Breaker box question

[boomhower]

I am looking to install, or have installed, an interlock kit for my generator. I took a look at my breaker box and it has a breaker I have never seen before. For the interlock kit the top right two slots have to be available to install a 30 amp breaker that brings in power from the generator. By box has a 50 amp breaker that stretches across both sides of the box, I've never seen such a thing. I can put swap a breaker but have no clue what this is or what to replace it with to free up the space I need. If I need a pro what would be a rough estimate to get it done? Here is a link to a photos of the set-up. http://imgur.com/a/VKO91

 

[NutBucket]

IMHO pull the cover off and see what that huge thing actually is. I don't think I've ever seen a breaker that spans both sides like that.

 

[boomhower]

IMHO pull the cover off and see what that huge thing actually is. I don't think I've ever seen a breaker that spans both sides like that.

Scroll down the link and there are several pictures of it.

 

[NutBucket]

Doh! Stupid me for not scrolling.

IMHO an easy answer might to shift the breakers down to make room for the interlock kit.

 

[NutBucket]

Had to add that I LOVE the simplicity of this interlock; no need for an additional panel or any of that jazz. Well done Square D!

 

[boomhower]

Doh! Stupid me for not scrolling.

IMHO an easy answer might to shift the breakers down to make room for the interlock kit.

Genius. Take the cover back off and see if there is enough slack in the wires. That should make for an incredibly easy solution.

 

[NutBucket]

Another solution might be to replace that double breaker with a "standard" breaker like the one below it. I really can't figure out why that breaker is so large.

 

[boomhower]

Another solution might be to replace that double breaker with a "standard" breaker like the one below it. I really can't figure out why that breaker is so large.

It says on it 120/240. It is for the A/C. Outside there are two breakers, one 60 and one 40. Marked heat and emergency heat. That huge one is the breaker box is a 100 amp if that helps at all. It seems two breakers outside feeding one big one side.

 

[NutBucket]

All of those breakers are 2-pole. There are lots of 2-pole breakers that are 100 amp. From what I can gather that big one might be a "main service" type. Maybe the electrician didn't have the smaller ones in his truck?

 

[boomhower]

In theory could just plop this in to replace it?

 

[NutBucket]

In my opinion yes.

If it was my house I'd do it. But since its your house it's just an opinion

 

[boomhower]

In my opinion yes.

If it was my house I'd do it. But since its your house it's just an opinion

I think that's the route I'm going to take. Easier than moving every single breaker in the box. I've work for a city and will run it by some of the electrical guys just to make sure but that is my plan at the moment. Thanks a bunch NutBucket.

 

[NutBucket]

You're welcome. I love it when there is an easy solution.

 

[stormkroe]

OP, first off, there's no antioxidant on those aluminum wires going into that top breaker, I would put some on before doimg anything. Second, that breaker is that big because the bus bars aren't rated for 100 amps, so it spans 2 of them to meet the requirement. The large part of it on the right side is probably inert, as it will just be to fill in the panel knockouts.
Now, my main question is, why do you have to install your generator breaker in the top right? The bus bars alternate phases all the way down the panel, but are parallel with each other, i.e., the bottom right position is exactly the same as the top right, middle right, left, etc.

 

[herm0016]

OP, first off, there's no antioxidant on those aluminum wires going into that top breaker, I would put some on before doimg anything. Second, that breaker is that big because the bus bars aren't rated for 100 amps, so it spans 2 of them to meet the requirement. The large part of it on the right side is probably inert, as it will just be to fill in the panel knockouts.
Now, my main question is, why do you have to install your generator breaker in the top right? The bus bars alternate phases all the way down the panel, but are parallel with each other, i.e., the bottom right position is exactly the same as the top right, middle right, left, etc.

Most of the interlock kits have a plate or some sort of lock to lock out the main. Main is at the top and the plate usually only fits in one place on the panel.

 

[NutBucket]

I thought the buss bars were usually rated quite a bit more than the service?

 

[stormkroe]

I thought the buss bars were usually rated quite a bit more than the service?

The entire bus is, but the individual 'tabs' or other point of attachment for individual breakers are often limited, especially in an older panel. 70 amp max was pretty common not too long ago.

 

[boomhower]

The entire bus is, but the individual 'tabs' or other point of attachment for individual breakers are often limited, especially in an older panel. 70 amp max was pretty common not too long ago.

This is older, house was built in 1979.

 

[natto fire]

stormkroe is absolutely correct. OP, are you sure that is the only panel in your house, and how old is your HVAC equipment?

A 100 amp breaker and aluminum conductors makes me think there is a subpanel. Also, most newer HVAC equipment calls for copper conductors. I suppose it could be aluminum to the disconnect and copper to the unit.

That said, 100 amps is quite a bit of current, and if you are using the original furnace (which must have/had 15+ kW resistive elements) I would hate to pay your electric bill assuming you live where it is very cold.

 

[boomhower]

stormkroe is absolutely correct. OP, are you sure that is the only panel in your house, and how old is your HVAC equipment?

A 100 amp breaker and aluminum conductors makes me think there is a subpanel. Also, most newer HVAC equipment calls for copper conductors. I suppose it could be aluminum to the disconnect and copper to the unit.

That said, 100 amps is quite a bit of current, and if you are using the original furnace (which must have/had 15+ kW resistive elements) I would hate to pay your electric bill assuming you live where it is very cold.

This is the only panel in the house. Their are two breakers outside by the HVAC but that is it. The HVAC was replaced a few years before I moved in, I'd say around 2005. Heat of summer and dead cold of winter the bill hit $300, spring and fall $150.

 

[natto fire]

This is the only panel in the house. Their are two breakers outside by the HVAC but that is it. The HVAC was replaced a few years before I moved in, I'd say around 2005. Heat of summer and dead cold of winter the bill hit $300, spring and fall $150.

Sorry to go further off topic, but how many square feet of climate controlled space?

As far as the breaker and HVAC "sub" I am wondering if you can now downsize that 100A breaker if the load has reduced through the newer HVAC equipment.

Not sure if you ran this by your electrical friend or not, but if you determine the load is much lower, you can switch to a normal two pole QO breaker, and just land your aluminum conductors on that. Assuming they will fit on the new breaker. Those should be #1 or 2/0 wires, which might not fit on a 60A breaker.

 

[paperfist]

This is older, house was built in 1979.

That's not old lol

The entire bus is, but the individual 'tabs' or other point of attachment for individual breakers are often limited, especially in an older panel. 70 amp max was pretty common not too long ago.

70 amps for the whole service?

 

[Micrornd]

70 amps for the whole service?

Not the service.
He's referring to any breaker other than the main.
All panels, anywhere downstream of the main breaker, limit the ampicity of the breakers because of the size of the lugs that those breakers clip on/attach to.