7
TWITE INSTRUMENTS
THERMOSTAT MODEL TD-196 OPERATING MANUAL
INSTALLATION CONT..
S
ENSOR
I
NPUT
C
ONNECTIONS
.
Sensor cables must be of the SHEILDED type and must not exceed 500 Metres.
Sensor cables should not run parallel or in the same duct as high voltage cables.
The shield of the sensor cable must be connected to the EARTH terminal and must
only be connected at one end, the shield must be continuous at each sensor drop.
Sensors require one wire for common
(usually red)
and one for positive
(usually
black).
If more than one sensor is used
(optional extra)
. The common
(usually red)
may be
tied to one wire which can be connected to all sensor commons. i.e.. for 8 sensors 9
wires need only be used.
The sensors
(if a single sensor is used)
negative wire
(usually black)
must be con-
nected to terminal
SEN -
and the positive wire
(usually red)
to
SEN +.
Extra sensors
(optional extra)
positive wire
(usually red)
must be connected to
terminal
SEN +
and the negative wire
(usually black)
must be connected to its
corresponding channel number marked INPUTS 2 to 8 inclusive.
Sensors are numbered before shipment and are calibrated at the factory. Therefore
each sensor’s negative wire
(usually black)
must be connected to its’ corresponding
sensor input. For instructions on how to re calibrate sensors see CALIBRATE
SENSORS.
