On the secondary side, it's powering a 225A panel
appears to be 112kva, but you are assuming that you have a fully loaded 225A panel which may or may not be the case., knock off a few amps and you could easily get by with 75.
appears to be 112kva, but you are assuming that you have a fully loaded 225A panel which may or may not be the case., knock off a few amps and you could easily get by with 75.
Here's how I get it: 225 amps times 208 volts times 1.732 gives me 81KVA. The next size up is 112.5.How did you calculate 112KVA?
How did you select a 225A panel in the first place? That should not be step 1, as others have already said. First, you calculate the load. Then you pick the equipment ratings (transformer and panel). The last step is picking the overcurrent settings.it is in design stage. For a 225A 120/208V, 3ph, 4W panel, what should the transformer and primary side protection size be designed for?
I believe you can use a 75kVA transformer and use a 225A panel main breaker as the transformer secondary protection device (within 125% of transformer secondary) and still be o.k.