Compressor Operating Checks; Refrigeration Circuit Leak Test; Troubleshooting - Fujitsu Waterstage Comfort Series Maintenance Document

Split system single phase type
b Defrost ending conditions
With all models, defrosting stops if the exchanger
temperature is above 16 °C (100L model : 13°C) or if
the defrosting time is over 15 minutes)
Crankcase heater
When the outdoor exchanger temperature is below
-5°C and the heating mode has been stopped for 30
minutes, the compressor windings are powered and
maintain the compressor temperature
When operation has started and the temperature
becomes higher than -3°C, heating stops
3 2

Compressor Operating Checks

Using a multimeter set to mega ohm, check that the
resistance value across the windings is identical
irrespective of the phase (between U and V, V and W,
W and U) This value should be approx 1 Ohm
Check that resistance between each phase and the earth
is infinite. The result should be clear (you should not
see the displayed value increasing slowly up to a value
greater than the multimeter maximum rating)
3 3

Refrigeration Circuit Leak Test

The new regulation requires annual leak testing of
installations with a refrigerant charge higher than 2kg
Leak testing is to be performed with an approved detector
that has been appropriately calibrated
3 4

Troubleshooting

The heat pump is not operating at all (no illuminated
indicator):
• Are the power supply voltage and frequency normal?
• Is the connection to mains correct?
• Have all the connectors been properly inserted?
• Are the fuses on the outdoor unit still operating? If not,
change the bad fuse(s)
• Is the connection between the outdoor unit and the
Hydraulic Unit correct? Do you read 230V AC between
terminals 1 and 2 of the Hydraulic Unit terminal block?
• Do you read 230V AC at the transformer primary on the
Hydraulic Unit? If not, change the board
• Is there any voltage on the transformer secondary on
the Hydraulic Unit? If not, check the thermal fuse If the
fuse is good, the error comes from the board
If the defrost sensor is not iced up while the rest of the
exchanger is, then:
- Move the sensor between the exchanger blades
to a place where the exchanger is iced up
- If all these points have been checked, replace
the outdoor controller board
Maintenance document "1792 - EN"
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