Transcript
Vibration Monitor VIB-20A Installation and Using Instructions
TRV-12 TRV-13 46044-L 46045-L
ALERT: Relay switches at preset level (“Maintenance needed)
81030 81031 VIC-17
VIB-20A
Technical Data Monitor VIB-20A Measuring range: Relay outputs: Analog output: Mains power: Temperature range: Casing: Dimensions:
81027
TRX-18 TRX-19
ALARM: Relay switches at preset level (“Danger, emergency shutdown“)
81057
Part Numbers ALERT 2 - 20 mm/s RMS ALARM 2 - 60 mm/s RMS max 220 V, 100 VA 4 to 20 mA 230/115 V, 50 - 60 Hz 0° C to + 55° C (32° F to 131° F) Polyester, IP 65 170 x 105 x 82 mm (6.7" x 4.1" x 3.2")
Transducer TRV-12/13
Design: Weight: Connector type:
12 pC/m/s ± 15% max. 10% 0.01 m/s2/µ strain 10 to 1000 Hz 600 m/s2 –30° C to +150° C (–22° F to +302° F) 0.25% / °C Stainless, acid proof steel, SS 2382 / AISI 316 Sealed 135 grams (5 oz) TNC
Torque limit:
10 Nm (7.4 lbf · ft)
Nominal sensitivity, main axis: Transverse sensitivity: Typical base strain sensitivity: Linear frequency range: Max. peak acceleration: Temperature range: Typical temperature drift: Casing:
2
VIB-20A
Vibration monitor
VIC-17
Pointer instrument
TRV-12
Vibration transducer, M 8
TRV-13
Vibration transducer, UNF 1/4"-28
TRX-18
Insulated installation foot M 8
TRX-19
Insulated installation foot UNF 1/4"-28
46044-L
Measuring cable with standard TNC connectors (–10° to +70° C)
46045-L
Measuring cable with one standard and one sealing TNC connector (–10° to +70° C)
81027
Holder for counterbore
81057
Counterbore, diam. 20 mm
81030
Pilot for UNF 1/4" (TRV-13)
81031
Pilot for M8 (TRV-12)
NB. When ordering measuring cables, please state desired length (L) in metres. Max. cable length is 10 m. For information on high temperature coaxial cables, moisture proof connectors, etc., please contact SPM.
ANALOG: 4 – 20 mA, proportional to measured vibration level. 230 /115 V 50 – 60 Hz
General functions VIB-20A is intended for continuous monitoring of industrial fans and other machinery which can be subjected to sudden, dangerous increases of the vibration level. The monitor has two adjustable alarm levels and measures the vibration severity (= velocity in mm/s RMS) according to ISO 2372. The detector provide an analog current, proportional to the measured vibration severity. It will trigger the the alarm relay when the transducer signal exceeds a preset alarm level. An alarm is reset automatically when the vibration level decreases below the trigger level. VIB-20A is normally mounted on the machine.
Technical functions The equipment is supplied with either 230 V or 115 V, at 50 – 60 Hz. It has two separate measuring circuits, each with a voltage free relay output (max. 220 V/100 VA). ALERT is preset continuously within a measuring range of 2 – 20 mm/s RMS. The ALERT relay is activated when the transducer signal exceeds preset alarm level. ALARM is preset in multiples (1 – 3) of the preset ALERT value. The ALARM relay is activated when the transducer signal exceeds preset ALERT x ALARM value.
SPM Instrument AB • Box 4 • S-645 21 Strängnäs • Sweden Tel +46 152 22500 • Fax +46 152 15075 •
[email protected] • www.spminstrument.se
Technical data are subject to change without notice. © Copyright SPM 1998-02. 71513.B
In addition, VIB-20A has an analog output supplying 4 – 20 mA, proportional to the measured vibration level. The scaling of the output current is a function of the preset ALERT value. When the machine vibration is equal to the ALERT setting, the analog output always supplies 12 mA. At a vibration level of twice the preset ALERT value, the output is maximum, i.e. 20 mA.
Presetting alarm level
54
36
ø 27.5
Cable clamp
t
Installation of Transducer TRV-12/13
min. 10
82
105
153
210
For spot-facing of the contact surface, use a counterbore with a diameter of min. 16 mm. Spot-face to a depth of max. 0.7 mm. Torque and unscrew the transducer with a torque wrench and a 17 mm socket (SPM 81092). The maximum torque is 10 Nm.
(UNF 1/4"-28) max. 0.7
The transducer is mounted against a smooth, flat surface on the machine. Mount insulated installation foot TRX-18 (TRX-19) on the transducer to obtain an insulated installation. The transducers are delivered with three washers for adjusting the connector angle. Each washer turns the transducer 90°.
M8
min. 16
ø 6.9 (ø 5.5) min. 12
Machine vibration at the pick-up point shall be representative of the overall vibration level of the machine. On fans and other rotating machinery, the transducer is normally mounted on the rotor bearing, with its main axis pointing in a horizontal direction. Placed in this position, it is most sensitive to changes in rotor balance.
