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5.3.
Voltage Phase Check
5.3.1. Evaporator Phase Check
Prior to fully charging a unit, the correct voltage phasing should be checked on the indoor
evaporator. EC plug fans are not dependent on the input power phasing and will always operate
in the proper direction.
Before checking the fixed speed, scroll compressor voltage phasing make sure that its circuit
has been charged with 80% of its refrigerant capacity by following the steps in section
5.7.3 Water/Glycol-Cooled System
for initial charging.
5.3.2. Fixed Speed Scroll Compressor Phase Check
Since the fixed speed, scroll compressors are phase dependent, the easiest way to check proper
phasing is to check the rotation of the fixed speed scroll compressor (if available) on the
evaporator section of dual circuit units by momentarily energizing the COOL 2 (fixed speed
compressor) under the dap4 MENU I
– MANUAL CONTROL (Service Level). See dap4 IOM
instructions for details. As soon as the compressors comes on, observe the compressor
pressure difference for a few seconds and then turn the Cool 2 OFF.
An out of phase fixed speed scroll compressor will draw relatively low amps and both suction
and discharge pressures will remain nearly equal. If necessary, reverse any two of the three
input line voltage wires at the line voltage field connection point to change the compressor
rotation.
Although fixed speed scroll compressors are phase dependent, units shipped from the factory
are run tested, ensuring the compressor rotation is consistent with evaporator fan motor.
However, a field change-out of a compressor may require checking proper phase.
5.3.3. Variable Speed Compressor Phase Check
The gForce Ultra unit has a Variable Speed Compressor (VS Compressor) with a Variable
Frequency Drive (VFD) which is factory wired and run tested to governor the phasing and
rotation direction. The wire connections between the VS Compressor and the VFD have very
specific connections, and these are shown on the wire diagrams. The only time a phase check
is needed is when a VS Compressor or VFD is during a field change-out. An out of phase VS
Compressor will not turn ON and the VFD will show an error message.
To phase check the VS Compressor, under the dap4 MENU I
– MANUAL CONTROL (Service
Level), turn the VS Compressor ON by momentarily energizing Cool 1. See dap4 IOM
instructions for details. As soon as the VS Compressors comes ON, observe the VFD display
for any error message then turn the Cool 1 OFF.
If a VFD error message is observed, review the electrical wiring diagram to make sure the proper
connections between the VFD to the VS Compressor are correct.