Viega IM-HC 561174 1120, Installation Manual

Installation

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IM-HC 561174 1120 Basic Heating Control

4.1.3 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.

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 (part number 16020). This mounts in the 

Outdoor Sensor enclosure and allows up to four controls to have outdoor 

sensors within one enclosure.

Multiple Outdoor Sensor 
module mounting location

Wires from 
outdoor sensor 
to control 
terminals
(Com Sen - 
Out Sen)

Sensor is built 
into the 
enclosure