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6–5
T-359
6.11 ELECTRONIC EXPANSION VALVE MALFUNCTION
Low suction pressure
Incorrect software and/or controller configuration
Check
Failed suction pressure transducer (SPT),
or evaporator pressure transducer (EPT)
Replace
Suction service valve partially closed
Open
Filter drier partially plugged
Low refrigerant charge
No evaporator air flow or restricted air flow
Excessive frost on evaporator coil
Evaporator fan(s) rotating backwards
EEV control malfunction
Failed digital unloader valve (DUV)
Replace
Loose or insufficiently clamped sensor
Replace
High suction pressure
with low superheat
Foreign material in valve
Failed suction pressure transducer (SPT),
or evaporator pressure transducer (EPT)
Replace
EEV control malfunction
Replace
Improperly seated powerhead
Ensure power
head is locked
and in place
Liquid slugging in
compressor
Failed suction pressure transducer (SPT),
or evaporator pressure transducer (EPT)
Replace
Failed EEV
Replace
6.12 COMPRESSOR OPERATING IN REVERSE
NOTE
The compressor may start in reverse for up to 10 seconds to determine correct phase rotation if
required for phase detection.
CAUTION
!
Allowing the scroll compressor to operate in reverse for more than two minutes will result in
internal compressor damage. Turn the start-stop switch OFF immediately.
Electrical
Incorrect wiring of compressor
Check
Incorrect wiring of compressor contactor(s)
Incorrect wiring of current sensor
CONDITION
POSSIBLE CAUSE
REMEDY/
REFERENCE
SECTION
Summary of Contents for 69NT40-561-019
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Page 127: ...8 3 T 359 Figure 8 2 SCHEMATIC DIAGRAM Evergreen Unit Configuration ...
Page 128: ...T 359 8 4 Figure 8 3 UNIT WIRING DIAGRAM Evergreen Unit Configuration Sheet 1 of 2 ...
Page 129: ...8 5 T 359 Figure 8 4 UNIT WIRING DIAGRAM Evergreen Unit Configuration Sheet 2 of 2 ...
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