In summary, an Ametherm thermistor is required with following ratings: 5.0 Ohms at 25ºC and 250 Joules. AS32 5R020 (5 Ohms at 25ºC, 300 Joules, 20A max steady state current) would be suitable. Please note: Steady state current is not calculated because in this example, the current goes through the contactor.