Wiring - Main Power; Wiring - Low Voltage Wiring; General - Bard Q-TEC Series Literature Assembly

WIRING – MAIN POWER
Refer to the unit rating plate and/or Table 1B (page 7)
for wire sizing information and maximum fuse or 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 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 field wiring connections are located behind the top
panel in the circuit breaker panel. The return air panel
must be removed first. This panel is equipped with
a door switch, which shuts the unit down when it is
removed. The filter rack must be removed next.
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 2.
TABLE 2
Operating Voltage Range
TAP
240V
208V
NOTE: The voltage should be measured at the field
power connection point in the unit and while
the unit is operating at full load (maximum
amperage operating condition).
Manual 2100-738A
Page 20 of 71
RANGE
253 - 216
220 - 187
The standard Climate Control Option X is a remote
thermostat connection terminal block. See Figure
14 on page 22 for wiring diagram. Compatible
thermostats are listed in Table 3.
The Climate Control Option D is an electronic,
programmable thermostat. The subbase of the
thermostat is factory wired to the front panel of the
unit. See Figure 15 on page 23 for wiring diagram.
Compatible for use with Energy Recovery Ventilator or
Economizer.
The Climate Control Option H is an electronic,
programmable thermostat and CO
subbase of the thermostat and CO
factory wired to the front panel of the unit. See Figure
16 on page 24 for wiring diagram.

GENERAL

This unit is equipped with a variable speed ECM motor.
The motor is designed to maintain rated airflow up to
the maximum static allowed. It is important that the
blower motor plugs are not plugged in or unplugged
while the power is on. Failure to remove power prior
to unplugging or plugging in the motor could result in
motor failure.
CAUTION
Do not plug in or unplug blower motor
connectors while the power is on. Failure to
do so may result in motor failure.
TABLE 3
Wall Thermostat
Thermostat
3 stage Cool; 3 stage Heat
Programmable/Non-Programmable
8403-060
Electronic
(1120-445)
HP or Conventional
Auto or Manual changeover
2 stage Cool; 2 stage Heat
Programmable/Non-Programmable
8403-081 Electronic
(VT8650U5500B) HP or Conventional, Auto or Manual
changeover with Humidity and
Occupancy Sensor, BACnet
controller. The
2
controller are
2
Predominant Features