Three-phase vs single-phase electricity — what PG and office owners need to know

Tariffs & billing · 7 min read · Updated 2026-04-03
TL;DR

Single-phase serves small room loads (ACs, geysers). Three-phase serves lifts, water pumps, common VRF and commercial. Commercial tariffs are usually billed in kVAh (which includes power factor), so a three-phase meter must read kVAh, not just kWh.

When you need a three-phase meter

  • Connected load > 7 kW (most utilities mandate 3-phase above this).
  • Motor loads — water pumps, lifts, HVAC compressors.
  • Commercial tariff — usually priced in kVAh, requiring a kVAh-capable meter.
  • DG sets above 15 kVA.

kVAh billing and power factor

Many Indian utilities bill commercial consumers in kVAh (apparent energy) rather than kWh (real energy). This penalises poor power factor. A three-phase smart meter like Enlog EnPro measures kWh, kVAh, kVARh and PF, so you can see the penalty and fix it with capacitor banks or APFC.

Frequently asked questions

Can I mix single-phase and three-phase prepaid meters in one PG?

Yes. Encharge deployments typically use Enmate (single-phase) per room and EnPro (three-phase) for common-area, lifts, water motors and DG.

What's a good power factor?

0.95 or higher on the main incomer. Below 0.90, utilities usually apply a penalty. A smart three-phase meter flags low PF in real time.

Related from Enlog

More from Enlog Learn