Pentax C7089B Owner's Manual

C7089B

Outdoor Sensor

INSTALLATION INSTRUCTIONS

APPLICATION

The C7089B Outdoor Sensor is used with the T8500 and
T8600 Thermostat families on models with outdoor
temperature option. It senses the outdoor temperature
for display at the touch of a key. The sensor is encapsu­lated to protect against water and contaminants, and
includes 60 in. leadwires.

SPECIFICATIONS

Operating Ambient Temperature Range:

-40 to 128°F (-40 to 53°C)

Operating Relative Humidity:

5% to 95% non-condensing

Dimensions in inches (millimeters):

2-1/4 (57) x 3/8 (10) with 60 (1524) leadwires

INSTALLATION

When Installing this Product…

1. Read these instructions carefully. Failure to follow

them could damage the product or cause a
hazardous condition.

2. Check the ratings given in the instructions and on

the product to make sure the product is suitable for
your application.

3. Installer must be a trained, experienced service

technician.

4. After installation is complete, check out product

operation as provided in these instructions.

CAUTION

Disconnect power supply before connecting wiring
to prevent electrical shock or equipment damage.

Location and Mounting (Fig. 1)

Mount the sensor where:

• setting can not be tampered with.

• there is good air circulation.

• it can measure the true outdoor ambient temperature.

• surface is flat.

• he wire distance between the C7089 and thermostat
is less than 200 feet.

Do

not

mount the sensor:

• in the direct sunlight.

• where hot or cold air blows on the sensor. Discharge
line from an outdoor compressor unit, vent or fan will
cause inaccurate temperature readings.

• where snow, ice or debris can cover it.

Use the following steps to mount the sensor.

1. Remove the sensor from the mounting clip.

2. Mark the area on the surface where the C7089B

mounting clip will be mounted.

3. Mount the clip.

®U.S. Registered Trademark • All Rights Reserved

X-XX UL

69-1020-2

C7089B OUTDOOR SENSOR

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 recom­mended. 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.

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 rerout­ing 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 equip­ment damage.

M7514

1

C7089

B

T8600 SUBBASE

1

USE APPROPRIATE MOUNTING MEANS FOR THE TYPE
OF STRUCTURE.

2

PLUG WIRING HOLE WITH NON-HARDENING CAULK OR PUTTY.

OT TERMINAL LOCATION VARIES WITH MODEL.

3

Fig. 2. Wiring diagram for the C7089B

Outdoor Sensor to the thermostat.

WIRING HOLE
THROUGH

2

STRUCTURE

3

C

OT

OT

WYOGR

M10165

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.

69-1020—2

2