kVA Explained: A Simple Guide for First-Time Generator Buyers in Assam
Every generator quote you receive in Assam is written in kVA, and almost every appliance you own is rated in watts. That mismatch is where first-time buyers get lost. Here is the whole thing in plain language.
kVA versus kW
kW is the real power that does useful work — the heat in a kettle, the turning of a motor. kVA is the apparent power the generator must supply, which includes the extra current that inductive loads like motors and ACs pull without converting into work. Generators are rated in kVA because that's the electrical burden they actually carry.
The conversion
The two are linked by power factor, typically 0.8 for a diesel generator:
- kW = kVA × 0.8 — a 62.5 kVA set delivers about 50 kW.
- kVA = kW ÷ 0.8 — a 20 kW load needs about 25 kVA.
Worked example for a Guwahati shop
Say your load is 8 kW: lighting, two ACs, a fridge and billing systems. Divide by 0.8 and you need 10 kVA. Add roughly 25–30% headroom for motor starting current and future growth, and a 12.5 kVA set is the sensible buy.
Why headroom is not upselling
Motors draw several times their running current for a moment at start-up. Without headroom the set trips, and repeated tripping damages the alternator. But over-sizing has its own penalty: a generator running below about 30% load for long periods suffers wet stacking, fouling the exhaust and injectors. The target is loading of roughly 60–80%.
Other numbers on the quote
- Standby vs prime rating: standby is for occasional backup; prime is for regular running at variable load.
- Single vs three phase: anything with three-phase motors needs a three-phase set.
- Fuel consumption at 75% load: the figure that actually decides your running cost.
Still unsure?
You don't have to do the arithmetic alone. We run a free load survey anywhere in Guwahati and across Assam, measure your real consumption and recommend a rating with the reasoning shown.
Talk to Mecwel Engineers in Guwahati
We've been Assam's authorized Greaves Cotton dealer since 1991. Send us your requirement on WhatsApp and we'll reply with the right DG set, price and service plan — or call +91 97060-11988.