Service; Field Service; Troubleshooting - Emerson CoreSense Application Engineering Bulletin

The RS-485/USB adapter used to connect the laptop to the
CoreSense is Emerson part number 929-0011-00.
For more information on the PC interface software, how to
obtain it, and a tutorial on its use, please contact your
Application Engineer.

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
NOTICE
If a compressor with CoreSense Communications
fails in the field, the CoreSense module should remain
with the failed compressor so Emerson technicians
can download the CoreSense datato assist with
determining the root cause of compressor failure.

Troubleshooting

WARNING
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
© 2018 Emerson Climate Technologies, Inc.
Scrolls with one exception, the scroll thermistor is a
negative temperature coefficient (NTC) type thermistor.
This means that as the dis-charge 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 3. 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 five minutes is communicated via a green flash
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.
NOTICE
NOTICE
In some rare cases communication between the master
controller and the CoreSense module is problematic.
Reversing the polarity will re-initiate communication.
To reverse polarity:
1. Adjust CoreSense to negative
2. Adjust master controller to positive
8
PRELIMINARY
AEX-XXXX
AE8-1384 R6