Dear Readers, I=92ve a 220 water pump for the house that, when I trace back to the main circuit breaker box, is connected to two (2) individual 15Amp breakers located immediately adjacent to each other (one on top of the other). I confirmed that tripping any single one will still leave a live 110 feed to the pump. This is obviously not safe and I suspect I need to either: connect the two breaker throws together (if such an add-on connector exists), or purchase a double wide breaker with two poles (if such a breaker exists). Do either of these "solutions" exist?
The way it is now is fine, I would not lose sleep over it. Whats important is as long as the circuit opens if there is a problem, does not matter which breaker opens. Even though 1 leg is still live, it is still protected by its own respective breaker. Of course if you ever have to work on the pump, you have to remember to shut both breakers off. I have a 220V A/C in a condo that is protected by 2 individual 15 breakers, no problems. If you like to replace with a 2 pole 15A breaker to simplify things, you may.
I disagree, I think the OP should replace the two breakers with a single 240V breaker (basically two single pole breakers in a unit, with the handles tied together. Fortunately this is fairly inexpensive and easy unless he has an unusual/old breaker box. Typical breakers are readily available at a big box (Cutler-Hammer, GE, Siemens/ITE, Square D etc.) or electrical supply, and a 15A double pole breaker shouldn't run more than $30-40.
On some breakers you can tie them together with a nail or screw through the existing holes in the sides of the handles. You may be able to get the tie bars at a store, but it may be easier to just replace the breaker with the 2 pole for about $10. I would check the amp rating on the pump to verify that the 15 Amp breaker and wiring are large enough. 15A >= 14ga, 20A >= 12ga, 30A >=10ga. The pump also should be no more than 80% of the breaker size.
I must disagree. The way it is, not fine. If one breaker goes off, the pump stops. A worker might think the power is off, but the pump is still "hot".
And like you say "you have to remember....." which is dangerous. I vote to get the double breaker, and be safer than it is now. For your AC, and for the fellow's house pump, also.
Sorry if this is a dumb question: if they are physically tied together with a tie bar, and (somehow) a single breaker trips, will the trip throw the switch hard enough to force the other breaker to switch off together with it??
Yes. That's the reason they are tied together. So that if one side over loads, both will shut off. And then the appliance will be "cold" or unpowered.
No, not always. There's a difference between a double pole breaker, where the two sides are internally connected, and two single pole breakers with a handle tie. In both cases, if you manually turn off the breaker (you are using it as a disconnect), you will turn off both sides. But as far as automatic operation (its job as an overcurrent protection device), only the double pole breaker will reliably shut off both sides.
For the OP, you need at a minimum to have the proper handle tie (no nails!), and you may need to have a double pole breaker. I believe that if the pump uses the neutral, you need a double pole breaker; if it is a pure 240V load without using the neutral, then a handle tie is sufficient. I've quoted the appropriate parts of the NEC below (2002 version). I'd just put in a double pole breaker, anyway, as it seems safer.
Cheers, Wayne
240.20(B) "Circuit Breaker as Overcurrent Device." Circuit breakers shall open all ungrounded conductors of the circuit unless otherwise permitted in 240.20(B)(1), (B)(2), and (B)(3).
240.20(B)(2) "Grounded Single-Phase and 3-wire dc Circuits." In grounded systems, individual single pole circuit breakers with approved handle ties shall be permitted as the protection for each ungrounded conductor for line-to-line connected loads for single-phase circuits or 3-wire, direct current circuits.
Where I used to live, I had a similar situation. Those breakers had holes through the handles and I installed a bolt between them, then verified that tripping one would turn the other off too.
Hey Stormy, That's why they make volt/amp/ohm meters. Only you would be dumb enough to stick you hand in something that you didnt test first. Maybe you outta buy a better meter than that $1.99 Harbor Freight Indonesian model. Bubba
No! Dumbass! They dont ALWAYS trip them both. Thats whats supposed to happen but doesnt always. Especially on an older or weak breaker. Time to bash your head in again. Bubba
What breakers, other than a main, are 'tied' internally? I've never seen one.
Whats the electrical difference between a double pole breaker and 2 breakers with the handles tied together? We are not talking about a double pole switch where the hots and neutral are all switched are we?
The difference is that in a 2 pole breaker, the trip mechanisms are tied together internally and will both trip if the unit sense an overcurrent. For two single breakers with a handle tie, this is not reliably true.
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