Rheem RA17 Series, Руководство по установке

Страница: 52 / 56

52
Diagnostics
DIAGNOSTICS
Service Analyzer Charts
ELECTRONIC EXPANSION VALVES (cont.)
SYMPTOM POSSIBLE CAUSE REMEDY
Valve feeds too much
refrigerant, with low
superheat, with low
superheat and
higher than normal
suction pressure.
EEV control dc circuit failed Verify 5Vdc to pressure transducer is present, if not,
replace EEV controller.
High superheat adjustment hange the superheat o set dip switches to increase
superheat.
Moisture causing valve to stick open. ecover refrigerant, replace lter-drier, evacuate
system, and recharge.
Dirt or foreign material causing valve to stick
open ecover refrigerant, replace lter-drier, remove
and purge with nitrogen, evacuate system, and recharge.
If EEV is completely clogged, use the EEV control to
open the , and purge with nitrogen, replace lter drier,
and recharge.
Oversized EEV Install correct EEV
Incorrect suction thermistor location Install suction thermistor with the provided stainless
steel strap and an additional zip tie at the 10:00 or 2:00
position on suction line, with insulation.
Low superheat adjustment hange the superheat o set dip switches to increase
superheat.
Incorrectly sensing vapor line temperature Verify suction thermistor resistance is correct and
properly attached and insulated to the vapor line.
Suction thermistor incorrectly calibrated Replace suctioon thermistor assembly.
Vapor pressure measured incorrectly. After verifying lack of connectivity, replace the pressure
transducer or harness.
If harness has a short, replace harness
If gauge pressure measurement and the converted
voltage readings at the control are di erent replace
pressure transducer
If gauge pressure measurement and the converted
voltage readings at the control are the same, replace
the control.
ompressor ood
back upon start-up
efrigerant drainage from 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 nsure air ow is equally distributed through evaporator.
Check for blocked distributor tubes.
ow load or air ow entering evaporator coil Ensure blower is moving proper air CFM.
emove orrect any air ow restriction.