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I have an interesting question for anyone willing to answer. Below my electric meter outside there is a breaker box housing the 200 amp main shut off breaker as well as two 20A outside appliance breakers.

There are 3 2AWG aluminum wires leading to a barn about a hundred feet from house through 1.25" underground conduit. These three aluminum wires were not previously hooked up to any breaker on either end of run, but terminate in both breaker boxes. I have since installed two 60A breakers in both breaker boxes, one in the panel below the meter as well as one in the new breaker box in the barn as a main shut off.

The problem is that only one of the two hot wires in barn has power, leaving only one side of breaker box having power, leaving me with only 30A and 110V service at the barn. Are breaker boxes below meters typically only 110V? Any ideas of what could be the problem?

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  • Is the 60-A breaker in the meter panel a 2-pole breaker? I have seen this type of electric panel before and in that case all of the breakers in the outside panel were 2-pole 240 v breakers for a/c, electric dryer, and electric kitchen range. All the breakers in the inside panel were 120 V. If you know how to do it safely, remove the dead front of the outside panel and check the voltage across the two poles of the 60-A breaker that feeds the barn. – Jim Stewart Dec 5 '16 at 2:14
  • I did not get to take off the dead front on the panel I described above to see how the two bus bars are arrannged. In my 45-year-old GE panel one has to note that 2-pole breakers won't work electrically and won't fit in every pair of adjacent slots. I have two columns of 8 one-half inch slots for branch circuits. The panel will not accept 2-pole breakers in positions 1 & 2, but will in 2 & 3, not in 3 & 4, but will in 4 & 5 . . . The reason is that 1 & 2 are on the same leg, 3 & 4 are both on the other leg, etc. If you have to put in a new 2-pole breaker, note that the two poles must be opp – Jim Stewart Dec 5 '16 at 2:34
  • You say only one of the wires in the barn is powered leaving you with only 30 A and 120 V. The voltage between the powered hot and the neutral will be 120 V, but if you have a double pole 60-A breaker in the main panel, you will be able to draw 60 A. If both of the hots are powered and on different legs, you will be able to draw 60 A at 240 V. The barn connection is a sub panel and you do not need a second 60-A double pole breaker there, but only a means of disconnection (which the 60-A breaker will serve), but normally you'd have some smaller breakers in the barn (light, 120 V receptacles) – Jim Stewart Dec 5 '16 at 3:09
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    Obvious question, perhaps, but are all of the Al wires actually connected to the buses in the breaker box beneath the meter? – Craig Dec 5 '16 at 3:52
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Sometimes panel manufacturers will have a null breaker slot on top, bottom, and/or both. Even though a double breaker seemingly fits right in like it's supposed to, only one phase will be hot.

A visual inspection of the busbar is one way to tell, or if you have the busbar layout diagram it will show too.

In case this is the problem, simply move the double pole breaker into the proper slot, then put a blank slot filler to cover the exposed parts. If you don't have a blank handy a breaker with nothing on it is fine too.

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I recently saw an example of the type of electric panel in which there are breakers in the panel outside below the meter, and there are breakers in the panel on the other side of the wall inside. In this instance, all of the breakers in the outside panel were double-pole 240 v breakers for a/c, electric dryer, electric kitchen range, and main breaker. All the breakers in the inside panel were single-pole 120 V.

The house where this panel was installed was a quality house and so I assume this must be an accepted type, but it strikes me as odd that one would have to go outside (maybe in rain or wind storm) to switch off the breaker to these appliances or to shut off the main breaker.

If you know how to do it safely, remove the dead front of the outside panel and check the voltage across the two poles of the 60-A breaker that feeds the barn.

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  • Not only inconvenient for the owner, but seems like a lot of extra work for nothing for the electrician. Really makes you go hmmmmmm – Kris May 11 '17 at 2:01

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