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.

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Here’s links to a collection of our other blog posts about ELECTRIC PANELS:

• What causes copper wires to turn green or black in an electric panel? 

• What is a tandem circuit breaker? 

• When did arc fault circuit interrupter (AFCI) breakers first become required?

• Can an electric panel be located in a closet? 

• What is the maximum number of circuit breakers allowed in an electric panel?

• When should a corroded or damaged electric panel cabinet or disconnect box be replaced? 

 • Can an electric panel be located in a bathroom? 

• Can you add circuit breakers by different manufacturers to an electric panel if they fit?

• My circuit breaker won't reset. What's wrong?  

• What is a split bus electric panel?

• How do I identify a combination AFCI (CAFCI) circuit breaker? 

• What does a circuit breaker with a yellow or white test button indicate? 

• What is the maximum gap allowed between the front of a recessed electric panel box and the wall surface surrounding it? 

• What are the requirements for NM-cables entering an electric panel box?

• Why is a fuse box/panel an insurance problem for homebuyers? 

• Why is bundled wiring in an electric panel a defect?

• What is the difference between GFCI and AFCI circuit breakers? 

• Why are old electrical components not always "grandfathered" as acceptable by home inspectors?

• What happens when you press the "TEST" button on a circuit breaker in an electric panel?

• What is a Dual Function Circuit Interrupter (DFCI)? 

• What is the difference between a Combination Arc Fault Circuit Interrupter (CAFCI) and an Arc Fault Circuit Interrupter (AFCI) circuit breaker?  

• What is the difference between "grounded" and "grounding" electrical conductors? 

• What does it mean when a wire is "overstripped" at a circuit breaker?

• Why is an old fuse panel dangerous?  

• Who is the manufacturer of those "bad" electric panels?

• Why is the circuit breaker stuck in the middle? 

• What is a double tap at a circuit breaker?

• What is the right electric wire size for a circuit breaker in an electric panel?

• What is the life expectancy of a circuit breaker? 

• Why do some breakers in my electric panel have a "TEST" button on them?

• What is the right size electric panel for a house? 

• What do I need to know about buying a whole house surge protector? 

• What is the maximum allowed height of a circuit breaker (OCPD) above the floor?

• What is the maximum height you can mount an electric panel above the floor? 

• What is the code required clearance in front of an electric panel?

• What is the main bonding jumper and where do it find it in an electric panel? 

   Visit our ELECTRIC PANELS page for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles.