Weird breaker panel question...

[TNToy]

Most of you probably saw my previous post about installing a sub-panel in the garage to power everything out there.

Well, I started checking everything out this morning to go price everything at Home Depot, Lowes, and the local hardware place... and this is really weird.

Okay. Here's a picture of the main breaker panel in our home. Background: This house was built in '78 and has no aluminum wire, so at least I didn't have to contend with that. But EVERYTHING in this place is electric. Not only is it all electric, but there are no gas lines. Usually in a home with electric major appliances, you'll find a capped-off gas line here and there. I don't have a single gas line in my house.

So electric loading is significant. Electric dryer, heat, water heater, and whatnot have all been running at the same time.

First step was to go look outside. No breakers. Popped the cover off of the meter just in case they weirdly stuck the main breaker in there. Just large cables coming up out of the ground, to the meter, and then fed through 1.5" conduit through the wall, and straight into the back of the main panel.

Now here's a picture of the main panel with the cover on, so you can see which breaker is which:

Note that, above, the breaker labeled "main" is 60 AMPS!... and then, two above it, is the heat pump's breaker. 100 AMPS.

No big deal, they just mixed up the labels, right? Okay. Now things get weird... Here's the cover off the panel:

The orange-handled breaker is the 'main' one. It's output feeds some portion of the rest of the box, I guess? The output from that breaker loops around and connects to the feeders running down the center of the box. Here's a close-up:

And while I'm at it, here's a closer shot of all the breakers showing what everything is rated:

So I guess I have two questions:

(1) Is this some type of weird panel, where all the major appliances are up at the top, and the 'main' only operates the bottom half of the panel, with lights and receptacles fed by it?

If that's so, then...
(2)How do I figure out what my service is rated?

(3)How do I cut power to the whole panel to safely wire in the 100A subpanel? I can't get around the fact that the feeders from the street are always hot, but can it seriously be set up so that there's no way to kill power to the main rails down the center of the box?

(4)Where do I install a 100A double-pole breaker? My plan all along has been to swap a couple of 20A receptacle breakers out for slim-line ones, and make the space I need for a double-pole breaker. If those are actually fed off of the 60A "main" breaker... that's not going to work.

What the heck is going on here?

I know there's no way I've got 100A service. The heat pump, oven, and dryer all running at once would pretty much consume that whole quota...

 

[W-Cummins]

That is a split bus box, used to be common, I do not think that they are made any more.

The top part of the box acts like a main lug box ( no main breaker) and the larger breakers are installed in it, The lower part of the box is run off one of the breakers on the top half of the box ( the 60 amp?? )

You may well only have a 100 amp service.

You can not turn off the top part of the box unless you pull the meter out side.

You can not install a 100 amp breaker in the lower part of the box and feed it from the 60?? amp lower feed and you have no open spaces in the upper part of the panel)

If that is a 60amp breaker feeding the lower bus you may be able to replace it with a 100 amp _IF_ the lower bus is rated at 100 amps.

William....

 

[TNToy]

Okay. That makes sense out of what I've got. Never heard of those.

Assuming the box will take 100A in the bottom... uh...

If I were to slap a 100A breaker in there (and possibly upgrade the wire size feeding the lower portion of the panel) and then use THAT to feed ANOTHER 100A breaker for the sub-panel...

Can you do that? It just seems weird to have a 100A breaker stacked behind another 100A breaker...

I will say, however, that I don't think capacity will be an issue. Actual load in the garage most of the time will be 25 amps with one 5A powertool going, and 45 with either the compressor or welder running, by my best calculations.

So I don't think capacity will be an issue. I'm just planning for a 100A breaker because I'd like to:

Run 75-85 feet of #2 wire to the subpanel in the garage, and have 20A breakers for:
1. Welder (220V)
2. Compressor (220V)
3. Lights and heater
4. Outlets #1
5. Outlets #2

 

[TNToy]

For that matter, how on earth could I have 100A service? I mean, a heat pump, dryer, and range all going at once will use a good bit of that right?

I guess I tend to judge things by their breakers. A clothes dryer on a 50A breaker probably doesn't actually pull more than 25-30 amps, does it?

