Main Panel Service Upgrade Mounting in Unfinished Garage

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  #1  
Old 07-19-13, 11:22 AM
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Main Panel Service Upgrade Mounting in Unfinished Garage

I am upgrading my service to 200 AMP and have a new panel already installed in my garage, which does not have drywall. The old panel is still there and the plan is to remove it once the new panel is approved and service connected.

The new panel is recessed in a stud pocket extending just enough that it would be flush with 1/2 drywall ( no plans to finish garage, but why not). The master plan is to have the meter box right on the other side of the wall and have a 2" conduit go up and through the roof creating a mast for the relocated service entrance.

I have been debating how to securely anchor that mast/conduit to the side of the house. I am now considering moving the main panel further in from the exterior wall so I can run a 2x4 behind the panel and use that to support the lowest strap for the condit slightly above the meter box. I guess I could also put the entire panel on plywood screwed over the wall's 2x4s, but I can't picture how the wires would run out from the top of the box and up the walls.

Any suggestions or red flags here? I have seen boxes secured to plywood in basements and that plywood ran all the way to the floor joists above and wire staples were used to secure the wires to the plywood

Also my old box has some circuits as aluminum wires and I was thinking of putting small boxes on an extended plywood board with the new service panel to hold the transition from aluminum to copper before entering the new box.

Thanks !
 
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  #2  
Old 07-19-13, 11:41 AM
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Your power company should have a design book that shows what they require for support for a mast. One near me requires all thread into solid wood bracing let into the studs. Others may be different. This design book may be on-line for viewing.

I would not add un-necessary junctions to any circuit. The breakers should already be listed for use with AL.
 
  #3  
Old 07-19-13, 12:35 PM
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What is the outside wall? That is, how is it constructed? How are you planning to secure the meter base?

When I (we) upgraded the service in an older house some years ago, the meter base was mounted to the block foundation and the mast was secured to the frieze board at the top of the first floor - at least 12' up from the top of the meter base. I don't recall any additional straps in between. The mast also ended there, under a pigeon walk. The strain relief for the triplex was secured to the frieze board and the framing behind it.

Do check with your POCO and your inspector. Local requirements rule.
 
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Old 07-19-13, 12:48 PM
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I would not add un-necessary junctions to any circuit. The breakers should already be listed for use with AL.
I agree with pc boss...... keep the splices out of the aluminum lines.
 
  #5  
Old 07-22-13, 10:10 AM
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Thanks for all the replies.

The construction is wood 2x4, 1/2 inch plywood and vinyl siding over a thin insuation board (white foam). I was planning on securing the meter box to the plywood with all weather screws. The mast would be secured to the wall with heavy straps that take a screw on each side. They might even have a small bolt/nut to grip the mast. The straps would be screwed that to 2x4s running horizontally between the wall studs with some heavy lag bolts.

Good point about the aluminum wires. Unless I have the wires fall short because the box is slightly further away from the front of the house, I will try to avoid a box and the purple wire nuts.

I guess my biggest concern is I have a lot going on in the stud cavity where the new panel is sitting. Most of the circuit wires will be running up that cavity. I also was hoping to beef up the area with some horizontal studs to anchor the mast to. I don't know if moving the panel out and placing it on plywood is a good idea.

If the final design has a guy wire, which it very well may have, I guess the total effect on the mast and box will (unless something fails ) be a downward force... and I am mostly concerned about the pull of the wires and keeping the mast from twisting and trying to break away from the meter box.

Maybe my focus should be making sure the box is anchored well to resist this.
 
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Old 07-22-13, 12:17 PM
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Anchoring the box securely still does not help with the weight of the overhead wiring or the wind load from movement.

Check out some of these parts. My power company will not allow a 2 hole strap or Kindorf strap to support the mast.

Mast Parts
 
  #7  
Old 07-22-13, 12:55 PM
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I am mostly concerned about the pull of the wires and keeping the mast from twisting and trying to break away from the meter box.
The overhead feeder wires are not supported by the mast.
Originally Posted by Nashkat1
The strain relief for the triplex [is] secured to the frieze board and the framing behind it.
I also was hoping to beef up the area with some horizontal studs to anchor the mast to.
I'm not convinced you need to secure the mast between the top of the meter base and the frieze board at the top of your wall. If you think you do, the blocking would work best if mounted with the wider face against the inside of the plywood sheathing, leaving you with plenty of room to run cables inside the stud cavity.

