140 RT-SVX34C-EN
Diagnostics
F. CPR1 and ODM1 will not
operate.
1. No power to CC1 coil. Possible
Cool Failure
1. Check wiring, terminals and applicable controls
(CCB1, HPC1, TDL1, WTL1, LPC1)
2. CC1 coil defective. Cool Failure
Indicated.
2. Check CC1 coil. If open or shorted, replace CC1.
3. CC1 contacts defective.
3. If 24 VAC is present at CC1coil, verify contact
closure.
4. RTRM is defective.
4. If 24 VAC is not present at CC1 coil, reset the Cool
Failure by cycling the main power disconnect switch.
Verify system MODE is set for cooling operation. If no
controls have opened, and CC1 will not close, replace
RTRM.
5. LPC1 has tripped
5. Leak check, repair, evacuate, and recharge as
necessary. Check LPC1 operation.
G. ODM 3 and/or 4 will not
cycle.
1. OAS has failed.
1. Perform OAS Resistance/Temperature check.
Replace if necessary.
2. ODM3 and/or 4 capacitor has
failed.
2. Check ODM capacitor, replace if necessary.
3. Wiring, terminal, or CC2
contactor failure.
3. Check wires, terminals, and CC2. Repair or replace
if necessary.
4. ODM3 and/or 4 has failed. 4. Check ODM, replace if necessary.
5. RTRM is defective. 5. Replace RTRM module
6. ODF20 has failed.
6. Check for proper voltage and contact closure.
ODF20 relay has a 24 VAC holding coil. If voltage is
present, replace relay.
H. CPR2 and 3 (if applicable)
will not operate.
1. No power to CC2 and/or 3 coil.
Cool Failure Possible.
1. Check wiring, terminals and applicable controls
(CCB2, CCB3, HPC2, LPC2, WTL2, WTL3, TDL2 &
TDL3)
2. CC2 and/or 3 coil defective.
Cool Failure Indicated.
2. Verify integrity of CC2 and/or 3 coil windings. If
open or shorted replace CC2 and/or CC3.
3. CC2 and/or 3 contacts
defective.
3. If 24 VAC is present at CC2 and/or 3 coil, replace
relay.
4. RTRM is defective.
4. 24 VAC is not present at CC2 and/or 3 coil. Reset
the Cool Failure by cycling the service disconnect.
Place the unit into Cool Stage 2 Mode, step 4 for
constant Volume or step 6 for variable air volume, to
insure CPR2 and 3 Compressor operation. Check input
devices in #1 & #2 above, if no controls have opened,
and CC2 and/or 3 will not close, replace RTRM.
5. DLT2 and DLT3 has tripped.
4. Check for leaks, Open wire connections, Lose quick
connect terminals, TDL2 and TDL3 resistance check.
I. Indoor motor (IDM) will not
operate
1. IDM has failed. 1. Check IDM, replace if necessary.
2. Wiring, terminal, or contactor
failure.
2. Check wiring, terminals and F contactor. Repair or
replace wiring, terminals, or fan contactor F.
3. ZSM is defective.
3. Place unit in test mode. If the fan operates in the
test mode, test the ZSM using the appropriate test
procedures.
4. RTRM is defective.
4. Check the RTRM fan output. Locate P2-1 on the
RTRM. Measure voltage to ground. If 24 VAC is not
present on a call for fan, replace the RTRM.
5. Supply Fan Proving
(FFS)switch has opened.
5. Check FFS and belts, repair or replace if necessary.
Table 77. Troubleshooting (continued)
SYMPTOM PROBABLE CAUSE RECOMMENDED ACTION
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