Bard W42AC-B Installation Instructions Manual Download

Page: 18 / 42

Manual 2100-692E

Page

18 of 42

compressor contactor and up into the upper control
panel where the connections are made. If field power is
supplied to the right of side of the unit, the low voltage
wires can be run under the field wire shield to access
the low voltage terminal strip.
When field wires are supplied through the back of the
unit, flexible conduit must be extended through the
back of the unit and terminate into the knock-outs on
the upper control panel (see Figure 19).

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,
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 8 on page 20 for
more information.

Low Voltage (24VAC) Connections

These units use a 24-volt AC low voltage circuit.

terminal is the

24VAC common and is grounded.

terminal is the

indoor blower input

terminal is the

1st Stage input for cooling.

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 24).

B/W1

terminal is the

1st stage electric heat

terminal is the

2nd stage heat

(if equipped).

terminal is the

ventilation input

. This terminal

energizes any factory-installed ventilation option and
indoor blower.

terminal is the

dehumidification input

. If installed, this

terminal energizes any factory-installed dehumidification
option.

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
for compressor cooling standard operation. Y1 and Y2
are connected with a brass jumper bar which can be
removed to enable Balanced Climate mode. Units with
an economizer will not have the brass jumper installed.
Refer to vent manuals for instructions on how Balanced
Climate works with each vent.

NOTE:

Units with mechanical dehumidification

require an additional connection to be made

when enabling Balanced Climate. Refer to

dehumidification supplemental instructions for

this step.

To operate in Balanced Climate mode, a 2-stage
cooling thermostat is required. The lower indoor
airflow operation is overridden by utilizing a 2-stage
thermostat. If the call for cooling is not satisfied
within a given time frame or temperature differential
(specified by the thermostat), the thermostat will send
a signal to Y2 which then increases the blower speed

TABLE 3

Additional Low Voltage Connections (if applicable)

Terminal

Unit

Description

V Control

Option Only

Discharge Air Sensor,
10K Ohm

V Control

Option Only

Discharge Air Sensor,
10K Ohm

F, V Control