Modine Manufacturing MPR30 - Troubleshooting Guide (Table 59.1)

59MCP15-500.9
Table 59.1 - Troubleshooting (Continued)
SERVICE & TROUBLESHOOTING - CONTINUED
Trouble Possible Cause Possible Remedy
F. Compressor(s) Do
Not Operate
1. See Problems “A” and “B” 1. See Problems “A” and “B”
2. Controls are in Unoccupied mode 2. Wait for Occupied mode or override
3. Ambient lockout 3. Check and wait or override
4. Low pressure lockout 4. Check and wait or override
5. High pressure lockout 5. Check and wait or override
6. Inter-stage delay 6. Check and wait or override
7. Airow proving switch not closing 7. Check and correct
8. Thermostat not calling for cooling 8. Check and wait or override
9. Drain pan oat switch open
9. Check switch, check drain line (pan, trap, piping) for proper
drainage, and verify trap is primed with water
G. Compressor(s) Do
Not Cycle O󰀨
1. Supply air temperature not satised 1. Compressors will remain on until the supply air setpoint is
satised
H. Dampers Do Not
Operate
1. See Problem “A” 1. See Problem “A”
2. Failed damper motor(s) 2. Check and replace
3. Loose wiring to damper motor(s) 3. Check and tighten
4. Controls are in Unoccupied mode 4. Wait for Occupied mode or override
5. Ambient lockout 5. Check and wait or override
I. Electric Heat Not
Functioning
1. See Problem “A” 1. See Problem “A”
2. See Problem “D” 2. See Problem “D”
3. Thermostat not calling for heat 3. Check and wait or override
4. Limit switches are open 4. Check and correct
5. Overload relay is tripped 5. Check and correct
6. Failed heat modules 6. Check and replace
J. Gas Heat Not
Functioning Properly
1. See Problem “A” 1. See Problem “A”
2. See Problem “D” 2. See Problem “D”
3. Thermostat not calling for heat 3. Check and wait or override
4. Limit switches are open 4. Check and correct
5. Main gas supply not turned on 5. Check and correct
6. Air in gas line 6. Purge per instructions
7. Loose wiring to ignition controls or gas valves 7. Check and tighten
8. Failed ignition controller or gas valve 8. Check and replace
9. Failed ame sensor 9. Check and replace
10. Improper supply air temperature sensor installation 10. Check and correct
11. Flame rollout or ashback 11a. Main pressure too high (correct to 14” W.C. max)
11b. Orice too large (verify they match the serial plate)
11c. Manifold pressure too low (reset)
12. Not enough heat 12a. Unit cycling on high limit (check airow)
12b. Main pressure too low (must be 6” W.C. minimum for
Natural Gas or 11” W.C. for Propane (LP) Gas)
12c. Unit undersized for conditions
12d. Improper supply air temperature sensor installation
13. Too much heat 13a. Manifold pressure too high (correct to 3.5” W.C.)
13b. Defective or improperly wired controls
14. Clogged condensate drain line (condensing or hybrid
condensing heat option only)
14. Check condensate drain line, clear as needed