 

[Charles (in GA)]

This whole thing looks like someone's homebrewed engineering. The way one of the wires from the "main" connects to the buss strip on the lower RH side with that screw doesn't look right at all. Personally, I'd rip out the whole thing and put in a new panel with a main breaker at the top (or bottom, it is generally OK to install a panel "upside down") and start over. This looks like an electricians nightmare.

Charles

 

[wilbilt]

Wow...that's crazy.
I know that feeding the bus bars directly from the meter without a fused disconnect / breaker would never fly around here.

 

[Charles (in GA)]

Wow...that's crazy.
I know that feeding the bus bars directly from the meter without a fused disconnect / breaker would never fly around here.

No, most places it wouldn't, but according to the NEC you can have up to six disconnects without a single controlling main. The NEC basically requires that you not have any more than six movements of the hand to shut everything off.

Personally, I like the idea of an outside disconnect, perferably a meter/disconnect combination that eliminates wires from the meter to the disconnect, and uses mounted, insulated metal straps inside of one single box (not much chance of shorts). The idea of wires running from the meter, even a few feet, to the main panel is not something I like, unprotected wires/unfused wires are not a good thing.

Charles

 

[wilbilt]

Is the "lug block" at the upper right removable? If it could be removed and replaced with a 100A breaker, you would at least have a main disconnect.

You could then add a 100A breaker at the upper left to power your subpanel. You would still have a 100A behind a 100A, but at least you wouldn't have a 100A behind a 60A...

Another thing...is there no ground in that panel? I see two hots and a neutral.

Doesn't the NEC require the ground and neutral be bonded at the main panel (i.e., where the "main disconnect" is?)

In this case is the "main disconnect" your meter?

 

[wilbilt]

No, most places it wouldn't, but according to the NEC you can have up to six disconnects without a single controlling main. The NEC basically requires that you not have any more than six movements of the hand to shut everything off.

Personally, I like the idea of an outside disconnect, perferably a meter/disconnect combination that eliminates wires from the meter to the disconnect, and uses mounted, insulated metal straps inside of one single box (not much chance of shorts). The idea of wires running from the meter, even a few feet, to the main panel is not something I like, unprotected wires/unfused wires are not a good thing.

Charles

Exactly my point. How do you shut off the feeders? Pull the meter?

Do they enter the structure without any means of overcurrent protection? Scary.

 

[Charles (in GA)]

Is the "lug block" at the upper right removable? If it could be removed and replaced with a 100A breaker, you would at least have a main disconnect.

You could then add a 100A breaker at the upper left to power your subpanel. You would still have a 100A behind a 100A, but at least you wouldn't have a 100A behind a 60A...

Indeed it looks like that could be done, you would be using the 100 amp main breaker in a backfed condition, which is allowed. However, the main breaker, when backfed, must be (by NEC) secured with a retaining strap, screw, or clip so it is not readily removable. and the retiaining device must be approved for the panel.

Charles

 

[Charles (in GA)]

Exactly my point. How do you shut off the feeders? Pull the meter?

Do they enter the structure without any means of overcurrent protection? Scary.

Actually, any house that doesn't have an outside disconnect, is in this same situation. My house has a meter, no disconnect, and about 25 ft or more of Jacketed Service Entrance Cable running under the floor to the main panel in the laundry closet. There is a main breaker in this panel. If it were not so hugely difficult, time consuming and expensive (and leave me without power for so long) I'd rip out the whole thing and replace it from the meter on with a modern setup. My house was built in 1985 but without codes in the county, so the builder and owner did what they wanted.

Charles

 

[toxicz28]

Time to upgrade your service. I did mine for about $275 4 1/2 years ago with an electrician friend. If you have any of those, I would talk to them and your electric company about it. If you already have a 200 amp service, and want to upgrade your panel, all you need to do is pull the meter and the house is dead.

 

[wilbilt]

Charles, that does make sense. I guess I'm used to the locality (California). 90+% of residential panels are integrated with the meter socket.

There might be 6" of wire between the meter and the main breaker in most cases. In a case such as yours, it would most likely be required by the locality that there be a disconnect in close proximity to the meter.

