Rtrm Failure Modes; Airflow Troubleshooting - Trane Horizon OAB Series Installation, Operation And Maintenance Manual

Table 17. TOAU UC600 troubleshooting (continued)
Trouble Possible Cause
High fire gas manifold pressure too high
Supply fan speed too low
Dirty or clogged filters
Unit Trips Heater
High Limit
Restricted discharge air duct
Temperature of air entering heater too high
Defective high limit
Protonode Not
Change Baud rate on UC600 to 38,400
Communicating

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 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.
AVERTISSEMENT
Composants électriques sous tension!
Le non-respect de toutes les consignes de sécurité lors
de la manipulation de composants électriques sous
tension peut entraîner des blessures graves, voire
mortelles. S'il est nécessaire de travailler avec des
composants électriques sous tension, demandez à un
électricien qualifié et agréé ou à une autre personne
ayant la formation nécessaire pour manipuler des
composants électriques sous tension d'exécuter ces
tâches.
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. 51
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
OAU-SVX005C-EN
Step 4 in
for the recommended
Alarms and Troubleshooting
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

Airflow Troubleshooting

Table 18. Airflow troubleshooting
Profile Opening Width (in.)
Airflow 6-in. Burner
500 6.5
750 7.5
1000 9
1250 10
1500 11-1/4
1750 12-1/2
2000 13-3/4
2250 14-3/4
2500 16
2750 17-1/4
3000 18-1/2
3250 19-3/4
3500 21
3750 22
4000 23-1/4
4250 24-1/2
4500 25-3/4
4750 27
5000
5250
5500
5750
6000
6250
6500
6750
7000
7250
7500
12-in. Burner 18-in. Burner
14
15
15-3/4 14-1/4
16-3/4 15
17-1/2 15-1/2
18-1/4 16-1/4
19-1/4 17
20 17-1/2
21 18-1/4
21-3/4 18-3/4
22-1/2 19-1/2
23-1/2 20-1/4
24-1/4 20-3/4
25 21-1/2
26 22
26-3/4 22-3/4
27-3/4 23-1/2
28-1/2 24
29-1/4 24-3/4
30-1/4 25-1/4
31 26
53