DEVIreg 850 Ground And Roof Sensors User Manual
- June 1, 2024
- DEVI
Table of Contents
DEVIreg 850 Ground And Roof Sensors
Specifications
- Product: DEVIregTM 850 ground and roof sensors
- Manufacturer: DEVI
- Website: www.DEVI.com
Product Information
The DEVIregTM 850 ground and roof sensors are designed to measure temperature and moisture levels on surfaces for efficient control of ice and snow melting systems. These sensors are crucial components that provide data to the DEVIregTM 850 controller for optimal operation of the heating system.
Installation and User Manual
1. Sensors and Control Zones
The sensors can be assigned to different control zones based on the type of area they are monitoring, such as walkways, parking areas, steps, stairs, roofs, roof edges, gutters, and downpipes.
1.1 Sensor Types and Function
Ground sensors are used for ground areas while roof sensors are used for roof areas. Both types of sensors measure temperature and moisture levels on the surface to provide data for the heating system control.
1.3 Assign Sensors to Control Zones
It is important to assign sensors to control zones based on the specific requirements of the heating system. Consult with the system designer for guidance on sensor placement and zone assignments.
2. Placing and Installation of Sensors
2.1 Placing Ground Sensors
Ground sensors should be placed at least 1 meter within the boundaries of the heated zone and should not be covered to ensure accurate readings and efficient operation of the system.
FAQ
- Q: How many sensors can be assigned to a control zone?
- A: The DEVIregTM 850 supports a maximum of 4 sensors per control zone.
Sensors and control zones
This section guides you through a short introduction to the terms used in the manual:
- Area type
- Sensor type
- Controller
- Control Zones
Finally you will be able to assign a number of sensors to the chosen control zones.
Sensor types and function
Identify the type(s) of area prepared for the DEVI ice and snow melting system, by looking at the fig. below:
- Walkways and parking areas
- Steps and stairs
- Roofs and roof edges
- Gutters and down pipes For ground areas like 1 and 2 you have one or more ground sensors.
For roof areas like 3 and 4 you have one or more roof sensor
The ground and roof sensors both measure two things on the sensor surface:
- temperature
- moisture from ice, snow, hail or rain
These measurements are input to the DEVIreg™ 850, and it decides how the ice and snow melting system should control the heated areas. Details about the setup of the controller can be found in the DEVIreg™ 850 installation manual.
Control zones
A DEVIreg™ 850 and up to 4 sensors are able to control an area as a single zone, but can also control more areas as 2 separated control zones. 2 control zones consits of minimum 2 heating elements + 2-4 sensors and can be:
- Combi zones = when you have both a roof and a ground area
- Dual zones = e.g. if steps should have a better performance than a walkway
If the power supply is limited, both combi and dual zones gives you the
possibility to prioritize which zone to operate rst. A DEVIreg™ 850 and up to
4 sensors give the following 5 control options:
Assign sensors to control zones
There are some good reasons to have 2 or more sensors in one control zone.
- Higher degree of detection safety, which is relevant for larger, complex or busy roof and ground areas.
- Approx. 1 hour faster ground system, as one sensor measures the ground temperature and other sensors measure the moisture whereas a single sensor must switch between temperature and moisture measurements.
Now decide how the ice and snow melting system should be operated and assign
the sensors to the control zones. In case of questions the system designer
must be consulted
Placing and installation of sensors
At this point you must have identified and assigned sensors to the control zones as prescribed in section 1.
In this section 2 you will be guided through a correct placing and installation of the sensors:
- For placing and installation of ground sensors see section 2.1.
- For placing and installation of roof sensors see section 2.2.
Placing ground sensors
Placing ground sensors in appropriate spots is very important for the performance of the ice and snow melting system. The appropriate spot must fulfill some characteristics, where the below 2 are the most important: The sensors must be placed minimum 1 m within the boundaries of the heated zone. The sensors must not be covered or prevented from being exposed to snow or rain. This includes dirt, leaves and pebbles.
Placing the first ground sensor in a zone
Find one who knows the area and make him describe the area function and
weather conditions.
The first ground sensor in a zone must now be placed where the first snow
appears. The appropriate spot can be found by following below steps:
- a) Where the heated area is in shade all day. Look e.g. for algae.
- b) Where e.g. a wind shield make the snow drift
- c) Where the most trafic from shoes or car wheels happens
If you have a dual zone system, the first sensor for the other zone must be placed by following the same steps above.
