What Is a Split-Bus Panel?

What Is a Split-Bus Panel?

A split-bus panel (also called a split-bus service entrance panel) is an older type of electrical panel that has two separate bus sections instead of one main breaker controlling all circuits. The upper section, called the “main” section, contains large 240V breakers for major appliances — typically six or fewer — and one of those breakers feeds the lower bus section, which contains all the 120V branch circuits. Because the lower section is controlled by one of the upper breakers, there is no single main breaker that can shut off all circuits at once from the panel face.

Why Split-Bus Panels Are a Concern

• No single shutoff: turning off power to the entire panel requires identifying and turning off multiple breakers, which is a safety issue during emergencies
• Age: split-bus panels were common in Canadian homes built in the 1960s and 1970s and are now 50+ years old — breakers of this age can fail to trip under fault conditions
• Limited capacity: designed for the electrical loads of their era, they often lack the capacity or circuit count for modern electrical demands
• Insurance issues: many Ontario home insurance companies now surcharge or refuse to insure homes with split-bus panels, citing their age and the single-shutoff limitation

Upgrading a Split-Bus Panel

Replacing a split-bus panel with a modern 200A panel with a single main breaker resolves all of the above issues and typically improves the home’s insurability. Panel replacements require an ESA permit and inspection. EZSMART replaces split-bus panels across Ontario and handles all utility notification, permit applications, and ESA inspections. Contact us for a panel upgrade assessment.

Amir Azimipour

Electrician Since 2008 Journeyman Electrician Designated Master Electrician at EZSMART Corp