48
DIAGNOSTICS
Service Analyzer Charts
THERMOSTATIC EXPANSION VALVES (cont.)
SYMPTOM
POSSIBLE CAUSE
REMEDY
Compressor
fl
ood
back upon start-up
Refrigerant drainage from
fl
ooded evaporator
Install trap riser to the top of the evaporator coil.
Inoperable crankcase heater or crankcase heater
needed
Replace or add crankcase heater.
Any of the causes listed under symptoms of
Electrical problems on page 45
Any of the solutions listed under solutions of Electrical
problems on page 45
Superheat is low to
normal with low
suction pressure
Unequal evaporator circuit loading
Ensure air
fl
ow is equally distributed through evaporator.
Check for blocked distributor tubes.
Low load or air
fl
ow entering evaporator coil
Ensure blower is moving proper air CFM.
Remove/Correct any air
fl
ow restriction.
Superheat and
suction pressure
fl
uctuate (valve is
hunting)
Expansion valve is oversized
Install correct TEV.
Sensing bulb is a
ff
ected by liquid refrigerant or
refrigerant oil
fl
owing through suction line
Relocate sensing bulb in another position around the
circumference of the suction line.
Unequal refrigerant
fl
ow through evaporator
circuits
Ensure sensing bulb is located properly.
Check for blocked distributor tubes.
Moisture freezing and partially blocking TEV
Recover refrigerant, change
fi
lter-drier, evacuate system,
and recharge.
Valve does not
regulate at all
External equalizer line not connected or line
plugged
Connect equalizer line in proper location, or remove any
blockage.
Sensing bulb lost its operating charge
Replace TEV.
Valve body damaged during soldering or by
improper installation
Replace TEV.
Diagnostics
Summary of Contents for RP13
Page 50: ...50 FOR SINGLE PHASE WITH PSC FAN MOTORS WIRING DIAGRAMS Wiring Diagrams...
Page 51: ...51 Wiring Diagrams WIRING DIAGRAMS 3 PHASE 208 230V MODELS...
Page 52: ...52 Wiring Diagrams WIRING DIAGRAMS FOR 3 PHASE 460 575V...
Page 54: ...54...
Page 55: ...55...
Page 56: ...56 CM 0815...
