Basic 101 Circuit Breaker Question?

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Old 11-20-06, 04:01 PM
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Basic 101 Circuit Breaker Question?

Looking in my main panel you've got the single switch breakers for like 15-20 amps etc. I've also got the double switch breakers for 30 amps (green). Two double pole breakers are side by side with a bar reaching from outside switch, to outside switch leaving the two inside switches free. When you turn off the two outside switches all four are forced to trip/switch to the off position.
If each of the green switches have a 30 on each switch, does it mean there is 30 amps from each switch, or 15 each for a total of 30 amps? I'm assuming each switch control 120 volts each for a total of 240 from each double pole breaker if that's the right term for these?

In addition to the above question/s, why is there a bar connecting two of the four side by side switches on two breakers, and why are the outside switches connected to one another vice simply connecitng the two side by side switches? One set controls the dryer circuit, and the other controls what fomerly was an outside 240V feed to a dock until severed with a shovel up near the deck. I have since3 converted it over to a 120V outdoor receptical box.
 
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Old 11-20-06, 05:51 PM
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Originally Posted by Boater59
If each of the green switches have a 30 on each switch, does it mean there is 30 amps from each switch, or 15 each for a total of 30 amps? I'm assuming each switch control 120 volts each for a total of 240 from each double pole breaker if that's the right term for these?
Each "switch" of the double pole 30A breaker provides 30A @ 120V. The two poles together then provide 30A @ 240V. The Amperage is NOT doubled. What is doubled is Watts. 30A @ 120V = 3600W. 30A @ 240V = 7200W.

Originally Posted by Boater59
In addition to the above question/s, why is there a bar connecting two of the four side by side switches on two breakers, and why are the outside switches connected to one another vice simply connecitng the two side by side switches?
You will note that these are "slim" breakers. Two slim (or tandem, or twin) breakers will fit in the place of one single pole full size breaker. In this case, you have two pairs of slim breakers providing two double pole breakers in the space normally occupied by one double pole breaker. This is called a quad breaker. The top two slim breakers on both on the same half of the service. The bottom two slim breakers on on the other half of the service. Thus, to get 240V, you need one of the top slim breakers to be coupled with on of the two bottom slim breakers. In that situation, the inside two are paired up. Sometimes, the outside two are also paired up, thus providing two double pole breakers.

Sometimes, quad breakers only have the middle two breakers paired. This provides one double pole breaker and two single pole breakers.



I'm guessing you have a Murray breaker panel, or at least this quad breaker with green switches is a Murray breaker. If so, I have that same quad in my main panel. The outside pair is problematic from what I see...on mine, I can easily make either switch of that outside pair trip with the other one staying on...not good. Thankfully, that circuit is no longer in use.

From your other post, it sounds like you need to replace the 30A double pole that fed the dock circuit. If indeed you have a Murray panel, look for a Murray QUAD with a double pole 30A in the center and two 20A single pole on the outside I think they make such a beast. If Murray is unavailable in your area, a Siemens should be fine (Siemens owns Murray and their breakers are apparently identical). I know the local Lowes here has a variety of Siemens QUAD breakers with various configurations.
 
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Old 11-21-06, 02:17 PM
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Good info. Makes sense. What I have is actually a Bryant/Westinghouse main panel using Bryant breakers, or at least that's what they say on them. I have another post asking about info for my panel.
 
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Old 11-24-06, 10:39 AM
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I've had another suggestion saying perhaps mine is a Cutler-Hammer model with the BR circuit breakers? I just checked out the Lowes website and they have these type, but I don't see any in the "slim-line" style for making extra space?

Is anyone familar with the Cutler-Hammer BR breakers?
 
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