Several years ago, my inlaws bought a new manufactured home to set on their property. The power drop went to a main panel on a pole, which also housed the meter. The pole was about 20' from the home, which had a panel mounted outside at the power connection point.

The inspectors were adamant that there be a breaker at the pole feeding the "feeder" to the home. The conductors from the pole to the home were trenched and in conduit. At the point the feeders came up next to the home (and directly below the main panel for the home), we were required to install a pedestal with a disconnect. This in turn fed the main breaker in the home panel.

So, in the course of 20 feet, there were three disconnects before the power entered the home. Running 25' of unprotected feeder cables around here would probably result in prosecution...

 

[TNToy]

Ideally, I'd like to upgrade to 100-amp service and re-wire this nightmare. I've done one panel before, about a decade ago. I don't doubt my ability to re-wire this mess, especially if I carefully label everything and have you guys to help and plenty of photos.

Let's assume I want to go that route for the moment.

If you were in my shoes, is this the route you'd take:
1. Find a box with similar (hopefully identical) dimensions.
2. Pull the meter to kill the power, verify with DMM.
3. Replace panel with new one which uses same style of breaker, and transfer everything over.

Now: (1)How do I figure out what my service capacity is? and (2)If I want to upgrade should it turn out that I have 100A service... what is required?

Is the meter only rated for a certain amount of current? What keeps people from installing a 200A panel and never telling the power company?

I should also clarify that the distance from the meter to the panel is about 18 inches. It's a very short run. If I had 25 feet of un-fused wire like Charles, that'd put a bug up my ****, too.

Will I need a permit/inspection/approval for this sort of thing? TN has among the most lax codes in the country (I used to live in Cook county, IL ... where conduit was mandated) compared to what I'm used to. So you never know around here.

 

[TNToy]

Now, let's also assume that I DON'T want to re-wire this nightmare...

Can I somehow figure out what the load capacity of the panel is? If it'll take it...

Can I slap a 200A breaker in where the main feed is now (assuming it's removable, checking tomorrow)...
Then toss a 100A breaker in place of the 60A unit in there now...
Upgrade the wires feeding the bottom half of the panel off the back of the main breaker...
And install a 100A breaker to power my garage sub-panel?

Oh, and does it look like I'd be able to make space for another double-pole breaker in there by using a pair of slim-line breakers on the 15A or 20A receptacle/lighting breakers at the bottom?

 

[TNToy]

Oh, and one more question - I think this is my 47th in about 8 minutes...

I have a line from a friend on a bunch of aluminum wire that might work to power the sub-panel. A 75-80 foot run should require #3 copper for both hots, right? If I remember correctly... this stuff was 2-2-2-4 romex.

Is number 2 large enough in aluminum, or do I need to step up to an even LARGER wire in AL? Does it require funky, expensive breakers - similar to the special AL-compatible switches and outlets found in older homes with AL 110V wire?

 

[mike944]

With that setup, i would suspect your service is something like 150, or probably 200A. You can tell by looking at the conductor size on the jacket of the incoming wires. Post the size, and i'm sure someone will tell you what the max capacity is. But just "eyeballing" them, they look pretty large, like 200A, or close.

You could also look at your meter. The capacity might be printed on the meter. Somewhere near the voltage rating.

I would NOT find a similarly physical sized panel. You need a larger one. that one is already "overstuffed" Personally, i hate double-breakers. I think most electricians would agree with me. They are a band-aid for an improperly sized panel. Besides, you need a special panel capabale of handling a double-breaker. Yes, you can make a double-breaker fit into a standard panel, but you're not supposed to. The panel is supposed to be rated for doubles.

If your reason for wanting a similar sized panel, is so you don't have to run new feeders, you could try a few alternates, which will allow you to get a proper-sized panel in there. Find a panel that feeds into the main breaker at the bottom (i've never seen one, but they probably exist) or, find one that feeds the main breaker at the upper left, so you can straighten out the feeders, and run them up the left side of the panel. This will gain you some extra distance. Or, you can find a panal that had a knockout for the feeders in the middle of one of the sides of the panel. You could mount the panel a little lower (you'll have to check code for minimum height)

No, you can't just slap a 200A main in there. The main is only for the lower half. That means, you'd be able to draw over 300A when you include the loads on all the upper breakers, fed off the lugs above the main. Your feeders defnitely aren't large enough to be 300A

Personally, i'd pull the meter, and replace the entire breaker box.

