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START UP
DESCRIPTION OF STANDARD
EQUIPMENT
Solid State Electronic Heat Pump Control
Provides efficient 30-minute defrost cycle. A thermistor
sensor and speed up terminal for service along with
a 10- minute defrost override are standard on the
electronic heat pump control.
High Pressure Switch
Provides refrigerant circuit high pressure protection.
Includes lockout circuit that is resettable from room
thermostat.
Compressor Control Module
Provides short cycle protection for the compressor
which extends compressor life, as well as high and low
pressure switch monitoring and alarm functions.
Service Lights
One service light indicates when service is required.
• Check System – detects high or low pressure
switch operation for compressor protection.
OPTIONAL CFM (Q36H2D, Q42H2D,
Q48H2D AND Q60H2D ONLY)
These units are shipped from the factory set to operate
at the optional CFM level shown in Table 9. This
provides lower operating sound levels for non-ducted,
free discharge applications. This CFM level will reduce
the system capacity performance by approximately 2%
at the same energy efficiency.
Rated CFM is required for ducted applications for
maximum performance rating. To obtain full CFM on
these models, connect jumper wire as follows:
1. Disconnect all power to the unit. Failure to do so
may result in damage to the motor.
2. Open return air service panel
3. Open inner control panel cover
4. Locate low voltage terminal strip. There is a
pink jumper wire with both ends attached to
terminal marked "G2". Move one end of this
jumper to terminal "Y".
5. Reverse steps to reassemble.
IMPORTANT INSTALLER NOTE
For improved start-up performance, wash the indoor
coil with a dishwasher detergent.
Manual 2100-603
Page
28 of 44
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 and the
compressor contactor is allowed to energize.
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.
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 even one hour may have a negative
impact on the bearing due to oil pump out.
All three phase scroll compressors used in the Q-Tec
series 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 motor may be changed by reversing any two line
connections to the unit.
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Troubleshooting
