Carlyle Compressor Div. P O Box 4808 Syracuse, NY 13221
Phone: 800-462-2759 Fax: 315-432-3274
2
1.0 Overview
The LonCEM is a solid state electronic module used as the primary compressor
protection for our 74mm screw compressors. It is used on both our semi-hermetic (06T)
and open-drive (05T) air conditioning and refrigeration compressors. Special
instructions for 05T installations are provided in Section 3.4. The module provides
thermal compressor protection by monitoring motor and discharge temperature and
providing liquid injection cooling as required. Oil pressure protection is provided by
monitoring suction, discharge and oil pressure. Pressure drop through the oil system (oil
filters, oil cooler, oil line solenoid etc.) is continuously monitored to insure proper oil flow.
Other features include reverse rotation protection, 20 second time-delay between
compressor starts, volume index control for refrigeration models, and startup sequencing
of the oil and economizer solenoid valves. A functional overview providing details on
each module function is presented in Appendix A.
A LonWorks
®
version of the module is available, allowing communication over a
LonWorks
®
control network. Through the network, the module can be instructed to
provide on/off and unloading control. In addition, all module inputs including: suction
pressure, discharge pressure, oil pressure, motor temperature, and discharge
temperature are available for data logging and/or as input to another controller.
The module will be available as part of a package including all necessary sensors, wiring
harnesses, and fittings. The remainder of this document provides a comparison of the
old and new protection modules, bill of materials of the LonCEM module packages,
installation instructions, trouble shooting and application notes, and a description of the
sensor inputs and control outputs. Appendix E summarizes the conversion of the sensor
outputs to engineering units, which is helpful when diagnosing sensor and operational
problems.
1.1 Old CEM versus New LonCEM
The new LonCEM Packages (see section 2.0 for Bill of Materials) replace the older style
CEM (P/N 3TA0796B). The newer style module incorporates 3 pressure transducers (in
addition to the motor and discharge thermistor inputs used on the old module), which
eliminate many of the previously required electro-mechanical pressure switches. The
following items are no longer required when using the new LonCEM packages:
Description P/N
Older Style CEM 3TA0796B
Oil Pressure Protection Switch HK06ZB006
Reverse Rotation Switch HK01CB002
Oil Filter Protection Switch HK06CA051
5k Thermistor* HH79NZ065
Electronic Phase Monitor** P251-0090
* Still required, but is included in LonCEM package (see section 2 for complete BoM)
** Was never required but offered as an option for reverse rotation protection.
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