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CMC TECHNICAL REFERENCE MANUAL
1X36003 Version 2.52
1996-1999 Ingersoll-Rand Company
Date of Issue: 18-Oct-1999
Troubleshooting
The following procedures provide direction on troubleshooting the CMC System, control
panel, and associated instrumentation. Faults are either Event Logged, which means the
fault is displayed in the INFO Folder on the OUI, or Non-Event Logged. The distinction helps
to expedite the troubleshooting process.
When a control system fault is suspected, the following diagram is used to categorize the
fault. The section following the diagram breaks each category down into specific items,
which can cause a particular fault.
I/O FAULT
Temperature, pressure, load, valve, etc.
readings incorrect.
(Refer to the Input/Output (I/O) System)
COMPRESSOR RELATED
Event correctly indicates a problem.
(Refer to the compressor operating manual)
STABILITY PROBLEMS
Inlet valve, bypass valve, or control variables
(mass flow, system pressure, Kw, amps) are
unstable.
(Refer to the CMC Tuning Procedures Section)
CONTROL PROBLEMS
Compressor fails to Load, fails to trip, fails to
start, surging, etc.
(Refer to the CMC Tuning Procedures section)
CONTROLLER PROBLEMS
OUI failed, BCM failed, UCM failed,
Communications failed.
(Refer to Controller Problems Section)
A CONTROL
SYSTEM FAULT IS
SUSPECTED
THE FAULT IS LOGGED IN
THE EVENT LOG.
THE FAULT IS NOT LOGGED IN
THE EVENT LOG
Figure 12: Troubleshooting Tree