Troubleshooting - Daikin DCC Series Installation Instructions Manual

TROUBLESHOOTING

THE FOLLOWING INFORMATION IS FOR USE BY QUAL-
IFIED SERVICE AGENCY ONLY: OTHERS SHOULD NOT
ATTEMPT TO SERVICE THIS EQUIPMENT.
Common Causes of Unsatisfactory Operation of Heat Pump
on the Heating Cycle.
i a V
naDEquatE ir oLuME
When a heat pump is in the heating cycle, the indoor coil is
functioning as a condenser. The return air filter must always
be clean, and sufficient air volume must pass through the
indoor coil to prevent excessive discharge pressure, and
high pressure cut out.
o a r
utsiDE ir into Eturn
Do not introduce cold outside air into the return duct of a heat
pump installation. For units with 2-speed motors, do not allow
air entering the indoor coil to drop below 65° F. Air below
this temperature will cause low discharge pressure, thus low
suction pressure, and excessive defrost cycling resulting in
low heating output. It may also cause false defrosting.
u
nDErChargE
An undercharged heat pump on the heating cycle will cause
low discharge pressure resulting in low suction pressure and
frost accumulation on the outdoor coil.
P "t " s
oor ErMinating Ensor ContaCt
The unit's defrost terminating sensor must make good thermal
contact with the outdoor coil tubing. Poor contact may not
terminate the unit's defrost cycle quickly enough to prevent
the unit from cutting out on high discharge pressure.
t i C
hrough nDoor oiL
D
uCt
M r
aLfunCtioning EVErsing
1. Solenoid not energized - In order to determine if
the solenoid is energized, touch the nut that holds
the solenoid cover in place with a screwdriver. If the
nut magnetically holds the screwdriver, the solenoid
is energized and the unit is in the cooling cycle.
2. No voltage at unit's solenoid - Check unit voltage.
If no voltage, check wiring circuit.
3. Valve will not shift:
a. Undercharged - check for leaks;
b. Valve Body Damaged - Replace valve;
c. Unit Properly Charged - If it is on the heating cycle,
raise the discharge pressure by restricting airflow
through the indoor coil. If the valve does not shift,
tap it lightly on both ends with a screwdriver handle.
DO NOT TAP THE VALVE BODY. If the unit is on
the cooling cycle, raise the discharge pressure by
restricting airflow through the outdoor coil. If the
valve does not shift after the above attempts, cut
the unit off and wait until the discharge and suction
pressure equalize, and repeat above steps. If the
valve does not shift, replace it.
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V - t
aLVE his MaY BE DuE to
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