Main/sub panel - service drop question

[bochnak]

I currently have a 100amp service panel for my home. One 20amp breaker is for the detached garage.

The utility company was over the other day taking some slack out of my drop from the pole to my roof. The technician said my drop can supply a 200amp service. Is this determined by the gage and length of the drop?

So my question is:

Can I place a 100amp sub panel in my garage w/o replacing the main panel in the home? What would be the best way to handle this? Would pics help? I plan on trenching gas and "more" electricity to the garage at some point. I doubt I can re-pull new wires and another circuit in the current run. And besides, it's never enough is it?

Thanks,
Matt

 

[nova65ss]

You can only go in the garage as high as the breaker that you are feeding it with. If you have a 20 amp breaker in the house you can only run 20 amps in the garage. Make sense?

 

[PAToyota]

Actually, you can bypass the panel in the house. I have a C320 (commercial 320, or 400amp) meter base that feeds a 200amp panel for the house and a separate 200amp panel at the detached garage. I did need to install a disconnect at the house for the garage service per the utility company's requirements. But you should be able to do the same with a 200amp meter base feeding two 100amp panels.

 

[bochnak]

You can only go in the garage as high as the breaker that you are feeding it with. If you have a 20 amp breaker in the house you can only run 20 amps in the garage. Make sense?

It makes sense. So, I would need a 100amp breaker in the main panel for a 100a sub panel in the garage that would also have a breaker? That run would then have 2 breakers, one in the home and garage? That would be annoying if the breaker in the main panel tripped instead of the sub panel. I thought that you can tap in and just make the run, but that run would be unprotected.

I am a novice when it comes this topic, and would have a electrician handle the work. I am just doing a bit of homework on how $$$ this can run.

 

[bochnak]

Actually, you can bypass the panel in the house. I have a C320 (commercial 320, or 400amp) meter base that feeds a 200amp panel for the house and a separate 200amp panel at the detached garage. I did need to install a disconnect at the house for the garage service per the utility company's requirements. But you should be able to do the same with a 200amp meter base feeding two 100amp panels.

We were typing at the same time, LOL. You descibed exactly what I had in mind. If I can bypass the main panel and put a 100amp sub in the garage, that would make it less expensive and easier.

Would the connection be made in my main panel for the sub? Or outside near the meter?

Thanks,
Matt

 

[markb1]

Pics would be helpful.
You need a meter sized for 200a and service entrance wire rated for 200a.
(the wire frome meter up to weather head)

Usualy the easiest way is to do a service change with 200a. rated Panel, meter, riser, then 100a breaker to feeder wire to shop then 100a panel with breaker.

 

[JMURiz]

I had something similar with my house, 150amp fuse panel in the house but 200amp wiring from the line to the meter. So I decided it was time to upgrade my house box to a 200 amp breaker box and run a 100amp sub panel off of that to the garage. All you need is the right size wire from the meter to the box, a new main box, a new sub box (might be able to reuse your old 100 amp house box!), and wires to hook up between them.

 

[bochnak]

Pics would be helpful.
You need a meter sized for 200a and service entrance wire rated for 200a.
(the wire frome meter up to weather head)

Usualy the easiest way is to do a service change with 200a. rated Panel, meter, riser, then 100a breaker to feeder wire to shop then 100a panel with breaker.

I’ll post some pics tonight of the following:

1. Main panel. (Should I open it up?)
2. Outside meter.
3. Service coming into pipe on roof.

Anything else that would help?

Thanks,
Matt

 

[PAToyota]

Would the connection be made in my main panel for the sub? Or outside near the meter?

Let me try to describe my setup a bit better. The drop comes in to the meter base and through the meter. After the meter, it splits. One feed exits the meter base and goes in through the wall to the 200amp panel in the house. The second feed exits the meter base and runs to a disconnect panel - just a switch, not with a breaker or fuse. From the disconnect it goes back to the shop where it enters the 200amp panel there. So the two panels are totally separate and there is only one main breaker for each.

The side benefit is that I can switch off the disconnect at the house and have absolutely no power going to the panel in the shop.

 

[kbs2244]

I like your set up PAT.
It is just one step short of having two seprate drops. The only thing they are sharing is the meter.
Did they want the disconnect outside where emergency guys can see it?
I worked with a fireman once who said the first thing they did when pulling up to a fire was to find the elect meter and pull it out of the box be sure everything was turned off.

