240v circuits??

[Brian Fulkerson]

Is it safe to say that a 240v circuit breaker is rated for 40amps if the switch has two 20amp switches tied together?

If the amperage raises above 20 amps, will one half of the breaker blow?

I hope I am phrasing this question properly...

Brian

[Jason Beam]

No. It's rated for 20amps at 240v. Assuming it's a real 240v breaker with the tied legs (like it should be), if either leg of the 240v line raises above 20amps, they will both blow.

[Steven DeMars]

If you have a piece of equipment that requires 220VAC with a 40 amp breaker, what you need is a double breaker with both throws factory tied together . . . That means BOTH sides of the breaker will say "40". Now you can not just simply pull a double 20amp breaker and replace it with a double 40 amp.

You must replace or install a conductor (wire) that can handle that amperage. You will probably need to run an 8 gauge conductor. The existing 20 map probably has only 12 gauge.

Just sit back and monitor your post for replies. You will get tons of answers. A lot of these guys are very knowledgeable, some are not.

Based on your question, I would say you definitely need an electrician.

[Mike Cutler]

Is it safe to say that a 240v circuit breaker is rated for 40amps if the switch has two 20amp switches tied together?

If the amperage raises above 20 amps, will one half of the breaker blow?

I hope I am phrasing this question properly...

Brian


The short answer is no.
A 240 40 amp breaker is rated to safely carry up to 40 amps on each pole.
The actual electrical trip mechanism "tie" is internal to the breaker. The bar that you see across the breaker is for the convenience of opening both poles safely, as long as it hasn't been messed with.
One half of the breaker does not trip independent of the other in a properly functioning breaker. Either pole will open the other pole internally.

If your actual question is. Can two single 115/ 20 amp breakers be physically tied together with a nail through the breaker switch(s) to give one 40 amp 240 breaker? The answer is no. Yes I have seen this done.

[Eric Haycraft]

If your actual question is. Can two single 115/ 20 amp breakers be physically tied together with a nail through the breaker switch(s) to give one 40 amp 240 breaker? The answer is no. Yes I have seen this done.

I want to clarify something here. If you tie two 120 volt 20 amp breakers together at opposite poles (which should not be done by the way) it will yield one 240 volt 20 amp circuit. On american 240, the current flows from one pole to the other and reverses itself 120 times a second, therefore the maximum current would still be 20 amps. You would be able to run double the power through this circuit (power = current * voltage), but the total current for any pole could not exceed 20 amps. Again, wiring it this way is a bad idea since one pole could blow while leaving the other hot. It would also be easy to forget to switch both off one of the breakers when performing service and electrocute yourself. Stick to the two pole breakers. If you wanted to yield a single 40 amp 240, you would need two 40 amp 120 volt breakers...again don't do this and go with the two pole breakers.

[Mike Cutler]

Eric

I was kinda trying to avoid going that level. I've seen this question before, not here, and I've seen a person's unique solution also.
Wasn't as good as the neutral being hose clamped to a water pipe, another ingenius solution for a MacGuyver type Edison circuit. Which was made really interesting when the panel ground on the same water pipe got lost, and the person was shocking themself while washing the car.:eek:

[Mark Engel]

:rolleyes:

[scottj owen]

Sounds like you only have 20 amps, secondly a 220 volt breaker requires a strap by code ,so both legs are turned off together. All the best.