Transformer installation, maintenance & replacement in Toronto.
When your equipment and your building run on different voltages, a transformer is what makes them work together — and when a service needs to feed a whole building, a transformer is what makes that possible. 3e Electrical installs, maintains and replaces step-up and step-down transformers for commercial and industrial sites, engineered in-house and installed by licensed ESA electricians.
One device between your service and everything it feeds
A transformer changes voltage — up or down — so power arrives at the level each part of your building actually uses. In Toronto and the GTA it does two jobs, sometimes in the same building:
Feeding the whole building
Many commercial services arrive at 600V. Your lighting, receptacles and most equipment run on 120/208V three-phase. A step-down transformer takes the 600V service and produces the 120/208V distribution that feeds your panels — one transformer can carry an entire building, a tenant floor, or a production area.
- 600V service in, 120/208V three-phase out
- Feeds distribution panels, lighting and receptacles
- Sized to the building’s real load, with room to grow
Matching a machine’s voltage
Equipment is built for the voltage it was designed around — a machine wound for 480V, or imported equipment expecting a different supply than your building offers. A dedicated step-up or step-down transformer at the equipment makes it run on your service, correctly and safely.
- Step-up when equipment needs more than the building offers
- Step-down when equipment needs less than the service delivers
- Common on manufacturing, HVAC and process equipment
Transformers rarely fail quietly. They warn you first.
Most transformers give years of service, then start talking. These are the signs we get called about — every one of them is worth a look before it becomes an outage:
Age
Many units in GTA buildings are 25 to 40 years old — at or past their design life. Age alone doesn’t condemn a transformer, but it puts it on the watch list.
Heat & discoloration
Running hot, discoloured paint or insulation, or a hot smell near the unit points to overload or breakdown inside. Thermal scanning finds hot connections before they fail.
Noise & vibration
A hum that has grown louder, changed pitch, or started buzzing through the structure is a classic early warning of core or winding problems.
Oil leaks (oil-filled units)
Weeping seams, low oil, or oil on the pad on a liquid-filled transformer means the cooling and insulation system is compromised. It needs service, not patience.
Capacity limits
Adding machinery, EV charging or a tenant and finding the transformer is the ceiling? Undersized units run hot and shorten their own life. We review load and options.
Tripping & power quality
Nuisance trips, flicker under load, or equipment behaving badly on one distribution can trace back to a tired transformer or its connections.
Looked after, a transformer outlives the building’s plans
Transformer maintenance is unglamorous and cheap next to an emergency replacement. Our maintenance visits cover:
Inspection & thermal scanning
Infrared scanning under load finds the hot lug, the loose connection, the overloaded phase — while it’s still a work order, not a shutdown.
Cleaning & connections
Dust and debris cleared, vents open, connections checked and torqued to spec. Heat is the enemy; airflow and tight connections are the defence.
Oil testing (oil-filled units)
Oil sampling and analysis shows insulation condition and internal faults developing inside liquid-filled transformers — the earliest warning you can get.
Load & capacity review
We compare what the transformer carries against what it should, and tell you plainly how much headroom you have for new equipment or charging.
Planned, permitted, and scheduled around your operation
Site review & load check
We read the nameplate, measure the load, and confirm the voltages on both sides — the facts the whole job hangs on.
Engineering & ESA permit
Our in-house principal engineer sizes the unit and designs the installation. ESA permits and inspections are arranged by us.
Install or replace
Replacements are planned shutdowns — nights or weekends where your operation needs them — so the building is without power for hours, not days.
Test, commission, document
Energized, tested under load, and documented: nameplate data, test results and maintenance notes your facilities team can file.
We do this work for manufacturing plants, warehouses, commercial buildings, institutions — and for fleet depots, where transformers and service capacity decide how many vehicles can charge. See how it fits together on our fleet EV charging page, or the full range on our commercial electrical services page.
Common questions about transformers
Do I need a step-up or a step-down transformer?
It depends on the two voltages you’re connecting. If your equipment needs a higher voltage than your building supplies, that’s step-up. If it needs lower — like a 600V service feeding 120/208V panels — that’s step-down. Tell us the nameplate voltage of the equipment and your service size, and we’ll tell you which one and how big.
Can one transformer feed my whole building?
Yes — that’s the normal arrangement in many Toronto commercial buildings. A single step-down transformer takes the 600V service and produces the 120/208V three-phase distribution for the building’s panels. Whether yours is sized for it is a load question, and that’s the first thing we check.
Will we lose power during a replacement?
Briefly, and on your schedule. A replacement needs a planned outage while the unit is swapped — we schedule it overnight or on a weekend for most sites, do the changeover in hours, and test before handback. Buildings that cannot go dark at all can be supported with temporary power planning.
What’s the difference between dry-type and oil-filled transformers?
Dry-type units are air-cooled and common indoors. Oil-filled (liquid-filled) units use oil for cooling and insulation, are common at larger sizes and outdoors, and need oil testing as part of maintenance. We install and maintain both.
Do you maintain transformers you didn’t install?
Yes. Most of our maintenance work is on existing units — inspection, thermal scanning, cleaning, connection checks and oil testing, with a written report of what we found and what it means.
Do transformer installations need a permit?
Yes. Transformer work is electrical work under the Ontario Electrical Safety Code — it requires an ESA permit and inspection, and it must be done by a licensed electrical contractor. Ours is ECRA/ESA licence 7014948, and permits are part of every project we run.
Let’s talk about your transformer.
Tell us the two voltages you’re working with — what you have, and what your equipment or building needs — and we’ll map out the right unit and a clean install plan.
647-560-7995We are among the best in the business.
3e Electrical Construction · Licensed ESA electricians (ECRA 7014948) · Serving Toronto, Etobicoke, Mississauga, Brampton and the GTA
