any important difference between a 120/240v breaker and a 240v breaker?

[benjunk]

I'm installing a subpanel fed from a 2-pole 60A breaker over 6/3 romex. I picked up the breaker (a Square D QO) and after I got home realized it says 120/240v. Is there any difference this and a breaker that is just 240v?

[Terry]

No

[RBM]

I would imagine all double pole breakers are 120/240 except for certain GFCI models. In any event, you are using it as a 120/240 volt feeder main for your sub panel, so you've got the right thing

[Stormin Mormon]

One costs half as much to operate.

And if you believe that, I've got some oceanfront property to sell you.

[benjunk]

thanks everybody!

[Joseph Meehan]

Define important?

[Tom Horne]

There is a difference between the two breakers but it is unimportant in your application. A breaker that is listed for 240 volts can be used in circuits having 240 volts relative to ground. A 240 volt, corner grounded, Delta connected supply for refrigeration equipment in a restaurant comes to mind. A 120/240 breaker can not be used in circuits having a voltage to ground higher than 120 volts nominal but it can be used in circuits having 240 volts between the ungrounded current carrying conductors. In your application either breaker is fine but the

120/240 volt one is undoubtedly cheaper.

-- Tom Horne