How to measure a floor heating cable?

In order to measure the heating cable, you need a meter with a low-voltage resistance measurement function and an insulation resistance measurement function.

1. In the first measurement we measure the insulation resistance. Measurements of insulation resistance are performed to test the actual condition of the insulation of the heating cable. The minimum test voltage of the test is 500 V, the recommended voltage is 1000 V. To perform the measurement, we connect the power supply wires which we connect under one terminal of the meter, under the other terminal we connect the protective conductor. We make a measurement lasting a minimum of 60 seconds. The result obtained should be greater than 100 MΩ.
2. In the second measurement, make a low-voltage measurement of the resistance between the power wires. To make the measurement, connect the terminals of the meter under the power wires. Record the result in the installation protocol. Then compare the measured value with the table, which can be found in the installation instructions for the product. Resistance values are also located on the label stuck to the product. If the values match, it means that the product is operational and we can start the heating system.

Measurement of insulation resistance: 1. heating mat, 2 - 3. supply wires, 4. protective wire

Measurement of resistance between supply wires: 1. heating mat, 2. protective wire, 3 - 4. supply wires.

It is required that the measurements be taken three times during installation. After removing the cable from the box, after laying the cable on the floor and before taping, and the third time after laying the tiles and before connecting the thermostat. The results of all three tests must be entered in the installation protocol.