Installation instructions for fixed resistance floor cable
The heating cables T2Green, T2Black, T2Blue must not be shortened, crossed or fixed with less than 50 mm between them, except for the self-regulating cable T2Red. Heating cables can be laid under ceramic tile or natural stone floors. The thermal resistance of the floor above the cables should be as low as possible.
BeFORE INSTALLING, READ THE INSTRUCTIONS INCLUDED WITH THE PRODUCT
Do not walk on the cables during installation. Avoid mechanical damage to the heating cables! If the heating cable is damaged, use a suitable repair kit.
Peace thermostat
Because the heating cables are of constant power, by law they must be controlled by a thermostat that regulates the temperature using an external floor temperature sensor. Alternatively, the cables can be controlled with an nVent RAYCHEM thermostat operating in room temperature sensing mode, but with a floor sensor temperature limiter. The heating cables should be installed in conjunction with a thermostat that ensures product compliance with the Eco Design Directive, such as NRG-DM, GREEN LEAF or SENZ WIFI.
Wood floors
In certain conditions, T2Red, T2Green-5, T2Blue-10 cables can also be installed under wood (laminate) and parquet floors. For wooden floors, heating cables should be embedded in a layer of concrete 15 - 30 mm thick. The control thermostat should be regulated by a floor sensor (or by a room sensor with a floor limiter). The limit value of the floor sensor should be set at 27° C (maximum temperature). The wood species should be compatible with underfloor heating systems. There must be no thermal barrier (such as carpet or furniture) on top of the floor.
Floor construction
All materials used in floor construction must be compatible with underfloor heating systems.
How to install a heating cable in a concrete screed
Mounting heating cable to concrete floor with hot glue
Heating cable adhesive is included in every RAYCHEM kit: T2Red, T2Black, T2Blue
- Tile flooring (ceramic tiles or natural stone)
- Tile adhesive
- Waterproofing layer (optional for wet surfaces)
- Self-leveling screed designed for underfloor heating system
- Heating cable T2Red, T2Green, T2Blue, T2Black
- Concrete substrate with thermal insulation
High adhesion heating cable fixing adhesive is designed for hot mounting with a gun (ø 12 mm). The processing time of the adhesive is 30 seconds, depending on the size, temperature and thermal conductivity of the material to be glued. The adhesive reaches full strength after the glued part has cooled to room temperature.
- Machining temperature: +200°C to +220°C.
- Temperature resistance: +70°C.
The adhesive can be used to attach heating cables to primed plaster surfaces, gypsum boards, primers and ceramic tiles.
1. Measurement one, before laying the heating cable
1A. Perform a measurement of insulation resistance, between the protective braid and heating conductors.
- Minimum test voltage of 500 V DC, recommended 1000 V DC.
- Duration of measurement 60 seconds.
Reserve the value in the appropriate place in the table located in the acceptance protocol.
1B. Make a measurement of the resistance of the heating cable, between the supply wires.
Reserve the value in the appropriate place in the table located in the acceptance protocol.
2. Install the thermostat box and the supply cable
Always use a thermostat with floor temperature measurement! Install a standard fi 60 deep flush-mounted box on the wall at a height of 120 - 150 cm.
The thermostat has an air temperature sensor installed in its housing, so:
- Must be located in the same room where the floor heating will be made.
- Mount it in a place away from places where there are large temperature fluctuations such as a radiator, TV, fireplace, large drafts, etc.
- Do not mount the thermostat on the wall on which the sun's harsh rays fall.
From the box to the floor, pull the heating cable power cable. The connection of the heating cable to the cold wire must be placed directly in the screed layer and must not be inserted into the protective tube. This connection must be handled carefully, i.e. do not bend the wires at the connection point or subject it to mechanical stress.
3. Installation of the heating cable, (as an example) using hot glue
The substrate must be clean, stable and hardened, without cracks or substances that limit adhesion. Large cracks in the substrate should be filled before laying cables. Uneven surfaces must be leveled before installation. Prime the entire surface. The concrete substrate must be completely dry before installing the heating cables. Never lay heating cables through expansion joints in the floor. If the floor has expansion joints, use separate heating cables for each zone. Do not lay the heating cable in places where they could be exposed to damage, such as when drilling holes, or where they could be covered by furniture placed on the floor. If you mount the cables to the mounting grid or reinforced mesh do it with nylon ties - self-locking. Do not install cables with wire.
Before installing the cable, calculate the spacing between the heating wires. Marked on the drawing with the symbol X.
4. Floor sensor installation
It is recommended to install the floor sensor in a protective tube so that there is the possibility of replacing it in case of damage. The end of the protective tube should be properly sealed. The sensor should be placed centrally between the two heating cables, as close to the surface as possible, e.g. directly under ceramic tiles or other flooring.
The protective tube with a brass plug is included in every nVent RAYCHEM floor kit. See How to install a temperature sensor in a heating mat?
5. Measurement two, after laying the heating cable
5A. Perform a measurement of insulation resistance, between the protective braid and heating conductors.
- Minimum test voltage of 500 V DC, recommended 1000 V DC.
- Duration of measurement 60 seconds.
Reserve the value in the appropriate place in the table located in the acceptance protocol.
5B. Make a measurement of the resistance of the heating cable, between the supply wires.
Reserve the value in the appropriate place in the table located in the acceptance protocol.
6. Sealing heating cables in glue or concrete
Installed heating cables you can pour self-leveling screed or spread adhesive mortar, always distribute along the heating cores.
While doing so, take precautions not to strip and move the heating cables and the floor temperature sensor cover pipe.
Always follow the recommendations of the manufacturers of floor adhesives.
7. Measurement three, after the heating cable is sealed and the mortar has dried
7A. Perform a measurement of insulation resistance, between the protective braid and heating conductors.
- Minimum test voltage of 500 V DC, recommended 1000 V DC.
- Duration of measurement 60 seconds.
Reserve the value in the appropriate place in the table located in the acceptance protocol.
8B. Make a measurement of the resistance of the heating cable, between the supply conductors.
Enter the value obtained in the appropriate place in the table located in the acceptance protocol.