69-1020—2
2
C7089B OUTDOOR SENSOR
Fig. 1. Typical locations for outdoor sensor.
Wiring
CAUTION
Keep wiring at least one foot away from large
inductive loads such as motors, line starters,
lighting ballasts, and large power distribution
panels. Failure to follow these wiring practices
can introduce electrical interference (noise),
which can cause erratic system operation. Use
shielded cable to reduce interference when
rerouting is not possible.
IMPORTANT
Erratic temperature readings from a sensor can
occur as a result of any of the wiring practices
described below. These practices must be
avoided to assure proper operation. Use
shielded cable to reduce interference if rerout-
ing of sensor wiring is not possible.
a.
Do not route temperature sensor wiring
with building power wiring, next to control
contactors or near light dimming circuits,
electric motors or welding equipment.
b.
Avoid poor wiring connections.
c.
Avoid intermittent or missing building earth
ground.
CAUTION
Disconnect the power supply before connecting
the wiring to prevent electrical shock or equip-
ment damage.
M7514
Fig. 2. Wiring diagram for the C7089B
Outdoor Sensor to the thermostat.
OPERATION
The C7089B Outdoor Sensor converts outdoor ambient
temperature to a resistance that the thermostat can
interpret. The outdoor temperature is displayed when the
Information key is pressed.
NOTE: The thermostat Installer Setup mode number 24
must be set to 01 for the outdoor temperature to be
displayed.
The C7089B has a negative temperature coefficient
(TC), which means that the resistance increases as the
temperature decreases. Fig. 3 shows the resistance
characteristics of the C7089B Sensor.
1
2
3
2
1
USE APPROPRIATE MOUNTING MEANS FOR THE TYPE
OF STRUCTURE.
PLUG WIRING HOLE WITH NON-HARDENING CAULK OR PUTTY.
OT TERMINAL LOCATION VARIES WITH MODEL.
C7089
WIRING HOLE
THROUGH
STRUCTURE
W
Y
O
G
R
B
C
OT
OT
T8600 SUBBASE
M10165
3
Wiring must comply with applicable codes, ordinances and
regulations.
1. Wire the C7089B Outdoor Sensor to the OT
terminals on the thermostat. If the leadwire
provided with the C7089B is not long enough, run
cable to a hole at the selected C7089B location.
Color-coded, 18-gauge thermostat wire is recom-
mended. For an example of general wiring of the
C7089B, see Fig. 2. Pigtail wiring can be used.
2. Mount the C7089B in its mounting clip.
3. Plug wiring hole using nonhardening caulk or putty.