 

[PAToyota]

Around here, a residence is only allowed one drop so I had to do it this way. With the large McMansions, there is actually a lot of this going on. Rather than one huge panel, they bring the service in through the C320 meter and then go to two panels at opposite ends of the house...

They allowed me to put the disconnect inside the basement, but I have heard that some places may interpret the regulations to mean that the disconnect has to be outside.

By the way, pulling the meter does not disconnect power... It continues to flow through without it...

 

[bochnak]

Let me try to describe my setup a bit better. The drop comes in to the meter base and through the meter. After the meter, it splits. One feed exits the meter base and goes in through the wall to the 200amp panel in the house. The second feed exits the meter base and runs to a disconnect panel - just a switch, not with a breaker or fuse. From the disconnect it goes back to the shop where it enters the 200amp panel there. So the two panels are totally separate and there is only one main breaker for each.

The side benefit is that I can switch off the disconnect at the house and have absolutely no power going to the panel in the shop.

Pat,

I understood what you meant. I wonder if I would be allowed to do this. Let me post some pics and that may determine which route to take.

 

[PAToyota]

I don't see why you would not be able to do it. You'd just be using a standard 200amp meter base and two 100amp panels. Although, I'd really consider checking into putting in a 200amp panel if you are putting a new one in. You can always supply more power to it later on.

 

[bochnak]

The drop and meter....

 

[bochnak]

The run....

 

[bochnak]

The panel.

1. The main reads 100.
2. The 4 below it read 20.
3. The rest are 15.

Some of the pics are small and poor quality. Let me know if you would like them reposted.

As you can see, my home panel is almost full. One of the (double pole???) 20's right below the main is no longer used. That circuit powered a laundry room upstairs that is no longer there (note the dryer vent hole in the brick).

What's a guy to do?

Also, my home is a 1000 sq ft. ranch with a full basement. Most homes in the area are the same, except many have added a second story. I might as well upgrade the main panel for future upgrades, like an addition, whether I or the next owner decides that route. It could be a selling point???

-Matt

 

[PAToyota]

What's a guy to do?

Ummm... Thought I explained that...

 

[Charles (in GA)]

Judging from the look of things in the pic, you will need a new.......

1) Mast/weatherhead, the old one won't be large enough for the new heavier Service Entrance cables from the weatherhead.

2) Meter socket, judging from the looks of yours, it probably is a 125 amp rated can.

3) New cable from the meter socket to the main panel board.

4)New 200 amp rated panel.

Many localities require the service disconnects to be located outside (for fire fighting purposes).

You could put in all of the above mentioned items and then run a 100 amp subfeed to your new garage panel.

Or you could us a meter can/service disconnect/breaker panel combo (GE makes one) that accomodates about 4 breakers. The idea is that you don't have to run wires outside to A/C units and such, just put the breaker in the panel outside. These are also good for running well pumps, or for subfeeds to outbuildings or garages, etc. Then you carry 4 wires inside to your new breaker panelboard, which is now, technically, a subpanel itself, as the disconnect outside is the main panel.

Mutiple service disconnects on one service drop (up to six are permitted by NEC) must be grouped together (NEC 230.71 and 230.72A) and as such cannot be separated, one inside and one outside. (both inside if allowed locally, or both outside, always together).

Charles

 

[markb1]

Your panel appears to be an old "Federal" brand "push-matic" type breakers.

A good reason to upgrade.

 

[bochnak]

Ummm... Thought I explained that...

Yes, you did, Pat. I appreciate it.

 

[bochnak]

So how much can I expect this to run me? New 200a main and 100a sub? Ballpark figure, I know there are many things to consider. This is obviously a job for a pro. I have a buddy who can probably do it on the side.

 

[bigdav160]

So how much can I expect this to run me? New 200a main and 100a sub? Ballpark figure, I know there are many things to consider. This is obviously a job for a pro. I have a buddy who can probably do it on the side.

I'd say at least a couple grand. From your pictures I cannot tell what gauge the incoming service feed is. I don't think it is over sized. Like Charles said (a couple post above) it is very likely you'll need more than a couple panels.

BTW, if I'm reading Pats post correctly, in my area they are very loose with building standards but residential double lugging at the meter is a big no no.

 

[bochnak]

I'd say at least a couple grand. From your pictures I cannot tell what gauge the incoming service feed is. I don't think it is over sized. Like Charles said (a couple post above) it is very likely you'll need more than a couple panels.

