Multiple Parallel Temperature Sensors; Humidity, Pressure, And Universal Sensor Wiring; Temperature Sensor Wire Type And Size - Honeywell T775U2006 Installation Instructions Manual

WIRING

Multiple Parallel Temperature Sensors

Multiple sensors can be parallel-series wired to sense
average temperatures in large spaces. To maintain
control accuracy, the number of sensors to be parallel-
series wired must be of the n
16, etc.). See Fig. 3.
SENSORS
TO T775 CONNECTIONS (SENSOR A) OR (SENSOR B).
Fig. 3. Parallel-series wiring of sensors.
SENSORS A AND B ARE POLARITY INSENSITIVE WHEN USING A 1097 OHM PTC TEMPERATURE SENSOR.
1
SENSOR B IS USED ONLY IN RESET APPLICATIONS ON THE T775U20006.
2
Fig. 4. Sensor Wiring — 2-wire shielded cable connection from Sensor A to temperature sensor.
Humidity, Pressure, and Universal Sensor
Wiring
Sensors with a 0-5 Vdc, 0-10Vdc or 4-20mA input to the
T775U must be wired to the Sensor A terminal. Sensor B
is used only as a temperature input.
Sensors use standard AWG 18 unshielded wire. For cable
runs greater than 25 feet, shielded cable is
recommended.
The sensors in Fig. 5 – 8 beginning on page 6 are
examples and illustrate voltage and current wiring for 3-
wire and 2-wire sensors to the Sensor A terminal. For
2
power (for example, 4, 9,
M24548
T
T
T
T

Temperature Sensor Wire Type and Size

Temperature sensors use standard AWG 18/2 unshielded
wire. For cable runs greater than 25 feet or where
electrical interference may be a problem, shielded cable
is recommended. See Fig. 4.
Refer to "Temperature Sensor Calibration" on page 10 for
wire size selection where cable runs are longer than 25
feet.
SHIELDED
CABLE
SENSOR A
NOTE: SHIELDED CABLE MUST BE
CONNECTED TO A SEPARATE EARTH
1
GROUND.
SENSOR B
HOWEVER, DO NOT GROUND
SHIELDED CABLE AT SENSOR END.
2
SHIELDED
CABLE
NOTE: TO MINIMIZE NOISE PICKUP,
MAKE SENSOR CONNECTION FROM
SHIELDED CABLE AS CLOSE AS
POSSIBLE TO SENSOR BODY.
terminal wiring details, see Fig. 11 and Table 2 on page 8.
Other sensors are supported. See sensor descriptions on
page 2.
NOTES:
1. Other transmitters can be wired in the same
manner. For example, the 0-10Vdc wiring
shown in Fig. 5 on page 6 with the H76XX
sensor can also be done with the P7640 or
any other transmitter.
2. The T775U V terminal outputs 18 Vdc.
5
T775U SERIES 2000 CONTROLLER
SENSOR
M24549A
62-0255–05