 5. Using the square bit key supplied with the chiller, remove the access plate on the chiller. 6. At the chiller, pass the control/thermostat wire through one of the grommets in the chiller enclosure not already occupied by the chiller power supply wiring. Take care to route the control wire away from the power wire, to avoid the very small possibility that electrical interference could affect the operation of the chiller. 7. Locate the interface terminal strip. Remove the blue jumper (if installed) between connection points 43 and 44. These are for the remote enable signal. Remove them by inserting a 1/8" (3.5 mm) screwdriver blade or other similar tool into the release slot of the connector, and lifting the handle slightly to depress the spring. This will then free the end of the blue jumper which can be gently pulled out of the wire slot.
8. Next, remove the blue jumper (if installed) from the remote Reversing Valve signal. First identify the serial number of the chiller. Refer to the chart below to determine if the chiller is configuration A or configuration B. For configuration A, removed the jumper between terminals 7 & 8, these are the Reversing Valve signal terminals. For configuration B, removed the jumper between terminals 11 & 12, these are the Reversing Valve signal terminals. 9. While still depressing the spring, install the wires leading from terminals 7/11 & 8/12 of the AC-SCC-5 into the same wire slots. 10. Repeat above steps 8 & 9 at terminals 43 & 44. 11. When all wiring between the thermostats, air handlers, and chiller(s) has been completed, return to the interface panel and connect the power supply. 12. If supplying 115VAC power, connect the Line (hot) wire to the terminal L1 in the interface enclosure, and the Neutral (not ground) wire to the N terminal. Connect the ground wire; bare copper or green, to the Equipment Ground point on the panel. 13. If supplying 230VAC power, connect the L1 (hot) wire to the terminal L1 in the interface enclosure, and the L2 (hot) wire to the L2 terminal. Connect the ground wire; bare copper or green, to the Equipment Ground point on the panel. The neutral terminal will remain empty. 14. Caution! There should never be three wires connected to the L1, N, N2 terminal, one terminal will always remain empty. Never install the ground wire as a neutral, nor the neutral as a ground. 15. Ensure all wire are routed neatly and clear of the access opening, and replace the access panel using the square bit key.
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Model AC-SCC-5 Multi Zone Hydronic Chiller — Installation, Operation & Maintenance Manual
Section 2: INSTALLATION (continued) Figure 1
AirCell module mounting
Terminals 7 & 8
Terminals 11 & 12
Release Slot
Wire Slot
Remove jumper, if present
Chiller identification
AirCell module mounting
Chiller Model
Serial Number Range
Wiring Configuration
SCM-036-A4
A1100222680001001 through A1100222680001025
Configuration A
A1100222680001026 and greater
Configuration B
A1100222680001001 through A1100222680001035
Configuration A
A1100222680002036 and greater
Configuration B
SCM-060-A4
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Model AC-SCC-5 Multi Zone Hydronic Chiller — Installation, Operation & Maintenance Manual
Section 3: OPERATION Testing: 1. When all wire connections have been completed, turn on power to the interface module. The Green, power, LED will illuminate, then either the Red, heat or Blue, cool LED. 2. Set the indoor thermostat, or other control device, to call for heating. (this assumes that the glycol/water solution in the chiller is lower than the heating setpoint. If the temperature is higher, proceed with step 7. 3. Observe that the thermostat, or air handler, sends a signal to call for heating. (Depending on the specific thermostat or air handler setpoints, this may pause for of up to two minutes before reacting.) 4. When the call is sent, wire Y1 will energize the left-most relay in the interface module, producing an audible “click”, and the contacts will close completing the circuit between terminals 43 and 44. 5. The chiller will begin by flashing the Pump symbol for one to two minutes while the control undergoes a self-test. The symbol will then become solid and the pump will begin to circulate. The heating symbol will then begin to flash, again for one to two minutes, and then become solid. At this time, the compressor(s) will engage and the system will begin heating.
7. When the chiller has shut down and the pump stopped circulating, lower the thermostat to initiate a call for cooling. Again, this may pause for up to two minutes. 8. When the call for cooling is sent, the wire Y1 will again energize the left-most relay, and wire O/B will energize the right-most relay, producing an audible “click” and opening the circuit between wires 7 and 8. 9. The chiller start sequence will be the same, except that now the cooling symbol will display.
Control Logic: The default configuration, and above description, assume the following. a. The thermostat and/or air handler energizes the O/B connection in cooling, and de-energizes it in heating. b. The chiller operates in cooling when circuit 7 & 8 (or 11 & 12) is open, and heating when circuit 7 & 8 (or 11 & 12) is closed. If either of these conditions is not true, causing the chiller to function opposite to the description above, the operation of the interface module can be reversed by simply relocating wire 7 (or 11), at the right-most relay, from the NC terminal to the NO terminal.
6. Lower the thermostat to remove the call for heating, and allow the chiller to complete its shutdown cycle, running for two to three minutes.
Figure 2
Chiller display
Heating Symbol Cooling Symbol Pump Symbol
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Model AC-SCC-5 Multi Zone Hydronic Chiller — Installation, Operation & Maintenance Manual
Section 3: OPERATION (continued) Troubleshooting: Condition Chiller does not respond to call for conditioning.
