Specifications

35
© 2012 Emerson Climate Technologies, Inc.
Printed in the U.S.A.
AE8-1368 R2
No Communication to Rack Controller
(Continued)
6.14b
Amber or Red
lights of all or
several
compressors are
continuously ON
Verify that the RS485
connector polarity is
correct at the controller
or at each compressor
Problem
persists?
Done
Unplug the RS485
connector on all
compressors, plug back
one at a time to isolate
which compressor is
causing the problem
When the trouble compressor is
identified:
- Look for grounded (pinched)
low pressure switch lead under a
fan bracket leg
- Unplug the oil pressure harness.
If the problem goes away, replace
the oil sensor
Does the
problem
persist?
Look elsewhere for a location on the
harness that is grounded to the
compressor. If the fault comes and goes
with the compressor run requests, look
on the pilot circuit wires or pressure
switch leads. Other possibilities include
the unloader harness wires.
Yes
No