Placing the following ground sensors in a zone
The following ground sensors in a zone must be placed where the surface dries up last. The appropriate spot can be found by following below steps:
- a) Where the heated area is in shade all day
- b) Where the melting water accumulates e.g. due to hollows in the area
- c) So the whole zone is covered, but min. 1 meter from other sensors
If there is doubt about the appropriate spot, prepare a second spot for later use
Example with ground sensors
- In this example a lower step section (1), a walkway platform (2) and an upper step section (3) is heated. Depending on a number of zones and detection safety, 2-3 ground sensors is installed.
- Sensor no. 1 is the most important as this is placed where snow is likely to appear first due to shade and snow drift and also because the spot is stepped on by pedestrians.
- Sensor no. 2 is also important as the platform is object to water puddles. Here the shaded spot will dry up last. If the power supply is limited, the platform could be a low-priority zone in a dual-zone system.
- Sensor no. 3 is relevant if more detection safety is required, as addition to sensor no. 1. Can be prepared for later installation.
Extending the ground sensor cable
The ground sensor consists of two parts, a sensor part with a sensor cable and a sensor tube. A 15-meter cable is supplied with the sensor part. Approx. 0.5 m of this cable should be coiled inside the bottom of the sensor tube, leaving 14.5 meter 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.
Installing ground sensors
At this point you must have located the appropriate spots for the ground sensors and extended the feeder cable if necessary as prescribed in section 2.1. The sensor part and the sensor tube may now be installed in connection with the actual construction work and connected at a later date. The following applies for all types of installations.
- a) The base below the sensor tube must be hard, e.g. a concrete plate or similar, in order to ensure that the sensor is not pushed into the ground if e.g. a lorry runs over it. The tube is designed to be mounted on a plate using the two screw holes inside the tube.
- b) Place the sensor tube in between the heating cables with a minimum distance of 1 cm.
- c) The sensor tube must be positioned so that it is push with the surrounding terrain and so that the sensor part must be placed so that the upper brass surface is horizontal. installation pipe
- d) Lay a conduit for the sensor cable between the sensor tube and the DEVIreg™ 850 controller
Installation in asphalt:
The temperature around the sensor part and sensor tube must not exceed 80°C. A wooden dummy or similar must replace the sensor while asphalt is poured and cooled down. The conduit must be a metal tube that can withstand the high temperatures.
- e) Ensure that the sensor tube is closed with the supplied cap before the concrete is poured or the bricks are laid. Make sure that air gaps are filled with cement.
- f ) Coil approx. 0.5 m of the sensor cable inside the tube. If the sensor cable needs an extension, see section 2.1.4. installation pipe with sensor cable
- g) Place the sensor part inside the sensor tube until it is horizontally pushed with the edge of the sensor tube and rests on the collar inside the tube.
- h) The sensor part may be inspected using the two holes around the edge of the sensor tube. The grooves on the outside of the sensor part correspond with the holes in the sensor tube
Placing roof sensors
Placing roof sensors in appropriate spots is very important to the performance of the Ice & Snow melting system. The appropriate spot must fulfil some requirements, where the below 2 are the most important: The sensors must be placed minimum 1 m within the boundaries of the heated zone. The sensors must not be covered and prevented from being exposed to snow or rain. This includes dirt and especially leaves in the gutters.
Placing the first roof sensor in a zone
Find one who knows the area and make him describe the area’s function and weather conditions. The first roof sensor in a zone must now be placed where ice and snow cause most problems.
The appropriate spot can be found by following the below steps:
- a) Where the heated area is in shade or oriented to the north/west
- b) In the main gutter close to the main downpipe
If you have a dual zone system, the first sensor for the other zone must be placed by following the same steps above.
Placing the following roof sensors in a zone
The following roof sensors in a zone must be placed where the surface dries up latest. The appropriate spot can be found by following below steps:
- c) Where the snow slides e.g. due to roof joints or gutter valleys
d) In other gutters, close to other down pipes
e) So the whole zone is covered, but min. 1 meter from other sensors If there is doubt about the appropriate spot, prepare a second spot for later use.
Guiding plates
If a roof area is oriented to the south and the roof slope is steep it can be
exposed to strong sun radiation. In that case it can be necessary to install
guiding plates above the sensor, so the slowly dripping melting water from the
roof hit the roof sensor.
If there is doubt about the appropriate spot, prepare a second spot for later
use.
