Difference between watts and volt amperes
Category: Electronics Articles
1 Feb 15
| Difference | Watts |
Valt-amperes |
|---|---|---|
| Abbreviation | W | VA |
| Calculation | For dc: Vdc X Idc | For dc: Vdc X Idc |
| Instrument need for measurement | Wattmeter (a typical multimeter cannot measure watts unless the V and I are both dc) | Typical multumeter capable of measuring VRMS and IrRMS.(VA = VRMS X I RMS) |
| Used for | Evaluating heat generated or dissipated and calculating cost of energy. | Properly sizing wires, circuit breakers, and fuses. |
| To add multiple rating together | Add W ratings linearly | No straightforward method to add VA, but if added linearly, result will be greater than or equal to actual total (adding linearly provides a conservative estimate) |
