8
© 2011 Emerson Climate Technologies
Printed in the U.S.A.
AE8-1384 R1
Application Engineering
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SERVICE
Field Service
Service compressors will be shipped with the CoreSense
Communications module installed in the compressor
terminal box. Special attention should be given to the
module DIP switch settings of the compressor being
replaced so the DIP switch settings can be transferred
to the module of the replacement compressor. As
mentioned earlier, the CoreSense Communications
module is a recognized safety device and shall be used
only with approved compressors with TE* motor codes.
NOTICE
If a compressor with CoreSense Communications
fails in the
fi
eld, the CoreSense module should
remain with the failed compressor so Emerson
technicians can download the CoreSense data
to assist with determining the root cause of
compressor failure.
Troubleshooting
WARNING
Always disconnect and lockout the power supply
before removing the compressor electrical box
cover for servicing.
For troubleshooting purposes the scroll and motor
thermistor circuits are similar to those of other Copeland
Scrolls with one exception, the scroll thermistor is a
negative temperature coef
fi
cient (NTC) type thermistor.
This means that as the discharge temperature
increases, the resistance of the thermistor decreases.
The motor has positive temperature coefficient
(PTC) type thermistors; as the motor temperature
increases, so does the resistance of the thermistor
chain. To measure the resistance of the PTC and NTC
circuits simply remove the temperature plug from the
CoreSense module and measure the resistance in the
appropriate pins shown in
Figure 4
. The measured
values should be in the ranges listed in
Table 2
. For
information on trouble shooting causes of high motor
and scroll temperatures please refer to the application
engineering bulletin for the compressor.
A loss of communications with the master controller for
more than
fi
ve minutes is communicated via a green
fl
ash code 1 if DIP switch #8 is enabled. CoreSense
Communications has no provisions to detect incorrect
wiring neither between daisy chained modules nor to
the master controller. Ideally, the master controller will
contain advanced troubleshooting menus for help in
diagnosing communications issues between the master
controller and the CoreSense module.
