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Manual 2100-511F
Page 16 of 27
START UP (Continued)
IMPORTANT INSTALLER NOTE
For improved start up performance wash the indoor coil
with a dish washing detergent.
HIGH & LOW PRESSURE SWITCH
All W**H wall mounted air conditioner series models are
supplied with a remote reset for the high and low
pressure switch. If tripped, this pressure switch may be
reset by turning the thermostat off then back on again.
THREE PHASE SCROLL COMPRESSOR
START UP INFORMATION
Scroll compressors, like several other types of
compressors, will only compress in one rotational
direction. Direction of rotation is not an issue with
single phase compressors since they will always start
and run in the proper direction.
However, three phase compressors will rotate in either
direction depending upon phasing of the power. Since
there is a 50-50 chance of connecting power in such a
way as to cause rotation in the reverse direction,
verification of proper rotation must be made.
Verification of proper rotation direction is made by
observing that suction pressure drops and discharge
pressure rises when the compressor is energized.
Reverse rotation also results in an elevated sound level
over that with correct rotation, as well as substantially
reduced current draw compared to tabulated values.
Verification of proper rotation must be made at the
time the equipment is put into service. If improper
rotation is corrected at this time, there will be no
negative impact on the durability of the compressor.
However, reverse operation for over one hour may have
a negative impact on the bearing due to oil pump out.
NOTE: If compressor is allowed to run in reverse rotation
for several minutes, the compressor’s internal
protector will trip.
All three phase ZP compressors are wired identically
internally. As a result, once the correct phasing is
determined for a specific system or installation,
connecting properly phased power leads to the same
Fusite terminal should maintain proper rotation
direction.
The direction of rotation of the compressor may be
changed by reversing any two line connections to the
unit.
PHASE MONITOR
All units with three phase scroll compressors are
equipped with a 3 phase line monitor to prevent
compressor damage due to phase reversal.
The phase monitor in this unit is equipped with two
LEDs. If the Y signal is present at the phase monitor
and phases are correct the green LED will light.
If phases are reversed, the red fault LED will be lit and
compressor operation is inhibited.
If a fault condition occurs, reverse two of the supply
leads to the unit. Do not reverse any of the unit factory
wires as damage may occur.
CONDENSER FAN OPERATION
Applies to W42, W48 and W60 models only. The
condenser fan motor on 230/208 volt, one and three
phase, 60 HZ units is a two-speed motor that comes
factory wired on high speed for peak performance. If
ambient conditions permit, it can be reconnected to low
speed (red wire) for lower sound level. See wiring
diagram.
50 HZ models must have fan wired on low speed.
These models are factory wired on low speed.
SERVICE HINTS
1. Caution owner/operator to maintain clean air filters
at all times. Also, not to needlessly close off supply
and return air registers. This reduces airflow
through the system, which shortens equipment
service life as well as increasing operating costs.
2. Check all power fuses or circuit breakers to be sure
they are the correct rating.
3. Periodic cleaning of the outdoor coil to permit full
and unrestricted airflow circulation is essential.