50
TROUBLESHOOTING CHART
System
Operating
Pressures
POSSIBLE CAUSE
DOTS IN ANALYSIS
GUIDE INDICATE
"POSSIBLE CAUSE"
Compressor will not start - fan runs
Comp. and Cond. 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/htg
Too cool and then too warm
Not cool enough on warm days
Certain areas too cool, others too warm
System runs - blows cold air in heating
Unit will not terminate defrost
See Service Procedure Ref.
• • •
Inspect Fuse Size & Type S-1
• • •
Inspect Connection - Tighten S-2, S-3
• • • • • •
Test Circuits With Ohmmeter S-2, S-3
• •
Test Continuity of Overload S-17A
• • • •
Test Continuity of Thermostat & Wiring S-3
• •
Check Control Circuit w ith Voltmeter S-4
Shorted or Open Capacitor
• • • • •
Test Capacitor S-15
Internal Compressor Overload Open
•
♦
Test Continuity of Overload S-17A
Shorted or Grounded Compressor
• •
Test Motor Windings S-17B
• • •
♦
Use Test Cord S-17D
Faulty Compressor Contactor
• • •
Test Continuity of Coil & Contacts S-7, S-8
•
Test Continuity of Coil And Contacts S-7
•
Test Control Circuit w ith Voltmeter S-4
• •
♦
Repair or Replace S-16
Shorted or Grounded Fan Motor
• •
Test Motor Windings S-16
Improper Cooling Anticipator
• •
Check Resistance of Anticipator S-3B
• •
♦
• •
Test For Leaks, Add Refrigerant S-101,103
• • • • •
Remove Restriction, Replace Restricted Part S-112
Open Element or Limit on Elec. Heater
♦ ♦
Test Heater Element and Controls S-26,S-27
• • • •
♦
Inspect Filter-Clean or Replace
• • • •
♦
Inspect Coil - Clean
Not enough air across Indoor Coil
• • • •
♦
Check Blow er Speed, Duct Static Press, Filter S-200
Too much air across Indoor Coil
♦
•
Reduce Blow er Speed S-200
Overcharge of Refrigerant
• • •
♦
• •
Recover Part of Charge S-113
• • •
♦
•
Inspect Coil - Clean
• •
♦
•
Recover Charge, Evacuate, Recharge S-114
Recirculation of Condensing Air
• • •
Remove Obstruction to Air Flow
Infiltration of Outdoor Air
• • •
Check Window s, Doors, Vent Fans, Etc.
Improperly Located Thermostat
• •
Readjust Air Volume Dampers
• •
Ref igure Cooling Load
•
♦
Replace Compressor S-115
• • • •
Test Compressor Efficiency S-104
•
♦
• •
Test Compressor Efficiency S-104
Wrong Type Expansion Valve
• • • • • •
♦
Replace Valve S-110
Expansion Device Restricted
• • • • • • •
Remove Restriction or Replace Expansion Device S-110
Oversized Expansion Valve
Undersized Expansion Valve
Expansion Valve Bulb Loose
• •
Tighten Bulb Bracket S-105
Inoperative Expansion Valve
• • •
Check Valve Operation S-110
•
♦ ♦ ♦ ♦ ♦ ♦
Replace Valve or Solenoid S-21, 122
•
♦ ♦ ♦ ♦ ♦ ♦
Test Control S-24
Faulty Def rost Thermostat
♦ ♦ ♦ ♦ ♦ ♦ ♦
Test Defrost Thermostat S-25
Flow rator Not Seating Properly
• • •
Check Flow rator & Seat or Replace Flow rator S-111
•
Cooling or Heating Cycle (Heat Pump) ♦
COOLING/HP ANALYSIS CHART
Unsatisfactory
Cooling/Heating
He ating Cycle Only (Heat Pum p)