LOW VOLTAGE CONTROL CONNECTIONS
Use 7/8 inch knockout on the left hand side panel to bring low
voltage wiring into air handler.
CAUTION: Use 7/8 inch plastic bushing provided to prevent
chafing wires.
All field control wiring to be connected at screw terminals of
connector board. See Figure 8.
Remove control wiring harness supplied with 2HW electric heat
accessory and discard. Every connector board is supplied with a
complete electric heat wiring harness connected to the lower right
hand corner of connector board (See Figure 8). Plug in free end
of wiring harness to electric heat control board. If the transformer
kit is installed, discard electric heat wiring harness attached to
connector board. Install wiring harness provided with transformer
accessory at the connection in lower right hand corner of connec-
tor board.
Field supplied low voltage wiring must be kept as short as possi-
ble and away from the blower motor wires. Refer to Table 2, 3 or
5 for minimum wire size.
The 24 volt power supply is provided by an internally wired low
voltage transformer. However, if the unit is connected to a 208 volt
power supply the low voltage transformer must be rewired to the
208 volt tap. See the unit wiring label.
See Figure 9, 10 and 11 for low voltage terminal connections.
If thermostat used has an adjustable heat anticipator, see Table
below for proper setting.
BLOWER SPEED SELECTION
All variable speed air handlers (N*VS) are designed to deliver
constant CFM regardless of the external static pressure (ESP) in
the ductwork. Therefore, if too many supply registers are closed,
a filter becomes clogged, or there is a restriction in the ductwork,
the motor will automatically operate at a higher speed to compen-
sate for the higher ESP. This may result in a higher operating
sound level.
To Set Cooling CFM:
Refer to the outdoor unit technical guide for the recommended
airflow with the matching evaporator coil. Refer to the label on the
blower housing or Table 1 for the possible HI speed cooling and/or
Electric Heater with
Cooling or
Electric Heater Only
KW
Adjustable
Heat
Anticipator
2HW
5 - 20
0.1 Amps
HEAT ANTICIPATOR SETTING
FIGURE 7 - Blower Connections
GRD.
FAN MOTOR SPEED TAP RECEPTACLE
ON TRANSFORMER OR HEATER ACCESSORY
PURPLE
BLUE
PURPLE
BLUE
VARIABLE
SPEED MOTOR
5 PIN CONNECTOR
WIRE HARNESS
TO CONNECTOR
BOARD (16 PIN
CONNECTOR)
208/230V
FIGURE 8 - N*VS Connector Board
SCREW
TERMINAL
BOARD
HUMIDISTAT
ACCESSORY
JUMPER
DELAY
PROFILE TAP
BLOWER MOTOR
INTERFACE HARNESS
CONNECTS HERE
COOL TAP
ELECTRIC
HEAT TAP
ADJ TAP
ELECTRIC HEAT OR TRANSFORMER WIRING
HARNESS CONNECTS HERE
JUMPER IN STORED POSITION
(Vertically on RH side, pins “A” and “B”)
HEAT PUMP JUMPER
JUMPER IN “A” CFM
POSITION
(Horizontally jumper two “A” pins)
535.03-N1Y
6
Unitary Products Group
