Modine Manufacturing SSD Installation And Service Manual page 37

TROUBLESHOOTING
Troubleshooting – Indoor Unit (cont.)
Trouble
D. No Cooling (cont.)
E. Water Leaking From
Unit
(see also"Condensate
High Level")
F. Condensate High
Level
(microprocessor
units: LED's will
flash)
G. Coil Freeze
Possible Cause
6. Indoor coil temperature too low.
7. Sensor failure. (Microprocessor units only -
Digit 8 = M)
8. Outdoor unit tripped.
9. Faulty valve actuator. (Chilled water units only –
Digit 2,3=CW)
1. Condensate plug loose or missing.
2. Unit installed unevenly.
3. Condensate drain piping installed incorrectly.
4. Blocked/kinked condensate pipe.
5. Condensate pump blocked or failed.
6. Float switch failure.
1. Maximum pump lift exceeded.
2. Blocked/kinked condensate pipe.
3. Condensate pump blocked or failed.
4. Coil freeze up.
1. Cooling coil freeze protection thermostat tripped.
(Auto-reset when freeze cleared)
2. Dirty or blocked air filter.
3. System head pressure set too low.
4. Loss of refrigerant.
6. Check refrigerant charge by measuring operating
pressures. Check filters condition. (See page 32 for
filter removal and cleaning instructions)
7. If any of the sensors are faulty the microprocessor will
disable the cooling operation.
8. Check outdoor unit - refer to outdoor unit troubleshooting
section.
9. Check cooling signal present at actuator. Check actuator
by manually opening the valve. Replace actuator if
necessary.
1. Check that the rubber condensate plug is securely fitted
to the underside of the unit's polystyrene drip tray. On
some models this is located underneath the fascia
support rails on the pump side of the unit.
2. With fascia removed, ensure that the unit chassis is level
(at the face) both front to back and left to right, to ensure
correct condensate flow.
3. Check that the site installed condensate gravity drain
slopes 'downhill' away from the unit. (See page 9 of
this manual for condensate piping installation guide)
4. Check condensate piping for blocks/kinks, clear as
necessary. Check for a water tight connection between
the condensate outlet and the site installed condensate
gravity drain.
5. Clear any blockages and ensure that power is being
applied to the pump. If the pump still does not run,
replace the pump.
6. Check that the float switch operates correctly and is
properly positioned. Float switch is normally closed,
opens on rise of water level.
1. Check that the condensate pump head is no greater than
30". (See page 9 of this manual for condensate piping
installation guide)
2. See section "E. Water Leaking From Unit
(see also"Condensate
High Level")"
3. See section "E. Water Leaking From Unit
(see also"Condensate
High Level")"
4. A coil freeze condition may have caused excessive
condensate to collect in the drip tray. See section "G. Coil
Freeze".
1. Freeze stat is normally closed, opens during freeze.
Where fitted, the stat will disable the cooling action
(sometimes the entire system) during coil freeze
conditions. Use the unit's wiring schematic to investigate.
2. Clean / replace filters as necessary. (See page 32 for
filter removal and cleaning instructions)
3. Check condensing pressure, installation of low ambient
kit may be required.
4. Check system for refrigerant leaks and repair before
re-charging.
8-504.11
Possible Remedy
37