Dometic MCS6 Notice D'utilisation page 29

MCS6, MCS12, MCS16
Problem
"HPF" (High Freon
Pressure) is
displayed.
"LAC" (Low AC
Voltage) is displayed.
"LPF" (Low Freon
Pressure) is
displayed.
"PLF" (Low Pump
Flow) is displayed.
EN
Possible Reason
High-pressure switch is open (in
cooling) due to improper sea-
water flow.
Strainer or intake may be
plugged, seacock may be closed.
High-pressure switch open (in
heating) due to improper airflow.
Supply voltage is too low.
Voltage is improperly calibrated.
Low-pressure switch is open due
to low seawater and/or low return
air temperatures.
Low pressure switch is open due
to loss of refrigerant.
Condenser coil is too hot.
Thermistor is damaged.
Damaged jack/socket on circuit
board.
Troubleshooting
Solution
Check seawater hose for kinks or
collapses.
Verify pump operation.
Check pump circuit breaker if
applicable.
Remove obstructions in return air
stream.
Clean air filter and grille.
Check for crushed or restricted
ducting (ducting must be as
straight, smooth and taut as
possible).
If problem persists,
– reprogram Low Fan Speed
Limit for maximum value: Set
P-3 to "64"
– set the reverse fan speeds dur-
ing Heating Mode parameter
P-13 to "rEF", or manually set
fan speed to high
Verify power to unit with multi-
meter.
Verify that P-22 matches voltage
reading to unit with a multimeter.
Try restarting the air conditioning
unit, the optional low pressure
switch has a ten minute shut-
down time delay that may be in
affect.
Check air conditioning unit for
refrigerant oil leakage.
Call service technician.
Verify that unit is getting water
flow, and that condenser is not
fouled.
Unplug water sensor if installed.
Try another if it is available.
Visually check to see that pins
inside socket are not bent or cor-
roded.
Repair or replace circuit board if
needed.
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