Trane RRU150F N Series Installation, Operation And Maintenance Manual page 47

RTRM Failure Modes
WARNING
Live Electrical Components!
Failure to follow all electrical safety precautions when
exposed to live electrical components could result in
death or serious injury.
When it is necessary to work with live electrical
components, have a qualified licensed electrician or
other individual who has been properly trained in
handling live electrical components perform these
tasks.
Following is the listing of RTRM failure indication causes.
System Failure
Check the voltage between RTRM terminals 6 and 9 on J6,
it should read approximately 32 Vdc. If no voltage is
present, a System failure has occurred. Refer to
"Microprocessor Control," p. 45
troubleshooting procedure.
Cooling Failure
• CLP1 has opened during the 3 minute minimum "on
time" during four consecutive compressor starts,
check CLP1 by testing voltage between the J1-8 and
J3-2 terminals on the RTRM and ground. If 24 Vac is
present, the CLP has not tripped. If no voltage is
present, CLP has tripped.
System Failure
Measure the voltage between terminals J6-9 and J6-6.
Normal Operation = approximately 32 Vdc
System Failure = less than 1 Vdc, approximately 0.75 Vdc
Cool Failure
Measure the voltage between terminals J6-8 and J6-6.
Cool Operating = approximately 32 Vdc
Cool Off = less than 1 Vdc, approximately 0.75 Vdc
Cooling Failure = voltage alternates between 32 Vdc and
0.75 Vdc
RRU-SVX02F-EN
Step 4 in
for the recommended
Alarms and Troubleshooting
47