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Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Catalog No. 04-53500144-01
Printed in U.S.A.
Form 50PS-6SI
Pg 62
8-22
Replaces: 50PS-5SI
© 2022 Carrier
No fan operation
(PSC motor)
X
X
Fan relay
energized
Faulty motor
Check supply voltage from the fan relay to the motor. Check
that all motor wires are secure. With power off spin the motor
shaft - noise, resistance or uneven motion can be signs of
motor failure.
Fan relay not
energized
No fan operation signal
Check for 24 VAC across the fan relay coil. Check all wiring
connections.
Bad fan relay
If the relay coil is energized but the relay does not pull in,
check the resistance across the relay coil - an open circuit is
an indicator of a faulty relay.
No fan operation
(constant torque
motor)
X
X
No fan operation signal
Check for 24 VAC between "G" and "C". Check all wiring
connections.
Loose wiring
Check all wiring connections at motor and control box.
Faulty motor
Check supply voltage to the motor. Check that all motor wires
are secure. With power off spin the motor shaft - noise,
resistance or uneven motion can be signs of motor failure.
No fan operation
(constant airflow
motor)
X
X
No fan operation signal
Check for 24 VAC between "G" and "C". Check all wiring
connections. Make sure that the thermostat connection plug is
securely connected.
Loose wiring
Check all wiring connections at motor and control box. Check
that power and control harnesses are securely connected.
Interface board problems
Make sure that the interface board is not damged and that all
DIP switches are in the proper configuration (refer to the
blower performance tables).
Faulty motor
Check supply voltage to the motor. Check that all motor wires
are secure. Move the "TEST" DIP switch to "ON" and the
other switches to "OFF" on the "ADJUST" switch block on the
interface board - the motor should run at 70% torque when
"G" is called. With power off spin the motor shaft - noise,
resistance or uneven motion can be signs of motor failure.
Unit not shifting
into cooling
X
Reversing valve
solenoid energized Faulty solenoid
Check that the reversing valve solenoid is receiving 24 VAC. If
so, check the resistance of the solenoid - an open circuit may
indicate a burned out solenoid.
Reversing valve
solenoid not
energized
Miswired/faulty
thermostat
Check that the reversing valve theromstat wire is connected
to the "O" terminal of the thermostat. Check for a contact
closure between "O" and "R".
Loose wire on "O"
terminal
Check that the wires from the thermostat to the unit are
securely connected and that the wires from the electrical box
to the reversing valve are connected.
Excessively cold
supply air
temperature in
cooling or
excessively hot
supply air
temperature in
heating
X
X
Reduced airflow
Dirty Filter
Replace filter.
Fan speed too low
Consult blower performance table and increase fan speed if
possible.
Excessive duct pressure drop
Consult blower performance table and increase fan speed if
possible.
Excessively warm
supply air
temperature in
cooling and/or
excessively cool air
in heating
X
X
Airflow too high
Fan speed setting too high
Consult blower performance table and reduce fan speed if
possible.
High or low water
temperature
Inlet water temperature out of
range
Check unit capacity vs. water temperature.
Air leakage
Leaky ductwork
Inspect ductwork.
Loss of refrigeration
capacity
Low refrigerant
Check refrigerant pressures with gage set.
High humidity
X
Airflow too high
Fan speed setting too
high
Consult blower performance table and reduce fan speed if
possible.
Loss of refrigeration
capacity
Low refrigerant
Check refrigerant pressures with gage set.
Short cycling
Unit oversized
Check unit performance against building load calculations.
Poor thermostat location
Make sure that thermostat is not located by a supply- air duct.
Objectionable noise
levels
X
X
Air noise
Poor ductwork/grille design
Ensure ductwork and grilles are properly sized for unit airflow.
Fan speed setting too high
Consult blower performance table and reduce fan speed if
possible.
Structure Bourne
noise
Unit not mounted on full vibration
pad
Mount unit on a vibration pad.
Unit not connected with flexible
conduit, water lines and/or
ductwork
Install unit in accordance with instructions.
Unit cabinet touching wall or other
building component
Adjust unit location to avoid unit touching structure.
X
Compressor noise
High water temperature or low
water flow rate elevating head
pressure
Increase water flow rate and/or reduce water temperature if
possible.
Scaled or fouled water coil
elevating heat pressure
Clean/descale water coil.
X
Low airflow elevating head
pressure
Check filter.
Increase fan speed.
X
X
Water hammer
Fast closing valves installed
Change valves to slow-close type.
Table 20 —
Troubleshooting (cont)
FAULT
COOLING HEATING
CHECK
POSSIBLE CAUSE
SOLUTION
Summary of Contents for AQUAZONE 50PSH
Page 17: ...17 Fig 15 PSC Motor Single Phase Single Stage WSHP Open Control ...
Page 20: ...20 Fig 18 Constant Torque Motor Single Phase Single Stage WSHP Open Control ...
Page 23: ...23 Fig 21 Constant Airflow Single Phase WSHP Open ...
Page 26: ...26 Fig 24 PSC Motor Three Phase Single Stage WSHP Open ...
Page 29: ...29 Fig 27 Constant Torque Motor Three Phase Single Stage WSHP Open ...
Page 32: ...32 Fig 30 Constant Airflow Motor Three Phase Single Stage WSHP Open ...