BTW, if I'm reading Pats post correctly, in my area they are very loose with building standards but residential double lugging at the meter is a big no no.

I live in the burbs of Chicago (Cook county) which is stricter than surrounding counties. For example, I have conduit while some counties run romex.

 

[cj7jeep81]

i did basically the same as pat. got a 400amp meter installed, that splits to two seperate 200amp disconnects. one then goes in the house to feed the 200 amp panel in there, the other is setting empty waiting for the shop to be built.

depending on what all you want done, shouldn't be more than $1500 or so (I would think). To install a 400amp meter base, 2 200amp disconnects, and wire the one 200amp to the house 200 amp panel was around $1400.

If all you need is a new 200 amp meter base with the 2 100 amp disconnects, I would think it would be cheaper (you'd still have to buy the 100amp panel for the shop, and run teh wire).

 

[Charles (in GA)]

BTW, if I'm reading Pats post correctly, in my area they are very loose with building standards but residential double lugging at the meter is a big no no.

So very true. Most 320 and 400 amp meter sockets have dual lugs for this purpose. Most 200 amp meter sockets DO NOT.

This is why I suggested a combo meter socket/disconnect/panel which will give you a 200 A disconnect and a place to put a 100 amp breaker to supply the garage sub panel. Less than $110 at Lowes and Home Depot. For a new 200 amp panel in the house, you cannot go wrong with a full size GE or Siemens "contractor pack" which includes most of the breakers you will need and a full size panel. Biggest problem I find is that when upgrading panels, the wires never seem to reach, and you end up replacing the romex from the panel back to the first box or junction on many circuits. A very time consuming task. In addition, you will have to run new service entrance from the meter socket to the new breaker panelboard.

Here is the one I mentioned, cheaper here than anywhere on line I found it.

http://www.lowes.com/lowes/lkn?action=productDetail&productId=149739-76863-TSM420CSCU&lpage=none

Here are a couple of other similar products.

http://www.milbankmfg.com/Products/MeterMainBreaker/index.asp

http://www.geindustrial.com/cwc/Dispatcher?REQUEST=PRODUCTS&id=lc-msfp

The beauty of these is that you don't have to do any heavy wiring from a meter socket to a disconnect. All other setups, you take a meter socket, and connect it to a disconnect with a ******, offset or something similar and fight with huge stiff wires in a too small of a space, then you mount it on your house and it looks like ****. This is one box, looks professional.

I just used a 150 amp version of this (same price, same unit except for the main breaker) and mounted it on a pole next to one of our community wells. The old installation was rusted, corroded and generally in poor condition, and was ripped off the post by someone mowing who snagged one of the conduits on the bottom. I couldn't buy all the individual parts (meter socket, small breaker panel, ******, 100 amp breaker to backfeed for a main, and other small parts) for what this cost, and no assembly required! I'll be installing another one of these this fall on another well. That panel is plain dangerous, with most of the knockouts broken out, and no covers or fillers, and the wasps and dirt daubers have made a mess of it. Rusted, corroded, weathered, it will get replaced.

In the pic, the main breaker is obscured by the lid. You can however, make out the knockouts for the additional breakers.

By all means, check with your power company, to insure that they will accept and provide power to whatever you install.

Charles

 

[PAToyota]

BTW, if I'm reading Pats post correctly, in my area they are very loose with building standards but residential double lugging at the meter is a big no no.

Thanks for catching that. The C320 (as I installed) has double lugs, but if you only had a 200amp meter base you could have a problem...

Sorry about that.

 

[markb1]

http://www.geindustrial.com/cwc/Dispatcher?REQUEST=PRODUCTS&id=lc-msfp

This panel has feed through lugs.

In the pic. you can see lugs at the bottom of the bus bars ( the metal part that the breakers mount to.)

You could attach 4/0 Al. wire (200a.) to these lugs and run to your main sub panel in the house.

That would give you a 200a. panel for your home and still do as Charles stated above for your 100a. shop panel.

 

[Charles (in GA)]

I'll add this brochure to the "reading list"

http://www.geindustrial.com/publibrary/checkout/38652.30055.29657.33096/PDF/DET-185.pdf

Charles

 

[bochnak]

Thanks for all the info., guys.

I actually ran into my buddy who is an electrician last night at street fest in our suburb. I told him to come over for some beer and pizza to discuss the project. I will show him the products mentioned above.


This project may not happen this year, our first child is due Nov. 1st. So, even if I had the work done, I would not have much time to tinker in the garage.