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The switch that has been selected for detecting reverse
rotation is Carrier part number HK01CB001. This switch
opens the contacts when the pressure falls below 7 kPa. The
switch is a manual reset type that can be reset after the
pressure has once again risen above 70 kPa. It is critical
that the switch be a manual reset type to preclude the
compressor from short cycling in the reverse direction.
11.8 - Frequency variator maintenance
ATTENTION: Before any intervention at the frequency
variator, ensure that the disconnect/isolator switch is open
and that no voltage is present (reminder: the capacitor
discharge time is approximately 20 minutes).
Only a well qualified person is allowed to replace or
modify the components inside the frequency variator.
During periodic inspections, check the ventilation grilles at
the frequency variator door; ensure that they are not
pierced, damaged or obstructed.
Replace the fan, if a “replace fan” alert/warning is displayed
in the alarm list.
For any other alarm or problem at the frequency variator,
contact the Carrier service department.
The frequency variators in the 30XW-V/30XWHV units do
not require a dielectric test, even if they are replaced parts:
they are systematically checked before delivery. Otherwise
the filtering components installed in the frequency variator
can falsify the measurement and may even be damaged.
If it is necessary to test the insulation of a component (e.g.
compressor, cables) the frequency variator must be
disconnected at the power circuit.
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Equal pressure
11.9 - Service valve (option 92)
The unit can be equipped with optional service valves to
facilitate maintenance and repair operations.
If option 92 is ordered, each refrigerant circuit will be
supplied with shut-off valves on the compressor economiser,
discharge and suction lines.
ATTENTION: The compressor suction valve must be
used without pressure difference at the terminals. If there
is a pressure difference, leak-tightness at the valve may be
lost and the valve can even fail altogether.
