Functional & Performance Troubleshooting - Carrier 50YFV Installation, Operation And Maintenance Instructions

R e s i d e n t i a l D i g i t a l P a c k a g e d U n i t s G T- P B S e r i e s - 6 0 H z P u r o n
R e v : 4 A p r i l , 1 4
Functional Troubleshooting
Fault
Main Power Problems
HP Fault Code 2
High Pressure
LP/LOC Fault-Code 3
Low Pressure/Loss of Charge
LT1 Fault - Code 4
Water Low Temperature
LT2 Fault - Code 5
Low Air Temperature
Condensate Fault-Code
High Condensate Level
Over/Under Voltage-Code 7
(Auto Resetting)
54
Htg Clg Possible Cause
X X Green status LED off
X Reduced or no water flow
in cooling
X
Water t emperature out of range in
cooling
Reduced or no air flow
X
in heating
Air t emperature out of range in
X
heating
X X Overcharged with refrigerant
X X
Bad HP switch
X Frozen water heat exchanger
X X Bad HPWS Switch
X X Insufficient charge
Compressor pump down at start-
X
up
Reduced or no water flow
X
in heating
X Inadequate anti-freeze level
Improper low temperature setting
X
(30°F vs 10°F)
X Water t emperature out of range
X X Bad thermistor
Reduced or no air flow
X
in cooling
X Air temperature out of range
Improper low temperature setting
X
(30°F vs 10°F)
X X Bad thermistor
X X Blocked drain
X X Improper trap
X Poor drainage
6
X Moisture on sensor
Plugged air filter
X X
X X Restricted return air flow
X X Under voltage
X X Over voltage
Solution
Check Line Voltage circuit breaker and disconnect
Check for line voltage between L1 and L2 on the contactor
Check for 24VAC between R and C on DXM
Check primary/secondary voltage on transformer
Check pump operation or valve operation/setting
Check water flow adjust to proper flow rate
Bring water temp within design parameters
Check for dirty air filter and clean or replace
Check fan motor operation and airflow restrictions
Dirty air coil- construction dust etc.
Too high of external static. Check static vs blower table
Bring return air temp within design parameters
Check superheat/subcooling vs typical operating condition
table
Check switch continuity and operation - Replace
Thaw heat exchanger
Replace HPWS Switch
Check for refrigerant leaks
Check charge and start-up water flow
Check pump operation or water valve operation/setting
Plugged strainer or filter - clean or replace
Check water flow adjust to proper flow rate
Check antifreeze density with hydrometer
Clip LT1 jumper for antifreeze (10°F) use
Bring water temp within design parameters
Check temp and impedance correlation per chart
Check for dirty air filter and clean or replace
Check fan motor operation and airflow restrictions
Too high of external static - check static vs blower table
Too much cold vent air - bring entering air temp within
design parameters
Normal airside applications will require 30°F only
Check temp and impedance correlation per chart
Check for blockage and clean drain
Check trap dimensions and location ahead of vent
Check for piping slope away from unit
Check slope of unit toward outlet
Poor venting - check vent location
Check for moisture shorting to air coil
Replace air filter
Find and eliminate rectriction - increase return duct
and/or grille size
Check power supply and 24VAC voltage before and during
operation
Check power supply wire size
Check compressor starting. Need hard start kit?
Check 24VAC and unit transformer tap for correct power
supply voltage
Check power supply voltage and 24VAC before and during
operation.
Check 24VAC and unit transformer tap for correct power
supply voltage
®