How to Tell If a House Has 3-Phase Power

How to Tell If a House Has 3-Phase Power

Nearly all Ontario residential properties are served by single-phase power, not 3-phase. Single-phase residential service delivers two hot legs (each 120V to neutral, 240V between the legs) from the utility. Three-phase service is common in commercial and light industrial buildings and is occasionally found in large rural properties or hobby farms where heavy equipment requires it. The easiest way to tell if a property has 3-phase service is to look at the service entrance and the panel.

How to Identify 3-Phase vs. Single-Phase

• Look at the utility meter: a single-phase meter has two service entrance conductors entering it; a 3-phase meter has three
• Look at the main panel: a single-phase 200A residential panel has two bus bars; a 3-phase panel has three — and the main breaker will be a triple-pole breaker
• Check the service entrance cable at the weatherhead: single-phase has two hot conductors and one neutral; 3-phase has three hot conductors and a neutral
• Contact your utility: Hydro One or your local LDC can confirm the service type for your address

Why It Matters

Most residential appliances and devices only require single-phase power. If you are adding equipment that needs 3-phase — such as a commercial air compressor or elevator — a Licensed Electrical Contractor must apply through your utility to upgrade the service. EZSMART handles service upgrades, panel replacements, and utility coordination across Ontario. Contact us if you are unsure what service type your property has.

Amir Azimipour

Electrician Since 2008 Journeyman Electrician Designated Master Electrician at EZSMART Corp