Possible cause
Solution
Voltage not supplied to interface module.
24VAC power must be present between the blue and yellow wires of the transformer.
Time delay has not elapsed
Verify that the thermostat or air handler delay has timed out and voltage is being supplied to the interface module.
Disconnected or broken wire.
Physically inspect the condition of the wires between the thermostat, air handler and the interface module, and between the interface module and the chiller.
No power to the chiller
Ensure the chiller always has 230VAC power connected, display must remain active at all times.
Chiller operates in cooling when called upon for heating, or heating when called upon for cooling.
Logic is reversed at one component.
Reverse the logic of the control board.
Power LED illuminates, but not heat or cool LED’s, relays chatter or buzz, or no signal to chiller
Improper voltage to circuit board.
Verify 21 to 27 volts at the transformer output. Ensure power supply is wired according to installation steps 11 or 12.
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Model AC-SCC-5 Multi Zone Hydronic Chiller — Installation, Operation & Maintenance Manual
Section 3: OPERATION (continued) Electrical Diagram
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Model AC-SCC-5 Multi Zone Hydronic Chiller — Installation, Operation & Maintenance Manual
Section 3: OPERATION (continued) Auto Rotation Switch ‘OFF’
Appendix A: Functionality
Manual Switch ‘AUTO’
Overview The SpacePak RCB operates up to 5 air handlers with a single chiller or bank of chillers. One specific thermostat (i.e. a master) will set the system mode as heating or cooling. Air handlers will each be energized on a call for heating or cooling from their corresponding thermostat only if requesting the same mode as the system. Until the system mode changes, the chiller will remain in the same mode (heating or cooling). The relay control board will also display operational and diagnostic feedback on LEDs. It will have control of whether or not an air handler gets the G signal from their corresponding thermostat. This will allow the fan to run on the air handler when the operating mode permits. Fan only mode will be supported and if a thermostat calls for cooling when the system mode is in heating, the slave will not receive chilled water, and the respective air handler fan will stay on, until the system mode changes to cooling. The thermostat will send a signal to the relay board which will in turn send signals to the chiller, air handler and air handler pump/valve. Individual airhandlers will respond to a fan-only call for air circulation only if the thermostat is capable of supplying this signal.
LED Descriptions LEDs on the thermostat side: •
Green LED – Fan input signal coming from thermostat.
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Yellow LED – Y signal coming from thermostat.
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Red LED – OB signal coming from thermostat.
LEDs on the Air Handler side: •
Green LED – Fan output signal going to the air handler.
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Yellow LED – Y output signal going to air handler. Air handler is enabled.
System mode LEDs: •
‘POWER’ (Green LED) – Signifies that there is power to the board. It is always on if there is power and does not change.
•
‘COOL’ (Blue LED) – System mode is cooling. If this LED is not held constant (i.e. it is blinking or on with the ‘HEAT’ LED) it is showing different functionality.
•
‘HEAT’ (Red LED) – System mode is heating. If this LED is not held constant (i.e. it is blinking or on with the ‘COOL’ LED) it is showing different functionality.
Power Up The SpacePak Relay Control Board will power up when 24VAC is connected to its respective 24VAC terminal block. If for some reason the board needs to be power cycled, disconnect the 24VAC and then reconnect it.
The thermostat connected to the ‘MASTER TSTAT’ position is designated as the master. This thermostat governs the mode of the entire system. If this master thermostat calls for cooling then the system mode is changed to cooling. If it calls for heating then the system mode is changed to heating. When the master is satisfied and is not calling for heating or cooling, the system mode stays in the same mode it was in. For example, if the master was calling for heating and then becomes satisfied and stops calling, the system mode stays in heating. When the Master thermostat is calling for either heating or cooling its air handler will be enabled (Yellow LED on). If there is a fan signal present from the master thermostat, it will also be passed on to the air handler (Green LED on). All other thermostats connected to the ‘MEMBER # TSTAT’ positions are the members. When a member thermostat calls for heating and is in agreement with the system mode (system is in heating), then its air handler will be enabled and fan signal will be passed through. If a member thermostat calls for heating and is not in agreement with the system mode (system is in cooling), then its air handler will be disabled and fan signal will not be passed through. When a member thermostat calls for cooling and is in agreement with the system mode (system is in cooling), then its air handler will be enabled and fan signal will be passed through. If a member thermostat calls for cooling and is not in agreement with the system mode (system is in heating), then its air handler will be disabled and fan signal will still be passed through. As long as there is at least one thermostat calling that is in agreement with the system mode, the chiller will be enabled and its reversing valve will be enabled depending on the system mode. If all thermostats are satisfied and there is no call then the chiller will be disabled and there will be no reversing valve signal. If there are only members calling that are not in agreement with the system mode then the chiller will remain disabled and there will be no reversing valve signal present. Manual Switch ‘HEAT’ The system mode is set to heating and cannot be changed to cooling by any thermostat demand. All functionality mentioned in the Manual Switch ‘AUTO’ section remains the same except the system mode is always in heating and the master thermostat (‘MASTER TSTAT’) now behaves as a member thermostat. Manual Switch ‘COOL’ The system mode is set to cooling and cannot be changed to heating by any thermostat demand. All functionality mentioned in the Manual Switch ‘AUTO’ section remains the same except the system mode is always in cooling and the master thermostat (‘MASTER TSTAT’) now behaves as a member thermostat.
On power up the ‘POWER’ LED will come on and remain on. Either the ‘COOL’ LED or the ‘HEAT’ LED will blink three times. If the ‘COOL’ LED blinks three times then the reversing valve is set to be energized with an O signal. If the ‘HEAT’ LED blinks three times then the reversing valve is set to be energized with a B signal. After the three blinks occur, the system mode will set to its default mode of heating and the ‘HEAT’ LED will come on.
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Model AC-SCC-5 Multi Zone Hydronic Chiller — Installation, Operation & Maintenance Manual
Section 3: OPERATION (continued) Auto Rotation Switch ‘ON’
Manual Switch ‘HEAT’
Manual Switch ‘AUTO’
If there are no calls from any thermostats then the chiller’s reversing valve mode changes to be energized when there is a B signal present. The ‘HEAT’ LED will blink until the manual switch is set back to the ‘AUTO’ position. While waiting for the switch to go back into the ‘AUTO’ position, all inputs from the thermostats as well as the Auto Rotation switch will have no effect. However, G signals will still be able to be passed through. After the ‘AUTO’ position has been selected, the system mode will return to the state it was in before the ‘HEAT’ position was selected.
There is no master thermostat and all thermostats behave in the same way. After all of the thermostats are satisfied and not making calls, the first thermostat to reinitiate a call sets the system mode. As long as there is at least one thermostat making a call that is in agreement with the system mode then the system mode cannot be changed. Once all of the thermostats that were in agreement with the system mode are satisfied then the system mode can be changed. If there were thermostats making opposite calls simultaneously, the system mode will switch once all thermostats in agreement are satisfied. If all thermostats that were making calls that were in agreement are satisfied then the system mode will be determined by the first thermostat to reinitiate a call. When a thermostat calls for heating and is in agreement with the system mode (system is in heating), then its air handler will be enabled and fan signal will be passed through. If a thermostat calls for heating and is not in agreement with the system mode (system is in cooling), then its air handler will be disabled and fan signal will not be passed through. When a thermostat calls for cooling and is in agreement with the system mode (system is in cooling), then its air handler will be enabled and fan signal will be passed through. If a thermostat calls for cooling and is not in agreement with the system mode (system is in heating), then its air handler will be disabled and fan signal will still be passed through. As long as there is at least one thermostat calling then the chiller will be enabled and its reversing valve will be enabled depending on the system mode. If all thermostats are satisfied and there is no call then the chiller will be disabled and there will be no reversing valve signal.
If there are calls from any thermostats then the reversing valve mode will not change, all air handler outputs will be disabled and the ‘HEAT’ and ‘COOL’ LEDs will blink back and forth. This will continue until the manual switch is set back to the ‘AUTO’ position. While waiting for the switch to go back into the ‘AUTO’ position, all inputs from the thermostats as well as the Auto Rotation switch will have no effect. After the ‘AUTO’ position has been selected, the system mode will change to heating. Manual Switch ‘COOL’ If there are no calls from any thermostats then the chiller’s reversing valve mode changes to be energized when there is an O signal present. The ‘COOL’ LED will blink until the manual switch is set back to the ‘AUTO’ position. While waiting for the switch to go back into the ‘AUTO’ position, all inputs from the thermostats as well as the Auto Rotation switch will have no effect. However, G signals will still be able to be passed through. After the ‘AUTO’ position has been selected, the system mode will return to the state it was in before the ‘COOL’ position was selected. If there are calls from any thermostats then the reversing valve mode will not change, all air handler outputs will be disabled and the ‘HEAT’ and ‘COOL’ LEDs will blink back and forth. This will continue until the manual switch is set back to the ‘AUTO’ position. While waiting for the switch to go back into the ‘AUTO’ position, all inputs from the thermostats as well as the Auto Rotation switch will have no effect. After the ‘AUTO’ position has been selected, the system mode will change to cooling.
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Model AC-SCC-5 Multi Zone Hydronic Chiller — Installation, Operation & Maintenance Manual
Section 3: OPERATION (continued) Appendix B: Flow Diagram SpacePak relay control board flow diagram
AirCell module mounting
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Model AC-SCC-5 Multi Zone Hydronic Chiller — Installation, Operation & Maintenance Manual
Section 3: OPERATION (continued) Appendix B: Flow Diagram Master thermostat
AirCell module mounting
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Model AC-SCC-5 Multi Zone Hydronic Chiller — Installation, Operation & Maintenance Manual
Section 3: OPERATION (continued) Appendix B: Flow Diagram Slave thermostat
AirCell module mounting
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Model AC-SCC-5 Multi Zone Hydronic Chiller — Installation, Operation & Maintenance Manual
Section 3: OPERATION (continued) Appendix B: Flow Diagram Auto rotation
AirCell module mounting
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