Note: A stud is, by definition, a vertical framing member. Framing members mounted horizontally may be plates, headers or blocking.
 
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Old 07-22-13, 12:57 PM
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If the two hole strap looks like what comes with the mast kit, that is similar to what I was sold years ago when I purchased parts from the local electrical supply co. The clamps are pretty heavy duty galvanized steel, but I never cared for the look of it. I would have preferred the "universal pipe support", but they didn't have those ( or maybe I wasn't clear). Seems like the two hole/two bolt would be stronger at resisting the pull of the wire on the mast.

Are the universal type what is recommended? I will try and take a picture of what I have and post it.

Thanks
 
  #9  
Old 07-22-13, 01:21 PM
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Nashkat1. Thanks for the lesson on studs vs blocking. Certainly helps to clear things up if I use the right terminology. Also mounting the blocking as you said makes perfect sense and does allow more clearance. Not sure if it would fit behind the box as is (for the lower clamp), but would probably be close.

I also looked up what a freize board is. Now I know that too.

Any idea what kinds of force a mast would experience holding a cable strung from a pole 80 feet away? I have a feeling I will need some support from a guy wire as I will try to get as much clearance as I can and try to get close to within a few feet of the garage peak (current location)
 
  #10  
Old 07-22-13, 01:23 PM
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The overhead feeder wires are not supported by the mast.
Depends on the utility. Of the three different utilities in my area I would say the majority of the residential service drops are supported by the mast. They DO require backstays on the mast to resist the pull of the drop as well as secure mounting of the mast.
 
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Old 07-22-13, 01:34 PM
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Please check with your power company for their design guide so no time or materials are wasted installing something they will not connect to. Depending on the overhead span you may even need to run 3" rigid pipe to support the triplex.
 
  #12  
Old 07-22-13, 01:36 PM
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If you're extending the mast above the roof and securing the service drop to the mast, then you will need backstays, or guy wires, as already discussed. The method I was talking about starts with having the weatherhead below the overhang of the roof.

If keeping the top of your mast below the roof is an option for you, you can ask your utility for their design guidelines. That's probably a good idea anyway, and you may be able to find it online - many utilities have posted their requirements.

ECHO, ECHO, Echo, echo...
 
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Old 07-22-13, 01:39 PM
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Here is a link to one power company design guide as an example. Start on page 92.

http://www.bge.com/customerservice/s...ll_Version.pdf
 
  #14  
Old 07-22-13, 02:49 PM
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Nice Document. Need to Get Details from POCO/Town

That specification document from Baltimore Gas and Electric really clears up the issue of mast size based on height above roof, length of supported cable and cable type, clamp types and position, conductor length at weatherhead, etc.

I will have a rep from the POCO coming for a site visit and I will ask all of these questions, but I think they will defer to the local townships inspection for some of that.

I was also surprised that, unless I read it wrong, that Baltimore does not allow the mast to enter to top of the meter box. I definitely need to clear that up for my setup. It makes sense, but I didn't think about it when I popped off the knockoff. woops....

I really appreciate all the help that the forum members provide. It really helps clear things up for me. Thanks again.
 
  #15  
Old 07-22-13, 03:45 PM
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I was also surprised that, unless I read it wrong, that Baltimore does not allow the mast to enter to top of the meter box.
You got it right. BG&E doesn't allow the meter socket to be entered through the top or back wall. That means a separate piece of pipe to go the panel, unless by "enter" they mean only the service feeders. Check with your people. I've done work in BG&E's service area, but we didn't use standard residential meter bases. PCboss probably has a lot more experience with them than I do.

I also noticed that BG&E does not require, nor expect, that the mast head will be above the roof. Again, check with your people.

I will have a rep from the POCO coming for a site visit and I will ask all of these questions, but I think they will defer to the local townships inspection for some of that.
The POCO sets the standards in almost all cases (I don't know of any exceptions). They often allow the electrical inspector to approve the installation, so they don't have to staff up just for that.
 
  #16  
Old 07-22-13, 04:01 PM
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Here are two more installation guides:

Dominion Power See p.31 and Section 700.