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.
- Sensor no. 1 is placed in the 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 at, which might cause sudden snow slides on a dry roof. The dormers 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.
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
Installing roof sensors
At this point you must have selected the appropriate spots for the roof sensors and extended the feeder cable if necessary as prescribed in section 2.3. The roof sensor may now be installed in connection with the actual construction work and connected at a later date. The following applies for all types of installations.
- a) The sensor must be placed between or next to the heating min. 1 cm cables, with a distance of minimum 1 cm between sensor and heating cable.
- b) The sensor must be placed so that the upper brass surface is horizontal. If the sensor is placed on an angled roof, the sensor must be levelled until the surface is horizontal.
- c) Fasten the sensor by using the attachments on the sensor or glue it to the surface.
Technical specifications
Technical data
Type number:
• Ground
• Roof
| ****
D850 G1 Sensor D850 R1 Sensor
---|---
Voltage:| 24VDC +10%/-20% (18-26VDC)
Power consumption:
• Ground
• Roof
| ****
Max. 13W
Max. 8W
IP class:| IP 67
Ambient temperature:
• Ground
• Roof
| ****
-30˚C to +70˚C
-50˚C to +70˚C
Sensor type:| Devibus connected moisture sensor(s)
Sensor lead:| 15 m of 4×1 mm2 (may be extended in accordance with the table in
appendix A)
Indication:| 2 x 16-character illuminated display.
Measurements
• Ground sensor
• Sensor tube (ground)
• Roof sensor
| ****
Depth = 87 mm; Heigth = 74 mm Depth = 93 mm; Height = 98 mm
Depth = 15 mm; Height = 23,5 mm; Width 216 mm
Appendix A
Sensor cable extension
Ground system
| Number of sensors: | 1 or 2 | 3 | 4 |
|---|---|---|---|
| Cable type | Max length (m) | Max. length (m) | Max length (m) |
| 1 mm2 | 300 | 150 | 80 |
| 1.5 mm2 | 450 | 225 | 120 |
| 2.5 mm2 | 750 | 380 | 200 |
| 4 mm2 | 1200 | 600 | 310 |
Roof system
| Number of sensors: | 1 | 2 | 3 | 4 |
|---|---|---|---|---|
| Cable type | Max length (m) | Max length (m) | Max length (m) | Max length (m) |
| 1 mm2 | 400 | 100 | 130 | 75 |
| 1.5 mm2 | 600 | 150 | 200 | 110 |
| 2.5 mm2 | 1000 | 250 | 330 | 190 |
| 4 mm2 | 1600 | 400 | 525 | 300 |
Connections
Dual zone sensors: Do not join sensor cable extensions from separate zones.
Warranty
A 2-year product warranty is valid for:
-
DEVIreg™ 850 ground and roof sensors. Should you, against all expectations, experience a problem with your DEVI product, you will find that Danfoss’s DEVIwarranty valid from the date of purchase on the following conditions: During the warranty period Danfoss shall offer a new comparable product or repair the product if the product is found to be faulty by reason of defective design, materials or workmanship. The repair or replacement. The decision to either repair or replace will be solely at the discretion of Danfoss. Danfoss shall not be liable for any consequential or incidental damages including, but not limited to, damages to property or extra utility expenses. No extension of the warranty period following repairs undertaken is granted. The warranty shall be valid only if the WARRANTY CERTIFICATE is completed correctly and in accordance with the instructions, the fault is submitted to the installer or the seller without undue delay and proof of purchase is provided. Please note that the WARRANTY CERTIFICATE must be filled in, stamped and signed by the authorized installer performing the installation (The installation date must be indicated). After the installation is performed, store and keep the WARRANTY CERTIFICATE and purchase documents (invoice, receipt or similar) during the whole warranty period. DEVIwarranty shall not cover any damage caused by incorrect conditions of use, incorrect installation or if the installation has been carried out by non-authorized electricians. All work will be invoiced in full if Danfoss is required to inspect or repair faults that have arisen as a result of any of the above. The DEVI warranty shall not extend to products that have not been paid in full. Danfoss will, at all times, provide a rapid and effective response to all complaints and inquiries from our customers. The warranty explicitly excludes all claims exceeding the above conditions.
For full warranty text visit www.devi.com.
WARRANTY CERTIFICATE
Danfoss A/S
- DEVI
- devi.com
- +45 7488 2222
- EH@danfoss.com
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