TRV-12: t = M8 TRV-13: t = UNF 1/4"- 28
ø 15
170
The choice of suitable limit values can be based on experience, on manufacturer’s recommendations or on ISO 2372 (BS 4675/1 : VDI 2056). A summary of the international recommendations is given on page 3.
17
9
The ALARM relay is used to trigger an automatic shutdown and/or an external alarm when vibration reaches a dangerous level.
Selecting Suitable Alarm Levels
Measuring direction
The ALERT relay is normally used to trigger an external warning device at a vibration level where the machine needs maintenance.
Installation of Measuring Cable
Important: To avoid disturbances, the cable has to be clamped.
Electric connections
Mains power 230 V/115 V, 50-60 Hz power consumption 5 VA
ALERT relay
According to these definitions, most smaller process pumps, for example, would be Class II. A 100 kW ventilation fan on a concrete base would be Class III. However, the same fan fastened to the less rigid metal deck of a ship would be considered as Class IV. The international recommendations are of a general nature, and should be supplemented by limit values obtained from the machine manufacturer. One can also use a measurement of the actual vibration level as a starting point. Measure the vibration severity while it is reasonably sure that the machine is in good condition. This can be done by turning the ALERT adjusting screw until an alarm is triggered. Following the ISO table, the limit value for “maintenance needed“ should be 2.5 times the normal vibration level of the machine. ALERT can be adjusted accordingly. A suitable ALARM setting is 2 or 2.5. Thus, shutdown alarm is triggered when vibration increases 5 to 6 times above the normal level.
Testing the equipment is best done by manual vibration measurement with Vibrameter VIB-10.
mm/s RMS
Class I Individual parts of engines and machines, integrally connected with the complete machine in its normal operating condition. (Production electrical motors of up to 15 kW are typical examples of machines in this category).
ClassII Medium-sized machines, (typically electrical motors with 15 to 75 kW output) without special foundations, rigidly mounted engines or machines (up to 300 kW) on special foundations.
Class III Large prime movers and other large machines with rotating masses mounted on rigid and heavy foundations which are relatively stiff in the direction of vibration measurement.
Class IV Large prime movers and other large machines with rotating masses mounted on foundations which are relatively soft in the direction of vibration measurement (for example turbogenerator sets, especially those with light-weight substructures).
Class V 4 x ø4.5
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Installation of Monitor VIB-20A The monitor is mounted in a place where it is not exposed to strong vibrations. Its polyester casing is dust and hose tight. The temperature range is 0° to +55° C. The maximum cable length between transducer and monitor is 10 m (33 ft).
230 V 115 V
Class
A machine’s vibration class depends on its size and function as well as on the stiffness of its foundation. Class definitions according to ISO 2372 and BS 4675 are given in the table below. VDI 2056 recommends a similar grouping.
Function test
The low-noise cable SPM 46044-L is supplied with mounted TNC connectors. For installations in moist environments, use cable SPM 46045-L with sealing TNC connector (SPM 13008) to prevent cable corrosion. The cables have a temperature range of -10° to +70° C. They have good resistance against most chemicals, but not against oils. If a high temperature cable is needed, please contact SPM.
The international standards dealing with vibration measurement group industrial machinery into six different vibration classes. For each class, they give vibration severity levels in four bands, ranging from good condition through average and poor to bad. From each band to the next, vibration changes by a factor of 2.5 (see adjacent table).
Limit value
ALARM relay
Max. 220 V, 100 VA. The fig. shows the relay’s normal position without alarm. (The ALERT relay switches even at power failure).
Analog signal 4 - 20 mA max. load 300 Ω not galvanically separated.
Disconnect the measuring cable from the vibration monitor VIB-20A. Attach the cable to the vibration meter VIB-10 and measure the actual vibration severity. Reconnect the coaxial cable to the VIB-20A and adjust the ALERT value by turning the adjusting screw slowly downwards until the level is reached where the ALERT relay is activated, i.e. the LED marked ALERT lightens. The mark on the adjusting screw should now point to a value coincident with the measured value ± (10% of the reading + 0.5 mm/s). It is of importance that the operating condition and thus the vibration situation is equal at the two measuring occasions.
Machines and mechanical drive systems with unbalanceable inertia effects (due to reciprocating parts), mounted on foundations which are relatively stiff in the direction of vibration measurement.
Class VI Machines and mechanical drive systems with unbalanceable inertia effects (due to reciprocating parts), mounted on foundations which are relatively soft in the direction of vibration measurements; machines with rotating slackcoupled masses such as beater shafts in grinding mills; machines, like centrifugal machines, with varying unbalances capable of operating as selfcontained units without connecting components; vibrating screens, dynamic fatigue-testing machines and vibration exciters used in processing plants.
