I'm feeding a new distribuion panel that will serve multiple 208/120 3ph panels and some 208v, 3ph equipments. The connected load is approx 1050 amp at 208v 3ph. Im picking a transformer size for this New Dist. Pnl. I'm picking a 480v 500KVA and that's base on the secondary output of 1388A. Am I correct or can I go with a smaller Transformer. I believe the next lower sizes is 350KVA and that only allows for 972Amps. The other question is that a demand factor has not been applied to the connected load. If I new what demand factor to use I made be able to reduce the transformer size. I'm just confused regarding transformer size.
demand or connected which?
- Thread starter jrvazzer
- Start date
- Status
- Location
- Lockport, IL
- Occupation
- Retired Electrical Engineer
The transformer should be sized on the basis of calculated load, not just connected load. I suspect that you can't just apply one demand factor to the total load, but would have to apply separate demand factors to separate loads, depending on the types of loads and the type of facility under consideration. But if you knew the appropriate demand factors, and were able to obtain a calculated load that is below the connected load, then you can (and should) size the transformer according to the lower value.
Hameedulla-Ekhlas
Senior Member
- Location
- AFG
Charlie has already recommended you an excellent idea but let me add some more information. Addition to the demand factor, take consideration of diversity factor for sizing the transformer too in case all buildings are not typical.
- Status