Specifications

24
© 2012 Emerson Climate Technologies, Inc.
Printed in the U.S.A.
AE8-1368 R2
6.4 Emergency Work-Around Procedures
In the event that a compressor fails to run due to an
electronic module failure, the following work-around
procedures are listed to assist the technician with
gaining temporary control of the compressor until
replacement parts may be obtained. The situations
listed below will not compromise the fundamental safe
operation of the compressor or agency listed motor
protection features. There will be some increased risk
of compressor damage associated with the loss of the
module’s functionality. The service technician must
determine whether the risks of temporarily running the
compressor in this situation are warranted.
Refer to the troubleshooting charts in the following
sections before resorting to these emergency service
options.
Controller fails to call the compressor “on” but
network communication is active:
Unplug the RS485 connector at the control module.
Set the “failsafe” dipswitch to the “run” position and
then press the control module “reset” button. After 5
minutes the compressor will run in the failsafe mode.
Pressure switch and motor protection features will
still function.
Failed discharge temperature probe resulting in
false discharge temperature trip:
Unplug the discharge temperature probe. This will
generate “Fault Temperature Probe” warnings but
will not prevent the compressor from running.
False motor trips or lockouts:
Faults that are associated with the sensor module or
current sensor (see Figure 6.1 above) are advanced
protection features beyond the basic motor
temperature or current limiting protection available
on all discus compressors. If troubleshooting leads
to the conclusion that the trips or lockouts are false,
the sensor module communication harness may
be unplugged from the control module. This will
generate a “no communication to sensor module”
warning but will allow the compressor to run. If the
sensor module communication is unplugged - all
of the advanced motor protection features will be
bypassed. If the problem is associated with the
current sensor itself, this may be unplugged from the
sensor module leaving fundamental communication
between the sensor and control module intact.
Emergency By-Pass Procedure:
Refer to Section 6.13: Fail-Safe Inoperable.