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Commercial and industrial switchgear
Shop, warehouse or plant: what a building’s main service equipment includes, what changes at 347/600 V, the maintenance standard and the shutdown to plan.
In short
In a shop, a warehouse or a plant, the main service equipment receives Hydro-Québec’s supply, then cuts or distributes it throughout the building.
- Hydro-Québec’s low voltage is offered single-phase at 120/240 V or three-phase at 347/600 V.
- The CSA Z463 standard covers the maintenance of electrical installations, new and existing.
- Transformer-rated metering is reconnected by Hydro-Québec: the shutdown date is decided with Hydro-Québec.
- How long without power? For a business, plan on about 24 hours with us, as a rule; in an apartment building, usually about 6 hours.
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What it includes
Hydro-Québec’s Blue Book lists, among the customer’s service equipment, the transformer cabinet, the splitter box, the service box, the disconnecting means and the meter base.
The splitter box is where the feeders are connected; the disconnecting means is what cuts the current in a circuit.
For an apartment building, see apartment building switchgear replacement.
347/600 V: what changes
Hydro-Québec offers low voltage single-phase at 120/240 V or three-phase at 347/600 V.
At 347/600 V, the meter sits on a meter base up to 200 A; above that, it is connected to voltage and current transformers.
Power is supplied directly from the line if the service boxes add up to 600 A or less, or more if the maximum demand stays under 500 A.
Hydro-Québec may accept an additional service dedicated to a fire pump or a life safety system.
When several services feed the building, their service boxes are grouped where possible; otherwise, a permanent diagram on each one shows where the others are.
Maintain or replace
The CSA Z463 standard sets requirements for the maintenance of electrical equipment and installations, whether new or existing; its 2018 edition has been replaced by CSA Z463:24.
Its purpose is safe, reliable and cost-effective operation through consistent maintenance practices, with people’s safety first.
Any added load means recalculating the feeders and the service located upstream.
Switchgear to replace?
We examine the switchgear and the capacity; the price is written in the quote, at no charge.
Send my quote requestPlanning the shutdown
The master electrician is not allowed to reconnect transformer-rated metering: Hydro-Québec does it, and the date is planned with Hydro-Québec.
The electrician can only disconnect and reconnect the overhead service themselves at 120/240 V, 200 A or less, with Hydro-Québec’s prior authorization.
When the load moves from an old service to a new one, the two cannot be connected at the same time.
We split the work into stages so the business keeps its doors open as long as possible.
For a business or a plant, the shutdown typically runs around 24 hours with us; for an apartment building, around 6 hours.
What we do
Our master electricians work for residential and commercial customers, and also do industrial work.
Switchgear and meter stacks are the commercial work we especially do.
The service request and the declaration of work are filed with Hydro-Québec by the master electrician.
Frequently asked questions
What does a commercial building’s main service equipment include?
What cuts and distributes the power where it enters the building: disconnecting means, service box, splitter box, and the transformer cabinet if there is one.
Is there a maintenance standard?
Yes: the CSA Z463 standard sets maintenance requirements for electrical installations, new or existing.
Can the business stay open during the work?
We split the work into stages as much as possible; the shutdown itself usually lasts about 24 hours.
Who reconnects after the work?
Hydro-Québec, when the meter is transformer-rated: so we agree on the date with Hydro-Québec.
What voltage for a commercial building?
Hydro-Québec offers low voltage at 120/240 V single-phase or 347/600 V three-phase.
Switchgear to replace?
We plan the shutdown with you and with Hydro-Québec, with the price written in the quote.
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Get a quote: commercial or industrial building
Sources
Consulted on October 29, 2026.