Wiring - Main Power; Wiring - Low Voltage Wiring; Optional Climate Controls Seq. Of Op; Figure 15 Component Location - Bard Q-TEC Q24H2D Series Installation Instructions Manual

WIRING – MAIN POWER
Refer to the unit rating plate and/or Table 2 for wire
sizing information and maximum fuse or "HACR
Type" circuit breaker size. Each unit is marked with
a "Minimum Circuit Ampacity". This means that the
field wiring used must be sized to carry that amount
of current. Depending on the installed KW of electric
heat, there may be two field power circuits required. If
this is the case, the unit serial plate will so indicate. All
models are suitable only for connection with copper
wire. Each unit and/or wiring diagram will be marked
"Use Copper Conductors Only". These instructions
MUST BE adhered to. Refer to the National Electrical
Code (NEC) for complete current carrying capacity
data on the various insulation grades of wiring material.
All wiring must conform to NEC and all local codes.
The electrical data lists fuse and wire sizes (75°C copper)
for all models, including the most commonly used heater
sizes. Also shown are the number of field power circuits
required for the various models with heaters.
The unit rating plate lists a "Maximum Time Delay
Relay Fuse" or "HACR Type" circuit breaker that is to
be used with the equipment. The correct size must be
used for proper circuit protection, and also to assure that
there will be no nuisance tripping due to the momentary
high starting current of the compressor motor.
The disconnect access door on this unit may be locked
to prevent unauthorized access to the disconnect.
FIGURE 15
COMPONENT LOCATION
ELECTRIC
HEATERS
UNIT
MOUNTED
THERMOSTAT
LOCATION
DEHUMIDIFICATION
CONTROL
(OPTIONAL)
See "Start Up" section for information on three phase
scroll compressor start-ups.
The field wiring connections are located behind the
top and hinged panel in the circuit breaker panel. See
Figure 15.
WIRING – LOW VOLTAGE WIRING
230/208V, 1 PHASE AND 3 PHASE EQUIPMENT
DUAL PRIMARY VOLTAGE TRANSFORMERS.
All Equipment leaves the factory wired on 240V tap.
For 208V operation, reconnect from 240V to 208V tap.
The acceptable operating voltage range for the 240 and
208V taps are as noted in Table 3.
NOTE: The voltage should be measured at the field
OPTIONAL CLIMATE CONTROLS
SEQUENCE OF OPERATION
The standard Climate Control Option X is a remote
thermostat connection terminal block. See Figure 17 or
Figure 18 for wiring diagram. Compatible thermostats
are listed in Table 4.
The Climate Control Option E is an electronic,
programmable thermostat with humidistat. The
subbase of the thermostat is factory wired to the front
SIDE FIELD WIRE
panel of the unit. See Figure 19 for wiring diagram.
ENTRANCE
Compatible for use with Energy Recovery Ventilator.
This unit has a refrigerant reheat circuit that is
controlled by a 3 way valve.
REMOTE
THERMOSTAT
When the humidity is above the setpoint of the
TERMINAL
BLOCK
humidistat, the compressor circuit and the 3 way valve
are energized and the evaporator airflow is reduced.
INDOOR
The 3 way valve directs hot discharge gas into a
BLOWER
separate desuperheating condenser circuit that reheats
the conditioned air before it is delivered to the room.
When the humidistat is satisfied, the system switches
back to normal air conditioning mode.
CIRCUIT
If the thermostat calls for cooling during
BREAKER PANEL
dehumidification mode, the call for cooling takes
& CONTROLS
precedence over the dehumidification and the unit will
cool until the thermostat is satisfied. Once the call for
cooling is satisfied, the unit may continue to dehumidify.
LOWER
CONTROL
If the thermostat calls for heat when the unit is in
PANEL
the dehumidification mode, the electric heaters will
energize and the evaporator airflow will return to the
heating airflow. When the thermostat is satisfied, the
electric heaters will turn off and the airflow will be
reduced and the system will continue to dehumidify
until humidistat is satisfied.
TABLE 3
OPERATING VOLTAGE RANGE
TAP
240V
208V
power connection point in the unit and while
the unit is operating at full load (maximum
amperage operating condition).
RANGE
253 – 216
220 – 187
Manual 2100-603
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