Trane VAV-UCM 4.2, Инструкция по установке и обслуживанию

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70 VAV-SVX01C-EN
Troubleshooting
• Remove the high and low tubes from the transducer (to simulate no flow). Read the
transducer output voltage on J3 of the UCM board between the green and the black wires
with a voltmeter. The voltage should be between 0.20 volts DC and 0.30 volts DC (0.25 volts
DC is the null voltage output of the transducer indicating zero flow). If voltage not available
replace transducer
Note: The formula for the Transducer output voltage is 0.25 + 0.75 * <delta P>, where delta P
is the pressure in inches of water column. Delta P can range from 0 to 5 inches of W.C.
• With flow across the flow ring measure the differential pressure with a magnahelic and use
Transducer output voltage formula to check accuracy of reported value. Read the transducer
output voltage between the green and the black wires. The measured value should
correspond to the value given in the transducer output formula. If transducer is off by ± 5%,
replace transducer.
Auxiliary Temperature Sensor Failure Procedures
In the event that the UCM reports an incorrect or failed Auxiliary temperature, properly inspect the
following:
1. Make sure VAV UCM has been configured for auxiliary input
2. Actual auxiliary temperature is higher or lower than what the UCM reads
• Check the location and installation of the Auxiliary zone sensor. Change the calibration factor
in the UCM setup screens.
Note: If Auxiliary sensor is off more than ± 2 degrees continue to number 3.
Figure 40. UCM setup screen