Manual 2100-504
Page
16 of 20
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
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. Switching to heating cycle at 75°F or higher outside
temperature may cause a nuisance trip of the remote
reset high pressure switch. Turn thermostat off then
on to reset the high pressure switch.
3. Check all power fuses or circuit breakers to be sure
they are the correct rating.
4. Periodic cleaning of the outdoor coil to permit full
and unrestricted airflow circulation is essential.
SEQUENCE OF OPERATION
COOLING
– Circuit R-Y makes at thermostat pulling
in compressor contactor, starting the compressor and
outdoor motor. The G (indoor motor) circuit is
automatically completed on any call for cooling
operation or can be energized by manual fan switch on
subbase of constant air circulation. On all 230 volt units
there is a one-minute off delay on the blower motor.
460 volt models do not have an off delay. On a call for
heating, circuit R-W1 make at the thermostat pulling in
heat contact for the strip heat and blower operation. On
a call for second stage heat, R-W2 makes bringing on
second heat contactor, if so equipped.
START UP
IMPORTANT INSTALLER NOTE
For improved start up performance wash the indoor coil
with a dish washing detergent.
HIGH PRESSURE SWITCH
The WL484 and WL605 models are supplied with a
remote reset high 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 ZR3 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.