Here's an excellent book. One of his chapters covers service entrances. http://www.amazon.com/dp/1561581135/?tag=atomicindus08-20 It sounds like you understand the basics of wiring. That's good, because this is NOT a "for dummies" kind of book. You need a pretty good understanding of electricity beforehand, but it's an excellent how-to reference.

 

[wilbilt]

If the feed lugs are removable, I suppose you could put a 200A breaker in their place and use it as a main. It would be "backfed" as Charles mentioned. That's how all my panels are fed here.

The lower half of the panel is essentially a subpanel fed from the 60A breaker.

You should be able to make it work, and if you change anyhting it would probably require a permit. You might want to contact your local building department (...or not...)

Here, our meters have a seal installed by the power company. They are the only ones that are supposed to remove/install them. I changed my main breaker a few years back, and called the power company. They sent a tech right out, he pulled the meter and waited while I changed the breaker.

 

[PAToyota]

If you're going to go to the trouble of replacing it, I'd upgrade to 200amp. The box is already overloaded in my opinion and the workshop is only adding to the problem. Do it right, get the panel and meter upgraded to 200amp and then you won't have the future problems.

 

[TNToy]

Okay. I'll give the meter a look.

When I said "similar physical size" ... I meant external dimensions. Hopefully with at least two more breaker slots, yes. I'd just like to NOT have to tear a huge hole in the master-bedroom's closet while working on this and cover all of our clothes in sheetrock dust.


Why, oh why, did that HAVE to be my wife's side of the closet?

I'll take a look at the capacity stamped on the meter and go from there. I would really prefer NOT to have to install a new box. I've been killing breakers and looking, and they actually did an admirable job of branching-off seperate circuits for different rooms. Actually, a little too good. Two of those 15A breakers appear to each have 2 in-ceiling fixtures on them. Consolidating those into one breaker might by me the space I need. Again, provided I can consolidate things without overloading circuits.

I truly do not want to install a new panel. I haven't got any plans for the home that require additional breakers or circuits to be installed, so I'd prefer to avoid installing a whole new panel.

If possible, I'm going to try and swap a 100A back-fed breaker into the bottom half of the box, and slapping a breaker in for the sub-panel.

 

[TNToy]

Oh, and does anyone happen to know if I can run #2 Aluminum wire in place of #3 copper for my 75-foot 100A run?

 

[Junkman]

Don't forget to review your fire insurance coverage before you start making all these changes.

 

[TNToy]

Aluminum wire? Anybody? Bueller?

 

[Charles (in GA)]

Aluminum wire? Anybody? Bueller?

In your previous thread, Basic Electrical Plan... 2 Car Garage here is my post on this........

http://www.garagejournal.com/forum/showpost.php?p=79436&postcount=28

Charles

 

[PAToyota]

Actually, main panels in closets no longer meet code... Not sure if updating it they would make you move it?

 

[TNToy]

In your previous thread, Basic Electrical Plan... 2 Car Garage here is my post on this........

http://www.garagejournal.com/forum/showpost.php?p=79436&postcount=28

Charles

Thanks. Forgot about that.

PAT, the more I think about it, I think I'll probably try to up the 60A main to a 100A if it turns out the box and my service have the capacity. I just don't want to have to do a major renovation on the electrical system to install one breaker.

Also, yeah, I'm afraid it'd require a lengthy inspection process that leaves me without power to the entire home for more than a couple of hours. If we hadn't moved in yet, I'd definitely be wanting to upgrade. But it's the snowball-effect this type of project inevitably has that's got me running scared from a full-bore rewire...

 

[toxicz28]

Here, our meters have a seal installed by the power company. They are the only ones that are supposed to remove/install them. I changed my main breaker a few years back, and called the power company. They sent a tech right out, he pulled the meter and waited while I changed the breaker.

