What is the power consumption of a PTC probe wired to the LT3SM protection relay ?

The current flown via the PTC probe is 1-2mA
2mA is flown at low temperature (PTC probe has low resistance)
1mA is flown at high temperature (PTC probe has high resistance)
If PTC probe will be tempoary replaced by resistor 250 Ohms (simulates low temperature) its power consumption will be I^2*R = 2mA * 2mA * 250 Ohms = 1 mW

Publié pour:Schneider Electric Belgium