Viega Basic Heating Control Installation Manual page 9

Installing the outdoor sensor
The Outdoor Sensor includes a
10kΩ thermistor that provides an
accurate measurement of the
outdoor temperature. The sensor
is protected by a white U.V. resistant
plastic 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
sensor is wall mounted, the wiring
should enter through the back or
bottom of the enclosure. Do not
mount the sensor with the conduit
knockout facing upward as 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 that 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). The 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, and where it
will not be covered by drifting snow
during the winter.
VIEGA 1-800-976-9819
InstALLAtIon - CHAPtER 5
Connect 18 AWG or similar wire to
the two terminals provided in the
enclosure and run the wires from
the 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 sensor terminal on the
control and not to earth ground.
Replace the front cover of the
sensor enclosure.
When more than one Basic Heating
Control is used on a project, the
Outdoor Sensors can be combined
into one enclosure by adding the
Multiple Outdoor Sensor module
(stock code 16020). This mounts
in the Outdoor Sensor enclosure
and allows up to four controls to
have outdoor sensors within
one enclosure.
9
Installing the supply sensor
Note: This sensor is designed to
mount on a pipe or in a temperature
immersion well.
The Supply Sensor can be strapped
directly to the pipe using a plastic
cable tie. Insulation should be
placed around the sensor to reduce
the effect of air currents on the
sensor measurement.
The Supply 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.
When using the Supply Sensor with
a Viega Mixing or Injection Station,
insert the sensor into the immersion
well on the elbow below the
circulator pump.
Connect 18 AWG or similar wire
to the two wires of the sensor
and then 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 sensor terminal on the
control and not to earth ground.
PI-16015-03/09