MAINTENANCE
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the assistance service.
VFDs equipped with units do not require an insulation test, even if
they are replaced; they are in fact checked systematically before
delivery. In addition, the filter components installed in the VFD can
distort the measurement and can also be damaged. If there is a
need to check the insulation of the components of the appliance
(fan motors and pumps, cables, etc.), the VFD must be disconnect-
ed from the power circuit.
4.7 Refrigerant volume
The unit must be started in cooling mode to find out if the unit load
is correct by checking the actual subcooling.
A small loss of refrigerant compared to the initial load will be evi-
dent in the cooling mode and will affect the subcooling value ob-
tained at the outlet of the air heat exchanger (condenser), but will
not be visible in heating mode.
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It is therefore not possible to optimize the refrigerant charge in
the heating mode after a leak. The unit will need to be started
in cooling mode to check if an additional load is required.
