View Full Version : Sizing the kva for TRANSFORMERS
MRCHAD
Jun 1, 2007, 06:05 PM
What Would Be The Right Size Transformer.
Power Coming In Would Be Single Phase 480
Output Is 120v , About 4.2a
I Figure About 1kva Would Be Plenty
tkrussell
Jun 2, 2007, 03:21 AM
Since VA (AC Power) is volts times amps:
120 VAC X 4.2 Amps= 504 VA
So the 1.0 KVA xfer is almost double what is needed, offering plenty to spare, if the load is resistive. If the load is inductive, such as a motor, it is just about the correct size.
nielseno
Jun 7, 2007, 03:30 PM
What Would Be The Right Size Transformer.
Power Coming In Would Be Single Phase 480
Output Is 120v , About 4.2a
I Figure About 1kva Would Be Plenty
I think you'll probably be OK. I think you just need to multiply your 120*4.2 and w/ a 1 KVA rated supply you would have a safety factor of 2.