Pro1 IAQ T721i - Page 2

5
Wiring
8
Wiring
7
6
Technician Setup Menu
Power Supply
1
2
3
Factory-installed jumper,
remove only when installing on 2-transformer system.
Use either O or B terminals for changeover valve.
4
A 24 VAC 500mA common connection is required with this thermostat.
Wiring
Replacement Thermostat Wiring
If you are replacing a thermostat, make
note of the terminal connections on the
thermostat that is being replaced. In some
cases the wiring connections will not be
color coded. For example, the green wire
may not be connected to the G terminal.
Loosen the terminal block screws. Insert
wires then retighten terminal block screws.
Place nonammable insulation into wall
opening to prevent drafts.
1.
2.
3.
This thermostat requires a 24V common
wire to the C terminal.
4.
Caution:
Electrical Hazard
All components of the control system
and the thermostat installation must
conform to Class II circuits per the
NEC Code.
Warning:
Do not overtighten terminal block screws, as this can damage the terminal block.
A damaged terminal block can keep the thermostat from tting on the subbase
correctly or cause system operation issues.
Installation Tip
Max Torque = 6in-lbs.
Failure to disconnect the power
before beginning to install this
product can cause electrical shock or
equipment damage.
Wiring Chart
For all systems, the following terminals are wired according to whether you have a
single or dual transformer system as shown:
SINGLE
TRANSFORMER
SYSTEM
DUAL
TRANSFORMER
SYSTEM
RH RC C G
24 VAC HOT
JUMPER SHOULD REMAIN
INSTALLED
24 VAC-Heat
*REMOVE PROVIDED
JUMPER
24 VAC-Cool
*REMOVE PROVIDED
JUMPER
24 VAC Common
500mA
*FROM COOL
TRANSFORMER
Blower / Fan
Blower / Fan
24 VAC Common
500mA
*FAILURE TO REMOVE PROVIDED JUMPER ON DUAL TRANSFORMER INSTALLATIONS COULD CAUSE SEVERE DAMAGE TO HVAC SYSTEMS
O Terminal
B Terminal
Heat pump changeover valve-- Energized during cooling
Heat pump changeover valve-- Energized during heating
If using in Heat Pump without Auxiliary or Emergency heat application,
please see wiring diagram on previous page.
Note: Devices such as a oat switch that mechanically break circuits should be
installed so that they break the control wire (Y) not the power (R). Interrupting the
power circuit will shut o power to the thermostat completely and not allow it to
operate.
To enter tech setup:
1. Press and hold the + and - buttons for 3 seconds.
2. Press and hold the TECH button for 3 seconds.
3. Congure the installer options as desired using the table below. Use the + or - buttons to
change settings and the lower left and right buttons to move from one step to another.
4. To exit tech setup: press and hold the + and - buttons for 3 seconds, or wait 60 seconds.
Tech Setup Steps
Adjustment Options
Default
LCD Will Show
Swing Setting Tip
Temperature swing, sometimes called dierential or cycle rate, can be customized
for this individual application. For most applications choose a swing setting that is
as wide as possible without making the occupants uncomfortable.
O
This feature allows the installer to
change the calibration of the room
temperature display. For example, if the
thermostat reads 70 degrees and you
would like it to read 72 then select +2.
0
Room
Temperature
Calibration
You can adjust the room
temperature display to read
4˚above or below the factory
calibrated reading.
ON
The compressor short cycle delay
protects the compressor from “short
cycling”. This feature will not allow
the compressor to be turned on for 5
minutes after it was last turned o.
Compressor
Short Cycle
Delay
The swing setting often called “cycle
rate”, “dierential”, or “anticipation” is
adjustable. A smaller swing setting will
cause more frequent cycles and a larger
swing setting will cause fewer cycles.
Cooling
Swing
Heating
Swing
COMP DELAY
COOL SWING
0.8
HEAT SWING
The swing setting often called “cycle
rate”, “dierential”, or “anticipation” is
adjustable. A smaller swing setting will
cause more frequent cycles and a larger
swing setting will cause fewer cycles.
0.8
The cooling swing setting is
adjustable from 0.2˚ to 2˚. A
swing setting of 0.5˚will begin
cooling at approximately 0.5˚
above the setpoint and stop
approximately 0.5˚ below the
setpoint.
The heating swing setting is
adjustable from 0.2˚ to 2˚. A
swing setting of 0.5˚will begin
heating at approximately 0.5˚
below the setpoint and begin
approximately 0.5˚ above the
setpoint.
CALIBRATE
When set to ON this thermostat
will operate a heat pump system
(default). If set to OFF this
thermostat will operate a
conventional system, and the next
tech step will not appear.
ON - Congured to operate
heat pump system.
OFF - Congured to operate
conventional system
See page 5 for terminal
designations.
Heat Pump
ON
Selecting “ON” will not allow
the compressor to be turned
on for 5 minutes after the
last time the compressor was
switched o. Select “OFF” to
remove this delay.
HEAT PUMP
0.8
0.8
REMOVE JUMPER
Typical 2H/1C Heat Pump System
RC
RH
Y
C
W/E
G
W2
COMPRESSOR
RELAY
FAN RELAY
AUXILIARY
HEAT RELAY
EMERGENCY
HEAT RELAY
COOL CHANGE
OVER VALVE
HEAT CHANGE
OVER VALVE
C
R
L2
L1(HOT)
O
B