Key takeaways
- Three-phase power delivers smoother, more efficient power for motors and heavy equipment.
- Common commercial services in Canada are 120/208 V and 347/600 V three-phase.
- Adding three-phase service involves your utility, so plan early in a fit-out or equipment purchase.
If you are opening a restaurant, setting up a shop or buying new equipment, you will hear the term three-phase power. Here is what it means and how to tell if your business needs it.
Single-phase versus three-phase
Most homes use single-phase power: one alternating current waveform, delivered at 120/240 V. Three-phase power uses three waveforms offset from one another, so power delivery never drops to zero. The result is smoother, more efficient power, especially for motors.
Common commercial voltages
- 120/208 V three-phase is common in retail units, offices and restaurants.
- 347/600 V three-phase is common in larger commercial and industrial buildings, often with transformers to supply 120/208 V loads.
Equipment that often needs three-phase
- Large HVAC and refrigeration equipment
- Commercial kitchen equipment
- Machine tools, compressors and welders
- Elevators and large pumps
- Some commercial EV chargers
Check the equipment nameplate or specifications for voltage and phase before you buy.
Does your unit have three-phase?
Look at the main panel or switchboard label, or ask your landlord. An electrician can confirm the service type, size and remaining capacity during a site visit.
Adding or extending three-phase power
If your building already has three-phase service, extending it to new equipment is usually a matter of new feeders, panels and circuits. If it does not, a new or upgraded service involves your local utility and can take time, so plan it early in a fit-out or equipment purchase.
Planning a fit-out?
We work with business owners, landlords and general contractors across St. Catharines, Niagara Falls, Welland and the region on fit-outs, equipment wiring, lighting retrofits and service upgrades. See our commercial electrical service or call (905) 931-4522.
Frequently asked questions
How do I know if my building has three-phase power?
Check the label on the main panel or switchboard, or ask your landlord. An electrician can confirm the service type and capacity.
Can I run three-phase equipment on single-phase power?
Sometimes with a phase converter, but it is not ideal for every application. Talk to an electrician and the equipment supplier before buying.
