Wiring - Main Power; Wiring - Low Voltage; Low Voltage Connections; Unit Shutdown Feature - Bard 11EER WA W18AB-A User's Application Manual

Wiring – Main Power
WARNING
!
Electrical shock hazard.
Do not operate this equipment without an earth
ground attached and always disconnect the
remote electric power supplies before servicing.
Electrical shock can result in serious injury or
death.
Refer to the unit rating plate for wire sizing information
and maximum fuse or circuit breaker size. Each
outdoor 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 ensure 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. To
convert for the locking capability, bend the tab located
in the bottom left-hand corner of the disconnect
opening under the disconnect access panel straight
out. This tab will now line up with the slot in the door.
When shut, a padlock may be placed through the hole
in the tab preventing entry.
See "Start Up" section for important information on
three phase scroll compressor start ups.
See Tables 12 and 13 on pages 30 and 31 for
electrical specifications.
Wiring – Low Voltage
All 230/208V 1 phase and 3 phase equipment have
dual primary voltage transformers. All equipment leaves
the factory wired on 240V tap. For 208V operation,
Manual 2100-689H
Page 16 of 42
reconnect from 240V to 208V tap. The acceptable
operating voltage range for the 240 and 208V taps are:
Tap: 240 Range: 253 – 216
Tap: 208 Range: 220 – 187
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).
For low voltage wiring, an 18 gauge copper, color-coded
cable is recommended. See Table 7 on page 18 for
more information.
Low Voltage (24VAC) Connections
These units use a 24-volt AC low voltage circuit.
C terminal is the 24VAC common and is grounded.
G terminal is the indoor blower input.
Y1 terminal is the 1st Stage input for cooling.
Y2 terminal is the 2nd Stage compressor input for
cooling (if equipped with an economizer) or Y2 disables
Balanced Climate mode if the Y1-Y2 jumper is removed
(see page 22).
B/W1 terminal is the 1st stage electric heat.
W2 terminal is the 2nd stage heat (if equipped).
A terminal is the ventilation input. This terminal
energizes any factory-installed ventilation option and
indoor blower.
D terminal is the dehumidification input. If installed, this
terminal energizes any factory-installed dehumidification
option.
L terminal is 24 volt alarm active output.
For units equipped with an alarm relay:
1 terminal is the normally closed contact on the relay.
2 terminal is the normally open contact on the relay.
3 terminal is the common contact on the relay.
See Table 3 for additional low voltage connections on
auxiliary terminal strip.
Unit Shutdown Feature (Standard on All Models)
The RT terminal is the 24VAC transformer output,
and the R terminal is the 24VAC hot terminal for the
operation of the equipment. RT and R are connected
with a brass jumper bar which can be removed and RT
and R connected to an external NC (normally closed)
contact such as a fire/smoke detector that will cause
shutdown of the equipment upon activation.
Balanced Climate™ Feature (Standard on All Models)
All units are equipped with the capability of running
in Balanced Climate mode. This mode is designed to
enhance the comfort level by reducing the indoor airflow
amount and extending the run time to help extract more
humidity during cooling operation. The Y1 terminal
is the 24VAC input for Balanced Climate compressor
cooling operation. The Y2 terminal is the 24VAC input