How To Look At A House
McGarry and Madsen's home inspection blog for buyers of
site-built, mobile/manufactured and modular homes
Can I use a 240-volt (double-pole) breaker for 120-volt circuits?
Sunday, May 29, 2022
There are no code restrictions we know of that would keep you from using a double-pole 240-volt breaker for one or two 120-volt circuits. But there are several limitations:
1) The 120-volt circuit wiring and connected loads must match the amperage rating of the breaker. You cannot, for example, use one leg of a 240-volt 50-amp breaker formerly for an electric range when switching it out for a gas range that requires a 120-volt circuit for the piezo-electric starter. That would need a 15 or 20-amp rated breaker (per manufacturer’s instructions).
2) Most 240-volt breakers have an "internal common trip.” This means that, if either 120-volt leg has an overcurrent event, a connection inside the breaker will cause both sides trip. Removing the switch connector toggle for this type breaker will not allow each side to act independently. The breaker may—or may not—be marked as INTERNAL COMMON TRIP or NON-COMMON TRIP, so you might have to refer to the manufacturer’s spec sheet to determine which type it is. This is not a problem if you are only using half of the breaker for a single 120-volt circuit.
3) Removing the switch connector toggle may not be possible without damaging some breakers, and a damaged breaker cannot be used.
• • • • • • • • • • • • • • • • • • • • • • • • • •
Here’s links to a collection of our other blog posts about ELECTRIC PANELS:
of Blog Posts
Top 5 results given instantly.
Click on magnifying glass
for all search results.
Buying a home in North/Central Florida? for a team inspection by two FL-licensed contractors and inspectors. Over 8,500 inspections completed in 20+ years. In a hurry? We will get it done for you.