Upgrading from 100 to 200 amps: when your panel is too small

Residential · Commercial · Industrial — Montréal, Laval & North Shore

EV charger, spa, heat pump, addition… Is your 100 A service still enough? Here’s how to know, what’s involved, and what to budget — no surprises.

The context

Our homes use more power than ever

Many Quebec homes still have a 100-amp electrical service, sized for the needs of 30 or 40 years ago. Today we plug in EV chargers, spas, heat pumps and power-hungry kitchens. And frankly, when we walk into a house with a 100 A panel, it’s usually an old panel installed back in the day — often at the end of its useful life.

Watch for

The signs 100 A is no longer enough

1

A fuse panel or a rusty service entrance

A fuse panel, or a rusting mast and service entrance, betray the age of the installation. It’s often the sign it’s time to modernize.

2

Breakers that trip

The main breaker or circuits trip when several appliances run at the same time.

3

A full panel

No room left to add a circuit — or “half-breakers” everywhere to squeeze out space.

The triggers

The projects that (almost) always force an upgrade

Some additions demand so much power that they generally require increasing the service capacity:

  • A spa — the most frequent trigger.
  • A pool with an electric heater
  • An EV charging station
A heat pump? Not always. It depends on the load already present in the house. That’s exactly what a load calculation is for: measuring precisely before deciding.
In practice

How long, and how much

In most homes, the upgrade is done in one day, with two electricians. You’re without power for the duration — that day. And above all: we handle Hydro-Québec 100% (the request, coordination, reconnection and seal). Nothing for you to manage there.

$3,500 – $7,000
Realistic 2026 range, installed
1 day
2 electricians · power off for the day

What moves the price: the condition and type of service entrance (overhead or underground), distance, a mast to replace, and corrections found once the panel is open.

  • Load calculation and feasibility check
  • New 200 A panel and service entrance
  • Full coordination with Hydro-Québec
  • Grounding verified and corrected if needed
  • Tested re-energization, to CMEQ and RBQ standards
An option worth knowing

100 A + a load controller: when it’s a real solution

A load controller (load-shedding device) spreads out demand to avoid exceeding capacity — which can, in some cases, avoid a full upgrade. But let’s be honest, it depends on the need:

  • For an EV charger: yes, a load controller works very well and often lets you keep 100 A.
  • For the rest (spa, kitchen, major additions): it’s generally not recommended.
And it has to be said: a 100 A panel is often already old. In that case, it’s better to replace it than to keep patching it. We advise based on your real situation — not the biggest sale.
While the panel is open

What’s worth doing (and what isn’t)

Installing a new panel is the right moment to improve a few things — but not blindly:

  • Surge protector: an excellent idea at installation, to protect your appliances against surges.
  • Grounding: we check it systematically and correct it if necessary.
What about GFCI (shock) and AFCI (arc/fire) breakers? In an older home, circuits are often “mixed.” Adding these breakers blindly would cause nuisance tripping — more trouble than benefit. So we evaluate case by case rather than installing them across the board.
Why Groupe Quenneville

A service entrance done by the book

A residential, commercial and industrial electrical company — CMEQ-certified and holder of an RBQ licence — serving Greater Montréal, Laval, the North Shore, the Laurentians and Lanaudière. We calculate, we coordinate Hydro-Québec, and we guarantee the work.

★★★★★
4.9 / 5 — 249+ Google reviews
CMEQ · RBQ
Certified company
5 yrs
Warranty · $5M insurance
Take action

Is your panel ready for your projects?

We calculate your load and tell you straight whether 100 A is enough or it’s time for 200 A. Free quote.

Frequently asked questions

What homeowners ask us

How do I know if I have 100 or 200 amps?+

The main breaker at the top of the panel shows the amperage (100, 125, 200…). If in doubt, our team checks it and performs a load calculation.

How long does the work take?+

In most homes, one day, with two electricians. You’re without power for the duration of the work — that day.

How much does upgrading to 200 A cost?+

Generally between $3,500 and $7,000 installed, depending on the condition and type of your service entrance. We handle all coordination with Hydro-Québec.

Do I need 200 A just for an EV charger?+

Not necessarily. For a charger, a load controller often lets you keep a 100 A service. That said, if the panel is already old, replacing it is often the wiser move.

Who handles Hydro-Québec and the permit?+

We do. The request, coordination, reconnection and seal with Hydro-Québec are 100% handled by our team.

Groupe Quenneville — Residential · Commercial · Industrial · Montréal, Laval & North Shore
514-503-1353 · groupequenneville.com

Sources: CMEQ · Hydro-Québec · RBQ.