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Troubleshooting Information
For detailed service information refer to the Remote Condensing Unit Service manual.
Complaint
Unsatisfactory
Cooling
POSSIBLE CAUSE
DOTS IN ANALYSIS
GUIDE INDICATE
"POSSIBLE CAUSE"
SYMPTOM
System will not start
Compressor will not start - fan runs
Compressor and Condenser Fan will not start
Evaporator fan will not start
Condenser fan will not start
Compressor runs - goes off on overload
Compressor cycles on overload
System runs continuously - little cooling
Too cool and then too warm
Not cool enough on warm days
Certain areas to cool others to warm
Compressor is noisy
Low suction pressure
Low head pressure
High suction pressure
High head pressure
Test Method
Remedy
Power Failure
•
Test Volta
g
e
Blown Fuse
•••
Impact Fuse Size & Type
Loose Connection
• •••
Ins
p
ect Connection - Ti
g
hten
Shorted or Broken Wires
••••••
Test Circuits with Ohmmeter
Open Overload
••
Test Continuit
y
of Overloads
Faulty Thermostat
••• •
Test Continuit
y
of Thermostat and Wirin
g
Faulty Transformer
••
Check Control Circuit with Voltmeter
Shorted or Open Capacitor
• •••
Test Ca
p
acitor
Internal Com
p
ressor Overload O
p
en
•
Test Continuit
y
of Overload
Shorted or Grounded Compressor
••
Test Motor Windin
g
s
Compressor Stuck
••
Use Test Cord
Faulty Compressor Contactor
••• •
Test Continuit
y
of Coil and Contacts
Faulty Fan Relay
•
Test Continuit
y
of Coil and Contacts
Open Control Circuit Test Control Circuit with Voltmeter
Low Voltage
•••
Test Volta
g
e
Faulty Evaporator Fan Motor
••
Re
p
air or Re
p
lace
Shorted or Grounded Fan Motor
•• •
Test Motor Windin
g
s
Improper Cooling Anticipator
•
Check Resistance of Antici
p
ator
Shortage or Refrigerant
•• ••
Test For Leaks, Add Refrigerant
Restricted Liquid Line
•• ••
Re
p
lace Restricted Part
Undersized Liquid Line
•• •
Replace Line
Undersized Suction Line
•
Re
p
lace Line
Not Enough Air across Indoor Coil
••••
Speed Blower, Check Duct Static Pressure
Too Much Air across Indoor Coil
•
Reduce Blower S
p
eed
Overcharge of Refrigerant
•• • ••
Recover Part of Charge
Noncondensibles
•• •
Recover Char
g
e, Evacuate, Rechar
g
e
Recirculation of Condensing Air
•• •
Remove Obstruction to Air Flow
Infiltration of Outdoor Air
•••
Check Windows, Doors, Vent Fans, Etc.
Improperly Located Thermostat
•
Relocate Thermostat
Air Flow Unbalanced
••
Read
j
ust Air Volume Dam
p
ers
System Undersized
••
Refigure Cooling Load
Broken Internal Parts
•
Re
p
lace Com
p
ressor
Broken Valves
•
Test Compressor Efficiency
Inefficient Compressor
•••
Test Com
p
ressor Efficienc
y
High Pressure Control Open
•
Reset and Test Control
Unbalanced Power, 3PH
•••
Test Volta
g
e
Wrong Type Expansion Valve
•• •
Replace Valve
Expansion Valve Restricted
••• • ••
Re
p
lace Valve
Oversized Expansion Valve
••
Replace Valve
Undersized Expansion Valve
••• • •
Re
p
lace Valve
Expansion Valve Bulb Loose
••
Ti
g
hten Bulb Bracket
Inoperative Expansion Valve
•• •
Check Valve O
p
eration
Loose Hold-down Bolts
•
Tighten Bolts
No Cooling
System
Operating
Pressures
NOTICE
UNITS WITH ROTARY OR RECIPROCATING COMPRESSORS AND NON-BLEED
TXV’S REQUIRE A HARD START KIT.