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7
Troubleshooting
Flash
code
Alarm conditions
Possible failure reasons
Troubleshooting measures
1
Insufficient
oil
pressure
Alert: Appears when the differential
oil pressure is less than 0.48
– 0.62
bar for 4 seconds.
Lockout:
Appears
when
the
differential oil pressure is less than
0.48
– 0.62 bar for 2 minutes
continuous
or
intermittent
but
determined to be unsafe.
Loose wiring connections
between CoreSense module
and oil sensor.
Faulty oil sensor (missing O-
ring
or
clogged
sensor
screen).
Faulty oil pump.
Clogged strainer screen or
worn bearings.
Check the oil level present in the sight glass. If the oil is not present, resolve
reservoir oil supply problem or oil level control setting issues.
Check that the harness is fully engaged to the sensor.
Measure oil pump differential pressure. If less than 0.48 to 0.62 bar, inspect for
clogged oil screen, faulty oil pump, liquid floodback or worn bearings.
If good oil pressure exists, measure resistance across the oil sensor while the
compressor runs. If the sensor resistance is "open" inspect for clogged sensor
screen or missing O-ring.
If sensor resistance is "closed", temporarily jumper across the harness connector
pins (do not damage the pins!) while the compressor runs. If the oil warning does
not go away, check harness connector engagement at the module circuit board.
2
Motor overheat
Trip: Appears when the motor is
overheated.
Motor rotor is mechanically
seized.
Open circuit in harness.
Connector pin not engaging
at connector on control
module.
Faulty CoreSense module.
In case of trip alarm, allow the motor to cool down for a minimum of 2 minutes (it
may take longer) and the compressor will start automatically.
If resistance is low, inspect for loose terminal strip connections, harness
connection failure at circuit board, open harness circuit or high motor temp due
to return gas temperature, motor voltage or load condition.
3
Discharge temp
protection
Alert: Appears when the discharge
temperature sensor is defective or
disconnected.
Trip/Lockout: Appears when the
discharge temperature is > 154°C for
2 seconds.
Open
discharge
probe
(faulty).
The probe connection has
not been made to the
harness connector.
The connector is not plugged
into the CoreSense circuit
board.
The discharge temperature
has exceeded the maximum
limit 154°C.
Blocked condenser.
Possible loss of refrigerant.
If there is an alert, check proper probe connection to the harness and proper
harness connection into the circuit board.
If there is an alert, unplug the discharge temp probe and check if the resistance
of the probe is as specified vs its approximate ambient temperature.
If the probe resistance is correct inspect the harness connector receptacle for
damage and apply NyoGel 760G connector lubricant.
Trip or Lockout: resolve system issues (high superheat, high head pressure),
inspect for mechanical damage that can lead to high temps (valve plate gasket,
suction or discharge valve failure).
