1 1LE* Motor PTC[edit | edit source]
For the protection of the motor winding for motor type 1CV2162A (order number 1LE*) Siemens does use a sensor triplet (3x PTC, 2 clamps).
Media:1LE1601-1DA23-4AB4 datasheet de en.pdf Media:KRIWAN 3xPTC.pdf
The execution of a sensor triplet looks as follows:
This means, that there are 3 PTC sensors connected in series (one for monitoring each of the motor windings), only 2 wires a run to the motor terminal box.
According to DIN VDE V 0898-1-401 VDE V 0898-1-401 (former DIN 44082 Thermistors; PTC for thermal machine protection) such PTC sensor triplets do have a cold resistance R25 of <=300Ω at a temperature of 25°C