I have a 32 amp 240-240/120volt auto transformer. The incoming breaker keeps on tripping almost daily when drawing no more than 15 amps continuous when connected to only 120volt loads. Also, I have a 1/2 HP centrifugal pump which I’m unable to run because the breaker trips on start up, even Without any other load connected. The pump is connected at 240volt. Is there a setting to increase the over current trip on the breaker?
Hello henry-cabrera,
I don't know your particular setup, but inrush current can be very disheartening as sometimes nuisance trips can occur and may be difficult to diagnose. Something to consider however is that all breakers do not have the same "trip curve".
What I mean is breakers generally have 2 mechanisms for tripping, thermal and mechanical. The thermal mechanism takes a little time to heat up and trip. The mechanical is generally fast acting. The amount of influence these two mechanisms has can be graphed and presented to the user as a "tripping curve". This allows you to understand the behaviour of the breaker over time when subjected to certain overload situations because of inrush current.
The curve are designated with a letter, B curve, C curve, D curve etc. Sometimes, if the circuit is subject to high inrush currents, for instance inductive loads of motors or inrush current to some other devices, the curve of the breakers is chosen to suit the application. Inductive loads are often passed through "D" curve breakers. "D" curve breakers can handle many multiples of the trip current for a certain time without tripping to handle the shock load of energising a device or devices.
You know you have an inrush problem with the pump so swapping put the breaker for a higher tripping curve may provide a solution. I would suggest a 32 amp "D" curve breaker to see if that resolves the issue in the first instance. I am presuming of course a "D" curve breaker hasn't already been fitted.
I hope this may help.
Trevor
