Remote Thermostat and Low Voltage Control
Connection
Remote Thermostat
All VTAC units are factory configured to be controlled
by using a single stage heat/cool remote wall mounted
thermostat. The thermostat may be auto or manual
changeover as long as the control configuration matches
that of the VTAC unit.
To connect the wall mounted thermostat:
1. Pull the disconnect switch.
2. Unscrew and remove the control box panel.
3. Select which side to run your thermostat wire.
4. Run the wires through the side hole in the box to
reach the connection terminal wiring.
5. Make the connections, appropriately matching the
wires as shown in the wiring diagram.
6. Reattach the control box cover.
Front Desk Control Terminals
The VTAC has built-in provisions for connection to an
external switch to control power to the unit. The switch can
be a central desk control system door switch.
For desk control operation, connect on side of the switch to
the D1 terminal and the other to the D2 terminal. When the
circuit is closed, unit operation will stop.
NOTE: The desk control system and switches must be
field supplied.
Maximum Wire Length for Desk Control Switch
AWG Wire Size
Maximum Length (ft.)
24
400
22
600
20
900
18
1500
16
2000
Auxiliary Fan Control
The VTAC also has the ability to control a 24VAC relay to
activate an auxiliary or transfer fan. The outputs are F1 and
F2 on the control board.
To connect the relay, simply wire one side of the relay to F1
and the other side to F2.
NOTE: The relay and auxiliary fans must be field
supplied. The relay must be 24VAC @ 100mA or less.
Interface Definition
Terminal Code
Wire Connection Function
C
Common Ground Terminal
GH
Call for High Fan
GL
Call for Low Fan
B
Call for Heat Pump (Reversing Valve)
Y
Call for Compressor
W
Call for Heating (Electric)
R
24VAC to Wall Thermostat
NOTE: It is the installer’s responsibility to ensure that
all control wiring connections are made in accordance
with the installation instructions. Improper connection
of the thermostat control wiring and/or tampering
with the unit’s internal wiring can void the equipment
warranty and may result in property damage, personal
injury, or death. Questions concerning proper
connections to the unit should be directed to the
factory.
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