Specifications

36
© 2012 Emerson Climate Technologies, Inc.
Printed in the U.S.A.
AE8-1368 R2
Motor Temperature Trip
Motor temperature protection for 4D and 6D compressors utilizes
3 temperature sensors in the motor. The temperature sensor
resistance is measured by the control module to determine
whether or not to shut down the motor. The motor temperature
set point is not configurable (it is a fixed value).
Normal reset requires that the compressor be off for 2 minutes
and the sensor temperatures be below a reset resistance (see
below)
Caution: High Voltage Inside
Terminal Box
Check the motor sensor
resistance (this may be checked
at the control module by
unplugging the low voltage
harness
Motor Sensor Resistance
Values:
Cold: 20 – 100 ohms
Reset after trip: 2750 ohms
Allow the compressor to cool for
one hour. Verify proper nut
torque (20 in-lb) of motor
temperature terminal strip nuts in
the terminal box. The sensor to
common resistance on a cold
motor should be between 20 and
250 ohms. Reset values for a hot
motor are 2700 – 4500 ohms.
Are the
sensors within
spec?
See emergency
bypass
instructions above
No
Possible Causes:
1.) Open circuit in harness
2.) Connector pin not
engaging at connector on
control module
3.) Faulty control module
Yes
Open end view of low voltage harness,
unplugged from the control module
C S1 S2 S3
OR Bk Bk Bk
Low Voltage Connector
6.15
Does the fault
remain?
Resolve source of
high motor
temperature
Yes
No
Verify that the low voltage connector is
plugged into the control module
Emergency Sensor Bypass Instructions:
In t he unlik ely event that ONE sensor
may be damage d and have an op en
circuit, the con trol module will prevent
compressor operation even though the
motor may b e in oth erwise perfe ct
condition. If su ch a situa tion should be
encountered in the fiel d , an em ergency
means of operating the compressor can
be us ed until s uch time as a
replacement can be made . Disconnect
the orange lead that is connected to the
faulty sensor , and mov e it to th e
common (black wire ) post. Stack the
two rin g terminal s (one bla ck and one
orange) together on the common post.