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Question – 200 Amp Main Circuit Breaker Tripping – Part 1

My 200 amp main electrical circuit breaker trips. Should I replace it?

I have a 200A main panel which is fully utilized. I recently put in an inground swimming pool and a finished basement – so I put in a main lug 20 circuit 100A panel downstream to service my pool and basement.

Everything went all right until recently my 200A main breaker occasionally trips. This happened tonight when both central air units were on, (one 4-ton unit one 2-ton unit), my pool pump (15A), and my washing machine.

I went to the main panel and measured 19A off one leg and 45 off the other. I may try load balancing and move the 4-ton unit to the leg drawing 19A – but I can’t understand why this would trip a 200A main???

Keep in mind that the starting amps of any motor is quite high. This is commonly called Lock Rotor Amps (LRA) and will be found on the A/C Unit Label Information. If both A/C units start at the same time and there is a moderate load in the home you may trip your main breaker.

So how can you solve this? One option is to have a Time Delay Relay installed on one of the A/C units as to prevent both units from starting at the same time. The relay can be installed on the thermostat control voltage side of the circuit.

You mentioned that you may try to balance the load of the A/C units, however they are most likely 240 Volts and should themselves be balanced. You can balance the panel loads by repositioning the higher 120 Volt loads onto the low reading busses.

200 Amp Main Circuit Breaker Tripping – Part 2

200 Amp Main Circuit Breaker Tripping – Part 3

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