Maintenance Diagnostic - Lennox eNeRGy Series Installation, Operating And Maintenance

MAINTENANCE DIAGNOSTIC

REFRIGERATION
MAINTENANCE DIAGNOSTIC
FAULT
LP FAULT
eNeRGy-IOM-2020.11-EN
POSSIBLE CAUSE AND SYMPTOMS
Refrigerant charge too low
In Heat Pump Mode the temperature
difference between T outdoor and Tevap.
(Dew) is too high
5°C < Delta T < 10°C excellent
10°C < Delta T < 15°C acceptable
15°C < Delta T < 25°C too high
Refrigeration circuit blocked in distribution
Liquid line drier blocked. High temperature
difference
Electronic expansion valve problem
Low pressure shutdown
accumulation on the batteries
SOLUTION
Measure the superheat and sub-cooling Good
if 5°C<SC<10°C and
SC>10°C and SH too low
Check superheat adjustment and charge unit (a
leak check must be carried out)
If too high check the coils are clean or check coil
internal pressure drop between the liquid line
and the suction line
Good if < 3bar
Too high > 3 bar (coil blocked)
Stop the fan and create icing of the coil.
Check all circuits freeze evenly across the whole
surface of the coil
If some parts of the coil do not freeze this could
indicate a problem with the distribution
Change filter drier
Check the wiring
due to ice Check the defrost cycles. (cloud supervision
advised)
5°C<SH<10°C Bad if
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