Single-zone snow melt control installation and operation manual | 7
Wiring the outdoor sensor
Wires from
outdoor sensor to
controlʼs outdoor
sensor and sensor
common terminals
Sensor is built into
the enclosure
Sensor wiring
Mounting the outdoor sensor
Note:
The temperature sensor (thermistor)
is built into the sensor enclosure.
• Remove the screw and pull the front cover
off the sensor enclosure.
• Mount the outdoor sensor directly onto a
wall or a 2" x 4" electrical box. When wall
mounting the outdoor sensor, the wiring
should enter through the back or bottom of
the enclosure. Do not mount the outdoor
sensor with the conduit knockout facing
upward as rain could enter the enclosure
and damage the sensor.
• To prevent heat through the wall from
affecting the sensor reading, it may be
necessary to install an insulating barrier
behind the enclosure.
• Mount the outdoor sensor on a wall
which best represents the heat load
on the building (a northern wall for most
buildings and a southern-facing wall for
buildings with large south-facing glass
areas). Do not expose the outdoor sensor
to heat sources such as ventilation or
window openings.
• Install the outdoor sensor at an elevation
above the ground that will prevent
accidental damage or tampering.
Wiring the outdoor sensor
• Connect 18 AWG or similar wire to the two
terminals provided in the enclosure and
run the wires from the outdoor sensor to
the control. Do not run the wires parallel to
telephone or power cables. If the sensor
wires are located in an area with strong
sources of electromagnetic interference
(EMI), use shielded cable or twisted pair or
run the wires in a grounded metal conduit.
If using shielded cable, connect the shield
wire to the Com or Com Sen terminal on
the control and not to earth ground.
• Follow the sensor testing instructions
in this manual and connect the wires
to the control.
• Replace the front cover of the
sensor enclosure.
Sensor with
bottom-entry wiring
Sensor with
rear-entry wiring
Sensor mounted
onto 2" x 4"
electrical box
Wires from outdoor
sensor to control’s
outdoor sensor
and sensor
common terminals
Sensor is built into
the enclosure
Mounting the outdoor sensor
