I have installed the 50 amp pool heater connected to the 50 amp GFCI breaker and is located outside. And I have connected to a 60 amp breaker at the panel. After a couple of seconds, when I turn on the heater, it trips my 100 amp main breaker. What would be the reason?
My 50 amp GFCI breaker is working fine. I have checked that. The total amp at the 100 amp breaker; it was around 2 amp without any appliance operating and 52 amp something with the heater on, which is less than 100 amp. Since it is the old panel, I assume there is an issue with the 100 amp breaker.
Please guide me what can I do to fix this issue.