Honeywell H7625B- User Manual

INSTALLATION INSTRUCTIONS

63-2579—3

H7625B; H7635B,C; H7655B

Duct-Mount and Outdoor-Mount

Humidity/Temperature Sensors

APPLICATION

The H7625B, H7635B, H7655B Duct-Mount and H7635C
Outdoor-Mount Humidity/Temperature Sensors are
universal Relative Humidity transmitters that can be
powered with either a +18 to 36 Vdc or 24 Vac supply.
The sensors use a half-wave bridge rectifier to convert
AC power to a usable DC voltage. The device also
includes a 20K ohm temperature sensor for optional use.

The humidity sensors are designed with a field-
selectable 4 to 20 mA, 0 to 5 Vdc, or 0 to 10 Vdc output
signal equivalent to 0 to 100% RH. All units are shipped
from the factory with a default setting to accept AC power
with three-wire, 0 to 10 Vdc loop-powered output.

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 ratings given in instructions and on the
product to ensure 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

Electrical Shock or Equipment Damage
Hazard.
Can shock individuals or short equipment
circuitry.

Disconnect power supply before installation.

CAUTION

Equipment Damage Hazard.
Improper wiring can damage the sensor
beyond repair.

Follow the wiring instructions carefully.

Mounting

The method of mounting depends on the particular
sensor application. The following procedures include
outdoor and duct applications. Also refer to the
instructions for the electronic control.

Duct Mounting

The H7625B, H7635B and H7655B can be mounted in a
duct to sense humidity and temperature.

IMPORTANT

Select a location to expose sensor to average
duct humidity and temperature. Avoid locations
where stratification can cause sensing errors.

NOTES:

—

H7635C is weatherproof for outdoor use.
Knockouts allow 1/2 in. conduit connection.

—

To avoid damaging board during installation,
the cover can be detached completely:

1.Carefully remove wire plug from board.
2.Set the cover aside.

1.

Cut a hole in the duct just large enough to accept
the sensing element.

2.

Open case by rotating the cover counterclockwise.

3.

Mount standard 1/2 in. conduit to the case.

4.

Use case to mark mounting screw pilot hole
locations.

5.

Drill the pilot holes and fasten the sensor to the
duct.

6.

Wire the sensor. See Wiring section.

NOTE: The two free wires are thermistor wiring

connections. When connecting these, use
two wire nuts.

7.

Reattach the wire plug and cover being careful not
to pinch wires between the cover and case.