Hi to all,

I am new to the forum and in desperate need of help.
I am working on a 3phase star connected macerator pump that keeps tripping the breaker. The braker is rated ot 0.63-1 A and the pump draws 1 A in Star connected form. The pump is primed and pumps perfectly but then suddenly trips. The valves on both sides are open and free of obstructions.

The pump does not run hot either.
This installation is only three years old.

Any help will be appreciated.

 

There is more than one approach to this. My first idea is about the breaker being rated for EXACTLY the expected current. Nobody with good sense does that. If there is any pre-heating of the breaker, that will cause it to trip too soon. I'm talking about corrosion on the connections. Circuit breakers sometimes go bad, too. I suspect the breaker, not the motor.