Breakers, Transformers and Generators

These calculators size equipment for a given load. Get a minimum breaker rating, the kVA of a transformer, the size of a generator from running and starting watts, a calculated electrical load and the available fault current, plus conduit bend layouts.

Tools in this group

• Breaker Sizing Calculator — Enter the load or a motor's full-load current to get the minimum rating and the next standard breaker size.
• Electrical Conduit Bending Calculator (Offset, Stub-Up, Saddle) — Enter the offset height and angle, a stub-up height, or an obstruction height to get the marks to put on the conduit.
• Electrical Load Calculator — Enter the floor area, appliances and heating or AC to get the calculated load in VA and amps and a service size.
• Fault Current Calculator — Enter the transformer and the feeder to get the available fault current at both ends, in kA.
• Generator Size Calculator — List the loads with their running and starting watts to get the generator size in kW and kVA.
• Transformer Sizing Calculator — Enter the load and voltages to get the kVA you need, the standard transformer size and its primary and secondary currents.
• Transformer Turns Ratio Calculator — Find the turns ratio, the secondary voltage or the number of secondary turns of an ideal transformer.