
CMC TECHNICAL REFERENCE MANUAL
1X36003 Version 2.52
1996-1999 Ingersoll-Rand Company
Date of Issue: 18-Oct-1999
Table of Contents
What’s New In This Manual_____________________________________________ 1
References __________________________________________________________ 2
General - CMC Panel __________________________________________________ 3
Control Methodology __________________________________________________ 4
Performance Control ________________________________________________________4
Unload _____________________________________________________________________________ 4
Constant Pressure Control - Modulate ____________________________________________________ 4
Energy Saving Control - Autodual ________________________________________________________ 5
How does Constant Pressure Modulation Work? _________________________________________ 6
Measuring the Discharge Pressure __________________________________________________ 6
Proportional Band ________________________________________________________________ 7
Integral Time ____________________________________________________________________ 7
Motor Current, MinLoad and MaxLoad________________________________________________ 8
Surge Control _____________________________________________________________10
Control Methodology _________________________________________________________________ 10
Surge Detection _____________________________________________________________________ 10
Insufficient Rise To Surge ___________________________________________________________ 10
Changes in System Discharge Pressure _______________________________________________ 11
Rapid System Demand Changes _____________________________________________________ 11
Incorrect Instrumentation Output _____________________________________________________ 12
How is Surge Detected? ____________________________________________________________ 12
Surge AbsorberTM ___________________________________________________________________ 12
Surge Indexing ______________________________________________________________________ 13
Oil System Control___________________________________________________ 14
Prelube Pump _____________________________________________________________14
Oil Heater_________________________________________________________________14
Protection and Monitoring_____________________________________________ 15
Analog Functions __________________________________________________________15
Analog Inputs _______________________________________________________________________ 15
Analog Outputs _____________________________________________________________________ 15
Digital Functions ___________________________________________________________15
Digital Inputs _______________________________________________________________________ 16
Digital Outputs ______________________________________________________________________ 16
Compressor Operating Methodology ____________________________________ 17
Stopped __________________________________________________________________17
Waiting ____________________________________________________________________________ 17
Not Ready _________________________________________________________________________ 17
Ready _____________________________________________________________________________ 17
Rotating __________________________________________________________________17
Starting____________________________________________________________________________ 17
Unloaded __________________________________________________________________________ 18