Question about making new knockout on meter main.

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Old 01-05-11, 02:13 PM
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Question about making new knockout on meter main.

We have an existing 200 amp residential meter main with distribution.(outdoors) We intent to install a 100amp commercial meter main w/ Test bypass alongside the existing residential panel.( for commercial metered usage on a separate structure.)
The only way to feed out of the commercial panel is out the bottom of the utility side. and the only pre-cut K.O's are on the top of the commercial panel top, for hubs. There is not enough clearance on the top of the 'future' comm. panel to route a gutter or EMT to the top..via the factory hub holes.
THE QUESTION: Can a new K.O. be cut on the 'side' at the top of the panel for the feeders, without violating NEC code?,

so basically gutter/or EMT from the bottom of the 200amp residential panel..over.. then up to the 'new' cut KO..
Also, (separate question), if a new K.O. is allowed, would a Meyers hub be a better choice for making the seal to the commercial panel. ( not with EMT, due to treading differences.)or would just running EMT with watertight compression coupling be fine?
thanks, I could not find anything in the NEC covering this.

more info: the comercial panel is: cooper b-line 214MTB
The 200amp main panel is right below a deck, with the service mast going through the deck and up, and there is not enough room below the joists to get any sort of gutter above either panel.
 
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Old 01-05-11, 02:42 PM
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Cutting a new hole in the panel is okay with the NEC as long as you have sufficient bending room for the conductors once they enter the panel. It's possible the factory KOs were located in one place for that reason.

Also, some power companies only allow entrance/exit conductors on certain sides of the meter box, so that could be an issue based on power company policy in your area.
 
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Old 01-05-11, 06:10 PM
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so basically gutter/or EMT from the bottom of the 200amp residential panel..over.. then up to the 'new' cut KO..
It sounds like you are trying to feed unmetered power to the line side of the commercial meter socket so both services will be separately metered. To do so from the residential combo, you seem to be planning on bringing unmetered power from the Line Lugs in the residential socket, down through the customer/main breaker section and then routing to that new knockout you are planning to cut in the commercial socket. I see 2 problems (if this is what you are trying to do). #1. Typically, unmetered power cannot run through the customer section of the gear. #2. Typically, the Line Lugs in the 200 amp residential socket are intended and will only accept one conductor.

If I am wrong with my assumptions, please provide a little more information on exactly what you are trying to do and someone on the board will try to help you. If my assumption is correct, it will not work.
 
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Old 01-06-11, 12:11 PM
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yes and no.

The feed to the metered commercial panel is through the utility side of the 200 amp residential main panel,not the distribution side. there are already an additional set of lugs within the utility side. The feeders down through the bottom of main panel through ridged nipple into Meyers hub / into 36" gutter/ over to 2nd 24" gutter vertically placed adjacent the commercial panel, up and onto every top of side of meter/utility side of panel. via Meyers hubs There is antiquate room inside the panel to adhere to 312.6 the Inspector ( AHJ )did already sign off the first installation of the commercial panel, but PG&E requested a test bypass panel be put in.
more info: They only plan running a 30amp welder and a couple of lights, and general plugs. They may get a radial band saw but this would not be running during the use of the welder.as this is a one man show. in any case they are changing out the panel and ran into this 'cramped' situation" and needed some clarification on what was allowed.
 
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Old 01-06-11, 12:44 PM
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Since it's a smaller welding unit, you could consider dropping your feeder to 50A. That would make hooking up a flexible/temporary power distribution panel quite a bit cheaper than the 100A option in your other thread.
 
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Old 01-06-11, 01:05 PM
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Are you saying unfused conductors would be sharing the same panel space as fused conductors?
 
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Old 01-06-11, 04:49 PM
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unfused?

tThe commercial feeders leave lugs in the service side of the main residential panel.. just below the residential feeds,( before their meter).. they are both lugged on the same bar before any meter .. then the commercial feeders travel 3 ft to a 100AMp main breaker then trenched to another fused panel...

and so on..

thanks for the temp cord thought.. wondering if/how long I can get away with a temp distribution box to run the shop tools/welder??
all your time and help is appreciated.
 
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Old 01-06-11, 06:39 PM
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the Inspector ( AHJ )did already sign off the first installation of the commercial panel, but PG&E requested a test bypass panel be put in.
It sounds like you are almost there. Pardon the questions, but this seems to be a very unusual setup.
 
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Old 01-06-11, 10:59 PM
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unusual eh..maybe..

well pre-existing 200 amp residential panel.. so a later addition of a commercial panel for the new owners meant either.. paying PG&E to do a completely new .EXPENSIVE. drop from the pole/transformer, ( not free anymore!..they charge for everything but the wire.. including the salaries of the 3 estimating technicians that came out.. HA!)
or coming off of the preexisting panel. to a separate meter main. no PG&E charge there..

PG&E made it sound like it would be thousands and thousands to do a new drop and basically suggested that this would be the free/best way to reach the home owner's goal.
They sent 3 of their estimators out, this is when they said they needed to see a TB panel installed which brought about this question(s) of making a new KO on the side of the commercial meter main. one of the PG&E guys said he would like to see a bland new second service mast go up..( but the other guys said they did not have to do that..)
If money grew on trees.... I'm sure the clients would have just paid 2K or so.. for a new panel /mast /grounding system and paid PG&E whatever they intended to dream up as far as customer charges.. but this is an unincorporated area and they tend to jack the prices when not inside a city... from what Iv'e been told.

It is not too unusual to have a separate commercial meter on a large property where a business is running or going to start up.. especially when you see what they are calling the residential baseline!..it's a joke here: 3 florescent lights,one frig.. one computer.. anything over that and you're 200% over baseline!.. run a couple of space heaters and your 3-400% over baseline at .47 a Kwh..versus .22 constant on a commercial plan...As they charge residences more and more for using electricity I think more and more people are going to try to get Legit business up and running so they are not getting shaken upside down for more money.
ok ..a bit off topic there..
thanks for everyone's advice.
 
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Old 01-07-11, 07:32 PM
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All along through this thread I was thinking I'd like to see a 2nd mast too, alongside the first mast and connected to the same service drop. Even the way you are doing it there is the possibility PG&E will want to increase the size of the service drop because of increased load.
 
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