Specifications

Manual 2100-323
Page 11
START UP AND OPERATION
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 ZR*3 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 terminals
should maintain proper rotation direction.
The direction of rotation of the motor may be changed by
reversing any two line connections to the unit.
HIGH PRESSURE SWITCH AND
LOCKOUT RELAY (All Models Except
P1136A1-B and P1136A1-C)
The air conditioners are equipped with an auto reset high
pressure switch and lockout relay. The lockout relay may be
reset by turning the thermostat to off or satisfying the
thermostat.
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 for constant air
circulation.
HEATING – A circuit R-W1 is completed on each
heating cycle energizing electric heat if so equipped.
START UP NOTES
For improved start up performance, wash the indoor coil
with dishwasher detergent