Basic sizing approach
For three-phase industrial loads, estimate kVA from the connected kW and power factor. A simplified estimate is kVA = kW / power factor. For motor-heavy plants, include starting conditions and future expansion instead of sizing exactly at present running load.
Practical example
If a production line has 80 kW connected load at 0.8 power factor, the apparent load is approximately 100 kVA. A buyer may select a higher standard rating after considering starting current, voltage correction range and future load additions.
Important factors
- Actual running load versus nameplate load
- Motor starting current and drive behavior
- Input voltage fluctuation range
- Single-phase or three-phase load balance
- Ambient temperature and enclosure location
- Future capacity expansion