EZSMART Corporation, ESA/ECRA #7012690 , North York , Ontario
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Often yes — more often than homeowners assume. A 100-amp service is not automatically disqualified from running an EV charger, and in a great many Toronto and GTA homes it handles one with no panel work at all.
What decides it is not the number on the main breaker. It is how much of that 100 amps your home already consumes. This page walks through what actually eats capacity in a typical house, which scenarios work, and what your options are when the numbers come out tight.
A 100-amp service at 240 volts is a meaningful amount of power, and the Code does not require that every appliance be able to run flat out at the same moment. The calculation applies demand factors, because in practice your oven, dryer, and air conditioner do not all peak together.
The loads that consume the most of your capacity, roughly in order:
A home with gas heat, gas hot water, and a gas range uses a fraction of what an all-electric home does. That is why two houses with identical 100-amp panels can get completely opposite answers.
Because an EV charger is a continuous load, the Code requires the circuit to be rated at 125% of the charger’s draw. A 32-amp charger needs a 40-amp circuit. A 40-amp charger needs 50. A 48-amp charger needs 60.
On a 100-amp service that difference matters enormously. Choosing a 32-amp charger instead of a 48-amp one is frequently the entire reason a panel upgrade becomes unnecessary — and in real-world use the practical gap is smaller than the spec sheet suggests. A 32-amp charger adds roughly 200 km of range in an overnight session, which comfortably covers typical daily driving in the GTA.
If the load calculation comes back just over capacity, a load-management device is usually the next thing to price. It monitors total household draw and reduces or pauses the charger whenever other heavy loads run, keeping the service within its rating at all times.
The DCC-9, ChargePoint’s power management, and Tesla Wall Connector load sharing all work on this principle, and they are an accepted method under the Code. For a 100-amp home sitting near the limit, this is frequently the cheapest route to a working charger.
Where it does not help: a panel with no spare slots, or one that needs replacing for safety reasons regardless of the charger.
When the calculation shows the load genuinely exceeds what 100 amps can carry, upgrading to 200 amps is the durable answer. Panel work at EZ Smart starts from $1,599, with the final figure depending on your mast and meter base, overhead versus underground service, panel location, and how many circuits transfer.
It is worth thinking about the next ten years rather than just the charger. If a heat pump, a second EV, or a basement suite is plausible, doing the service once costs considerably less than doing it twice.
Is a 32-amp charger really that much slower?
Less than people expect. It adds roughly 200 km of range overnight against about 300 km from a 48-amp unit. If the car sits from evening until morning, both finish the job.
Can I add a subpanel instead of upgrading the service?
A subpanel solves a shortage of breaker spaces, not a shortage of capacity. If the load calculation is the problem, a subpanel does not fix it.
How do I find out where I stand without committing to anything?
A load calculation takes about fifteen minutes on site and gives a definite answer before you buy a charger. We do this as part of a free assessment.
Does the charger have to be on its own circuit?
Yes. A hardwired Level 2 charger requires a dedicated circuit, and it must be filed with ESA and inspected.
What if my panel is a Federal Pacific or Zinsco?
It should be replaced regardless of the EV question. These makes have known failure issues and many insurers treat them as a liability.
Wondering if your 100 amp panel can support an EV charger? EZSMART provides licensed load calculations and EV charger installation across Toronto and the GTA. Call 416-838-9006, and see what our customers say on our Google reviews page.
Electrician Since 2008 Journeyman Electrician Designated Master Electrician at EZSMART Corp
