Service Manual

© 2015 680_D - 10/15 8 of 48
• The temperature sensor (thermistor) is built into the sensor
enclosure.
•
Remove the screw and pull the front cover off the sensor
enclosure.
• The outdoor sensor can either be mounted directly onto a
wall or a 2 " x 4 " electrical box. When the outdoor sensor is
wall mounted, the wiring should enter through the back or
bottom of the enclosure. Do not mount the outdoor sensor
with the conduit knockout facing upwards because rain
could enter the enclosure and damage the sensor.
•
In order to prevent heat transmitted through the wall from
affecting the sensor reading, it may be necessary to install
an insulating barrier behind the enclosure.
•
The outdoor sensor should be mounted on a wall which
best represents the heat load on the building (a north-facing
wall for most buildings and a south-facing wall for buildings
with large south-facing glass areas). The outdoor sensor
should not be exposed to heat sources such as ventilation
or window openings.
• The outdoor sensor should be installed at an elevation above the
ground that will prevent accidental damage or tampering.
Mounting the Outdoor Sensor --------------------------------------------------------------------------
Sensor with
bottom-entry wiring
Sensor with
rear-entry wiring
Sensor mount
ed
onto 2" x 4"
electrical box
• 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),
shielded cable or twisted pair should be used or the wires
can be run in a grounded metal conduit. If using shielded
cable, the shield wire should be connected 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.
Wiring the Outdoor Sensor -----------------------------------------------------------------------------
Wires from outdoor
sensor to control’s
outdoor sensor an
d
sensor common
terminals
Sensor is built into
the enclosure
Com
14
Out
15
The Universal Sensor 082 is designed to mount on a pipe or in a temperature
immersion well. The sensor should be placed downstream of a pump or after
an elbow or similar fitting. This is especially important if large-diameter pipes
are used as the thermal stratification within the pipe can result in erroneous
sensor readings. Proper sensor location requires that the fluid is thoroughly
mixed within the pipe before it reaches the sensor.
Strapped to Pipe
The Universal Sensor can be strapped directly to the pipe using the cable tie
provided. Insulation should be placed around the sensor to reduce the effect
of air currents on the sensor measurement.
Mounting the Boiler and System Sensors --------------------------------------------------------------