The Bench Test is complete! Proceed with actual thermostat installation and
connect the remaining wiring to the HVAC system.
TR16 Control Unit Wiring Guide
Wall Display Unit Connection (J1)
Connect the WDU to the Control Unit J1, using Cat3/5 22/24 Ga twisted pair wiring (recommended) or
typical HVAC thermostat wire (18/20 Ga). Connect according to wiring diagram.
Caution: Miswiring the WDU to Control unit connections may result in damage to the WDU.
12VDC Power to the Control Unit (J4)
Connect the external 12VDC, 500mA transformer provided to jack J4. This is a center ground connector.
HVAC System Connection (J5)
Determine the HVAC System type, Standard Gas/Electric or Heat Pump. Refer to the specific HVAC
system type wiring diagram in the Installation Manual. Use typical 18/20GA thermostat wire. Standard
thermostat wiring labels and typical wire colors:
W is the stage 1 Heat output. White wire.
G is the Fan output. Green wire.
Y1 is stage 1 Compressor output. Yellow wire.
O is the Heat Pump Changeover valve output. Orange wire. (can be Brown)
(O terminal can be used for W2, 2nd stage heat output for standard HVAC systems)
Y2 is the 2nd stage compressor output. Black wire
NOTE: when using existing thermostat wires, don’t assume wire colors are correct, check the
HVAC system end also.
HVAC Transformer Connections 24RH and 24RC
Single Transformer HVAC Systems
Most central HVAC systems have a common heating and cooling system transformer. This is the default
configuration of the Control Unit’s HVAC Systems 24RH and 24RC terminals and they are connected
together by a red jumper wire. This jumper MUST be installed. 24R wiring from the HVAC system can
be connected to either the RH or RC terminals.
Separate Heating and Cooling Transformer HVAC Systems
If the Heating/Cooling system has separate heating and cooling transformers, you MUST REMOVE the
red jumper wire between RC and RH on the control board. Connect the cooling system transformer to
RC and the heating system transformer to RH.
NOTE: With separate transformer systems, the Fan (G) terminal is connected to the RC
transformer.
Set Dipswitch SW1
Set Dipswitch SW1 on the TR16 HVAC Control Unit for the correct HVAC system configuration.
HVAC System Type: Standard Gas/Electric or Heat Pump.
Also set the Fan type for Standard systems or the Changeover Valve type for Heat Pumps systems.
IMPORTANT: SW1 MUST be set to the correct HVAC type for proper HVAC system operation!
RS485 Network Connection (J3)
The TR16 RS485 communications network is a 2 wire, half duplex network. Connect the RS485 network
connection J3 T+ and R- to the network Data + and Data – wires. Always wire RS485 connections + to +
and – to – regardless of labels (B+/D+/T+). Network ground wire is advisable.
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