How to choose a Circuit Breaker with the correct AMP rating for protection of a transformer.
As an electrical engineer / electrical technician you will come across this scenario a from time to time. In my case, the transformer has already been installed, and this transformer fed a block of offices and a small fabrication shop. As the company expanded they decided to add a machine shop with a new machinery like Lathe machine, Milling machine, drill presses, machines for electroplating and the installed transformer could no longer feed the added load. The a new transformer had already been procured before management asked the question of what size of Circuit breaker would be used to protect this new Power Transformer from overload and short circuit. There a lot of factors to be considered when sizing a circuit breaker but the four major ones that should be on your mind are The ambient temperature of the environment where the breaker is to be installed. Continuous running current when all connected loads are switched on (Maximum load current) Pre