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CMC TECHNICAL REFERENCE MANUAL
1X36003 Version 2.52
1996-1999 Ingersoll-Rand Company
Date of Issue: 18-Oct-1999
3
General - CMC Panel
The CMC panel is the microprocessor-based control and monitoring system for Centac and
X-FLO centrifugal compressors. The CMC handles all pressure control and monitoring
functions; as well as, control auxiliary equipment such as the main motor starter, oil heater,
and prelube pump.
The CMC panel has a custom designed computer board called the Base Control Module
(BCM). This board has a microcontroller and memory chips that tell the rest of the panel
what to do for the various input pressures, temperatures and vibrations. All hardware for
data analysis, number of input and output (I/O) points and system memory are optimally
selected for accurately controlling and protecting Centac and X-FLO compressors.
Features of the CMC system are:
•
Ease of use ... only twelve buttons to push on the operator OUI!
•
Multiple function, 240 x 128 pixel graphic LCD display to display data and operating status
•
Unload, Modulate and Auto-Dual operating modes.
•
Advanced surge detection and control.
•
High current limit for main drive electric motor protection.
•
First-out indication and event log to help determine the root cause of a compressor trip.
•
Pinion vibration alarm and trip for each compression stage.
•
Optional port for communicating to the Centac Energy Master (CEM) or other Distributed
Control Systems (DCS) via MODBUS protocol.
•
Optional reduced voltage motor starter included in panel for some sizes.
NOTE
For the purpose of consistency and clarity, all of the descriptions and examples that
follow refer to "air" for the more generic "gas". Any gas compressed by a Centac or X-
FLO compressor would also apply.