SYMPTOMS
POSSIBLE CAUSE
CHECK OR REMEDIES
Short cycling of compressor (cont.)
Low charge
Check system charge
Low evaporator air flow
Dirty coil
Dirty filter
Duct too small or restricted
Faulty run capacitor
Replace
Faulty internal overload
Replace compressor
Faulty Compressor Valves
Fast equalization/
Replace compressor and examine
Low pressure difference
system to locate reason
ELECTRICAL
SYMPTOMS
POSSIBLE CAUSE
CHECK OR REMEDIES
Voltage present on load side
Compressor start components
Check start capacitor
of compressor contactor and
compressor won’t run
Check potential relay
Run capacitor
Check with ohmmeter
Internal overload
Allow time to reset
Compressor windings
Check for correct ohms
Voltage present on line side of
Thermostat
Check for control voltage to com-
pressor contactor only
contactor coil
Compressor control circuit
High pressure switch
Low pressure switch
Ambient thermostat
Solid state protection control or
internal thermal sensors
Compressor timed off/on
control or interlock
No voltage on line side
Blown fuses or tripped circuit breaker
Check for short in wiring or unit
of compressor contactor
Improper wiring
Re-check wiring diagram
Improper voltage
High voltage
Wrong unit
Power supply problem
Low voltage
Wrong unit
Power supply problem
Wiring undersized
Loose connections
Single Phasing (3 phase)
Check incoming power and fusing
CONTAMINATION
SYMPTOMS
POSSIBLE CAUSE
CHECK OR REMEDIES
Moisture
Poor evacuation on installation
In each case, the cure is the same.
or during service
Recover refrigerant. Add filter drier,
evacuate and re-charge
High head pressure
Non-condensibles air
Unusual head and suction readings
Wrong refrigerant
Foreign Matter-
copper filings
Copper tubing cuttings
Copper oxide
Dirty copper piping
Welding scale
Nitrogen not used
Soldering flux
Adding flux before seating
copper part way
Excess soft solder
Wrong solder material
47
Содержание PRL-series
Страница 52: ...FIGURE 11 WIRING DIAGRAM FOR 2 3 4 TON 19 0 WIRING DIAGRAMS 52 ...
Страница 53: ...FIGURE 12 WIRING DIAGRAM FOR 5 TON 53 ...
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Страница 56: ...56 CM 1108 ...