Bard WH262, Installation Instructions Manual

Page: 17 / 24

Manual 2100-350D
Page 17 of 24
START UP
PHASE MONITOR
All units with three phase 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.
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. The heat pump wall thermostats perform multiple
functions. Be sure that all function switches are
correctly set for the desired operating mode before
trying to diagnose any reported service problems.
4. Check all power fuses or circuit breakers to be sure
they are the correct rating.
5. 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 for constant air circulation.
HEATING – A 24V solenoid coil on reversing valve
controls heating cycle operation. Two thermostat
options, one allowing “Auto” changeover from cycle to
cycle and the other constantly energizing solenoid coil
during heating season and thus eliminating pressure
equalization noise except during defrost, are to be used.
IMPORTANT INSTALLER NOTE
For improved start up performance wash the indoor coil
with a dishwashing detergent.
HIGH PRESSURE SWITCH
All 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. All three
phase units incorporate a phase monitor to ensure proper
field wiring. See the “Phase Monitor” section in this
manual.
Verification of proper rotation must be made any time a
compressor is changed or rewired. 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.
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 rotations, as well as, substantially
reduced current draw compared to tabulate values.
The direction of rotation of the compressor may be
changed by reversing any two line connections to the
unit.