Funny you should mention that. When we did mine, we were allowed to cut the tag/seal, upgraded the meter pan and cable up to the roof of my house, and did the whole job inside. My friend who had the license from the power company called them to come out and re seal it, and called the electrical inspector. It took 3 years for the power co to put a new seal, and they only did that because they changed my meter. To this day, the electrical inspector has yet to show.

 

[bobbyd]

Just a thought. Why couldn't you look at it the other way around? Is there a way that the feeders from the meter could be intercepted and routed into a new small load center? In the new load center could be a 200A main (if feeders are capable) and two 100A disconnects (breakers), one for the existing house panel, one for the new garage panel. If I recall correctly, you mentioned that it was a very short run between the meter and panel. If so, could you place the new load center next to the meter, add a short set of feeders from the meter to the new panel and utilize the existing feeders and re-route them to the new panel in lieu of the meter?

Benefits: 1) positive disconnect for main, house and garage. 2) A small load center big enough for a 200A main and two 100A breakers should be relatively inexpensive, or at least less than replacing the house panel. 3) Don't have to screw around with suspect existing panel or risk overloading it. 4) All the work could be accomplished with the power on until inspection is made and would then just be a matter of landing new feeders to the meter lugs and existing feeders to the new load center.

 

[TNToy]

That... is a very interesting idea...

It's about as short as runs can possibly get. You see how the main feed from the meter comes through the back fo the box? Well, the meter is directly behind that.

So, I'd have to install the new box to the left or below the current one, and just feed the wires from the back of the current box, throuh the side of both boxes, into the new one. Then,. it'd come back into this box and hook into the main feed lugs at the top left.

 

[TNToy]

To find out the maximum capacity of my service, I look for a rating on the meter somewhere, right?

That is, the meter is what actually determines my maximum capacity? (100A, 200A, etc)

 

[Stuart in MN]

Along the lines of what BobbyD said, a common way to do the upgrade is to install the new panel adjacent to the old one, then gut out the old panel and use it as a junction box. That way, besides getting capacity for new circuits for the garage, you can put in all new breakers for all the existing circuits, run short leads from the new breakers into the old gutted panel, and splice them to the existing wires.

As far as identifying the size of the electrical service goes, you may or may not be able to tell by looking at the meter. They do have a current capacity written on the face someplace, but that just tells you the max current that particular meter can handle. For instance, a 200 amp meter could be used for a 100 amp service.

Another clue will be to look at the size of those big wires coming in to the box from the meter. If you're lucky you'll be able to see the wire size stamped on the insulation; a 100 amp service would be indicated if the wires are #3 or #4, a 150 amp service will be #1 or #1/0, and a 200 amp service will be 2/0 or 3/0 (these are wire sizes for copper, which is what it appears you have.) From the pictures, it looks like it may be 2/0 wire but that's just a guess.

You could also call your local electric utility, and they should be able to tell you what size the service is to your house.

 

[TNToy]

Thanks.

I don't know home wiring nearly as well as vehicles, but the wire gauge I can guesstimate pretty well based on oversized battery cables I've run in the past for winches, audio, etc.

I'd agree with your opinion... I'd say 2/0 is a pretty good guess. There's no size labeled on the insulation - I checked for that.

I'm just going to give the utility company a call and see if they can lemme know what my current service is.

 

[bobbyd]

Just so that everyone is aware, don't judge circuit current capacity by wire size alone. Let's say you do only have a 100A service but the electrician that installed the panel had some spare 2/0 cable laying around and used it. If you judged by the wire size alone, you could be screwed. Breakers are sized to protect the "smallest" or weakest link in the chain, which could be a device, meter, etc. and not necessarily the wire. It is not uncommon, nor against code, for wire to be oversized.

TNT has the right idea. A simple call to the utility company should provide a concrete answer.

 

[toxicz28]

To find out the maximum capacity of my service, I look for a rating on the meter somewhere, right?

When I upgraded mine from 100a to 200a, I changed the meter pan, and panel box (per the electric co). The meter remained the same untill they upgraded it to a wireless (for reading) meter.