EV & High-Draw · CEC Section 64 (Renewable Energy)

Solar System Load Calculator

Determine solar AC inverter output, solar backfeed breaker size, and verify against the CEC 120% busbar capacity rule for panel connection.

Solar Inverter AC Rating (kW)

Main Panel Busbar Rating (Amps)

Main Service Breaker Rating (Amps)

CEC 120% Busbar Rule

INVERTER MAX CONTINUOUS OUTPUT

31.7 Amps

REQUIRED SOLAR BACKFEED BREAKER

40 Amp 2-Pole

MAX ALLOWABLE BACKFEED BREAKER

40 Amps

Busbar Rule Compliant: Your 40A solar breaker fits within the 120% busbar limit without needing a supply-side tap.

The 120% Busbar Rule allows total breakers (Main + Solar) to equal up to 120% of busbar rating: (Busbar Amps × 1.20) − Main Breaker Amps = Max Solar Breaker.
Solar backfeed breakers must be positioned at the opposite end of the busbar from the main breaker to prevent busbar overheating.
Solar PV installations in Ontario require microFIT / net-metering approvals from your local LDC (e.g., Elexicon, Hydro One) plus an ESA permit.