Honeywell UDC2500 - Manual (Page 180)

Troubleshooting/Service
166 UDC2500 Universal Digital Controller Product Manual 4/07
Procedure #1
Table 7-5 explains how to troubleshoot power failure symptoms.
Table 7-5 Troubleshooting Power Failure Symptoms
Step What to do How to do it
1 Check the AC line voltage. Use a voltmeter to measure the AC voltage
across terminals L1 and L2 on the rear
terminal panel of the controller.
Check the earth ground connection.
2 Make sure the chassis plugs
into the rear of the case
properly. Withdraw the chassis and visually inspect the
controller board and the inside of the case.
3 Check the system for Brown-
outs, heavy load switching, etc.,
and conformance to installation
instructions. Refer to Section 2 - Installation.
4 Change Power board. Installation instructions supplied with new
board.
Procedure #2
Table 7-6 explains how to troubleshoot Current Output failure symptoms.
Table 7-6 Troubleshooting Current Output Failure
Step What to do How to do it
1 Make sure the controller is
configured for Current output
and the proper range (4 to 20 or
0 to 20) is configured. Make Output Set Up group function prompt
OUT ALG = CUR.
Make the Output Set UP group function
prompt CRANGE = 4–20 or 0–20 per your
application.
Refer to Section 3 - Configuration.
2 Check the field wiring. Output impedance must be less than or equal
to 1000 ohms.
3 Check the output. Put the controller into Manual mode and
change the output from 0 % to 100 % (4-20
mA). Use a DC milliammeter at the rear
terminals to verify the output.
4 Recalibrate the Current
Proportional output. Refer to Section 6 - Output Calibration for
details.
5 Change Current Output board. Installation instructions provided with new
board.
6 Change Controller