Danfoss DEVIreg 850, Installation And User Manual

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DEVIreg™ 850 ground and roof sensors
Installation and user manual 11
2 .3 .4 Example with roof sensors
In this example a roof with several dormers is heated. Depending on the number of
zones and required safety it is relevant to install 2-3 roof sensors.
1 2 3
1 2 3
1 2 3
1 2 3
Sensor no. 1 is placed in shady side of the
front. It is the most important as all melting
water passes the sensor until the gutter is dry.
As snow is likely to slide down here, the spot
is one of the last to dry up.
Sensor no. 2
is also important as the shaded
dormer roof is more flat, which might cause
sudden snow slides on a dry roof. The dor-
mers could be the lower prioritized zone in a
dual zone system.
Sensor no. 3 is relevant if a higher detection safety is required. It could both be placed
near another down pipe or in the gutter valley. Thus it can be an additional sensor to both
no. 1 and 2 and can be prepared for later installation.
2 .3 .5 Extending the roof sensor cable
The roof sensor is a sensor part with a sensor cable built
in one.
A 15-meter cable is supplied with the roof sensor to be
connected with the DEVIreg™ 850 controller.
If the appropriate spot is located out of this range, a
feeder cable extension for the sensor may be needed. This sensor cable extension must
be a 4-wired cable with a diameter in accordance with the table in Appendix A – Sensor
cable extension.
Note each new colour of the 4 wire cable feeder extensions (white, white, red and
black) . Dual zone sensors: Do NOT join feeder cable extensions from separate
zones