Nexans heating cables in stairs should be laid lengthways on the steps so that they lie only on the horizontal surfaces. The cables are covered with a 30 - 50 mm screed or paving slabs embedded in mortar.
Use DEFROST SNOW with 4-5 cable runs in each step, or TXLP series resistance heating cable, which is well suited for medium or large installations.
With sand/slabs: Max. 30 W/m (9 W/ft) of cable*
Asphalt: Max. 30 W/m (9 W/ft) of cable
Concrete: Max. 35 W/m (10 W/ft) of cable
Note: When using long cables, potential capacitance problems may occur.
* If unsure about the thermal conductivity of the sand, please limit the power to 25 W/m (7,6 W/ft).
The heating cables shall be installed with even spacing. Avoid concentration of heating cables that will result in uneven cable and surface temperatures, and might cause overheating and breakdowns in the worst case. Always measure insulation and conductor resistance before and immediately after covering the cables. Be aware that the insulation resistance tends to become lower at high temperature, e.g. when measuring the cable in warm asphalt.