Northern Virginis Electric Cooperative You want section ID-OHS (Installation Drawing for Overhead Service). It starts on p. 73, according to the page counter in my pdf viewer.
 
  #17  
Old 07-22-13, 09:00 PM
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BGE does not allow entries into or out of the top or back of the socket. You can use the side or bottom knockouts.

They do allow a mast above a roof when additional height is needed. IIRC it is somewhere on the pages prior to 92.

In my experience, a mast extends above the roofline, a riser is below the roof and ends in a weatherhead. The triplex would be anchored to the building. With a mast the triplex is anchored to the mast itself.
 
  #18  
Old 08-28-13, 01:36 PM
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Guy wire details

I had a visit today from the POCO rep and he suggested that I install a guy wire for my mast that is 2" rigid conduit and will extend 30" above the roof. Can anyone point me in the direction of the materials and practice to use when installing this type of support.

I assume that the guy wire will anchor to the attachment clamp and should be directly opposite the service entrance wire to something substantial under the roof sheathing. 45 degree angle to roof? type and gauge of wire? type of fastener on the roof.

Thanks again in advance for all the expertise.
 
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Old 08-28-13, 02:05 PM
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What does the installation manual from your POCO show? It should be available online. If not, call their engineering department and ask.

In Hawaii they require 2 guy wires with a 60[SUP]o[/SUP] - 90[SUP]o[/SUP] angle between them. The guy wire clamp attaches above the strain relief clamp: Electric Service Installation Manual. See p. 12. I have no ides how that might apply where you are.
 

Last edited by Nashkat1; 08-28-13 at 07:31 PM.
  #20  
Old 08-28-13, 07:07 PM
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In Hawaii they require 2 guy wires with a 60o - 90o angle between them.
Just curious, how did you happen to pick a power company in Hawaii for an example?
 
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Old 08-28-13, 07:12 PM
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he suggested that I install a guy wire for my mast that is 2" rigid conduit and will extend 30" above the roof.
30" above a roof is a bit marginal when requiring guy wire support. Can you reduce the height to 24" above the roof and forget the guy wires? That would be my first choice. My second choice would be to increase the conduit size to 2 1/2" for 30" height above the roof if I could forget the guy wires. Anchoring guy wires to a roof deck is just an invitation for leaks.
 
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Old 08-28-13, 07:39 PM
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Just curious, how did you happen to pick a power company in Hawaii for an example?
It popped up early in a search, I liked the layout, and it clearly had no relationship to work in NJ. I liked that because the answer to this is to do what the POCO will accept.

Back on topic, I like both of your suggestions for avoiding the need for guy wires and, in particular, your point about the advisability of avoiding them.
 
  #23  
Old 08-29-13, 07:27 AM
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I'll echo what has been said before. The power company will have drawings online of exactly what's required. JCP&L for example:
https://www.firstenergycorp.com/cont...ricService.pdf

See page 42. It has all the details you need in terms of guy wires.

(I see the OP is in NJ, though there are at least 2 power companies serving NJ depending on specific location)
 
  #24  
Old 08-30-13, 08:13 AM
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Thanks for the posts and the JCPNL document. I did review that and see the details on the attachment for the service entrance cable. I will have that mounted to the mast, but didn't see any details on guy wires, like the # required and angle, type of wire, thickness, etc. I will scour the web and see what the local electrical supply shop can recommend.

I can't go less than 30" because I go through the roof just over 10' above grade. In order to clear a walkway I need to be at least 12',so I am cutting it close as it is. I would go even higher... although I don't like the look of the mast being too high. in that same JCPNL document, they will allow 30" unsupported height for a 2" rigid mast. above that requires a 3" mast.

When I talked to the engineer who visited my house, he said they would pull the wire until I get the clearance I need. It has quite a bit of sag right now. I am a lot worried that I should have the mast beefed up with additional (although not required) guy wires, so there is no issue with it failing when they are doing the install. He pretty much stated that the mast being able to support the wire is on me.

Currently the attachment point is at the peak of the garage about 4' higher than the side of the garage and it drapes over the driveway. I am attempting to move the wire off the driveway, but I may have to abandon this if I can't get the clearance I need.
 
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