Junction box before service panels

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  #1  
Old 02-20-13, 08:54 AM
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Junction box before service panels

I am running power from my meter (400A) to my service panels in my basement. One panel is 200A, the other is 150A. I have run two sets of 4/0-4/0-2/0 aluminum service cable from the meter through a 4" PVC sleeve in the concrete foundation wall.

Unfortunately, where I was going to place the panels was too close to a sump pump pit. The cables are too short to reach an alternative spot to place the panels.

As an alternative, I was planning on installing a junction box (18"x18"x6") where the two sets of service cables enter the basement. I would place a pair of 3-pole splicing terminal blocks in the junction box. I would then run a pair of 3" conduit from the junction box to each service panel. The distance from the junction box to the service panels would be 4' and 5.5' respectively.

I know that ideally I would run new service cables. However, the ground is frozen solid here and won't be thawed out until April. It's a 200' run too.

Are there any obvious problems or code violations with this plan?

Thank you!

Ben
 
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Old 02-20-13, 09:55 AM
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Welcome to the forums, Ben!

Are there any obvious problems or code violations with this plan?
There shouldn't be, so long as you bond the box or trough, but it depends on your permitting authority. You should check with your inspector.

That said, I would use insulated multi-taps to make the splices. And don't you need three of them?
 
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Old 02-20-13, 10:17 AM
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Thanks for the welcome!

I was planning on using two sets of these for the conductors: COOPER BUSSMANN Splicer Terminal Block - Power Distribution Blocks - 4XK16|16303-3 - Grainger Industrial Supply

I'm assuming it would work, but I bet yours are probably less expensive?

The bonding comment does have me thinking now. I have 2 bare ground wires running through the 4" sleeve as well (each attached to multiple ground rods outside). These are long enough where they don't have to be spliced. Do I run 1 ground wire to each panel and then just bond the junction box to one of the panels?
 
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Old 02-20-13, 01:32 PM
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I was planning on using two sets of these for the conductors: COOPER BUSSMANN Splicer Terminal Block - Power Distribution Blocks - 4XK16|16303-3 - Grainger Industrial Supply

I'm assuming it would work, but I bet yours are probably less expensive?
IDK. It's been awhile since I had to buy any and the price is different for every wire size - range - and for the number of taps. They are a bit pricey, as I recall, but might be less than $90 each for the ones you need, though. Hmmmm... OK, just found the larger ones online for $39 each: PCT-4-4/0.

What I particularly like about the insulated multi-taps is that once you bring all of the conductors into a piece of trough - not a box - to allow you to space them out a bit, you just cut, strip, phase-tape, insert and clamp each conductor. When you've done the three wires for one phase, you just drop it and move to the next. You don't mount these to the enclosure and you don't need to fight the wire as much to get it to where you need it to be. Just make sure you have an Allen wrench that's big enough to fit the lugs.

The bonding comment does have me thinking now. I have 2 bare ground wires running through the 4" sleeve as well (each attached to multiple ground rods outside). These are long enough where they don't have to be spliced. Do I run 1 ground wire to each panel and then just bond the junction box to one of the panels?
You bond the trough by clamping one of the grounding electrode conductors into a lay-in lug bolted to the trough, then splice all of the GEC conductors together. Or you could mount a multi-tap lug block to the trough and terminate each GED conductor into that. Either way, you do it as the wires are coming through and going to the panels, just as you do with the current-carrying conductors.

That said, I've always had to strip an inch or so of insulation off the wire I wanted to use to make the bond. Uninsulated conductors aren't permitted in conduit anywhere that I've ever worked.
 
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Old 02-20-13, 06:57 PM
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I know that ideally I would run new service cables. However, the ground is frozen solid here and won't be thawed out until April. It's a 200' run too.
So, your meter is obviously quite a distance from the house and maybe on a pole? You don't mention having any overcurrent protection at the remote meter, but I am assuming there is either a circuit breaker or fusible switch at the meter location, correct? You mention cable, but I suspect you mean you have individual insulated conductors in conduit. If this is right, there should be 4 conductors to be spliced in a junction box and not just 3.

If there is no overcurrent protection at the remote meter, there may be an issue of the length of unprotected wiring inside your home. How long would that length be (now assuming no breaker at the meter location)?
 
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Old 02-20-13, 07:24 PM
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I've come to like Polaris bugs too. Everyone complains about the prices but the time they save makes up for it. Check them out.

Polaris Wire Connectors Shipped Fast



There has to be a disconnect at the meter. After the meter is the customers responsibility and it's not allowed to be that length without having a service disconnect.

Also.....I don't believe you (an end user/customer) can splice an unfused service cable.

It's a touchy subject.
 
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Old 02-20-13, 10:59 PM
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I'm gonna have to try some Polaris bugs on real wire one of these days - only used them on little stuff so far. I'm noticing that the ones that would be needed here are more expensive than the ones I'm used to using. They look more cumbersome too.
 
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Old 02-21-13, 01:58 AM
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Compared to regular bugs they aren't more cumbersome.
They can also be used the same as a split bug where the wires can be spliced end to end or ends parallel.
Sealing end caps and no tape required.
 
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Old 02-21-13, 11:51 AM
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Originally Posted by PJmax
They can also be used the same as a split bug where the wires can be spliced end to end or ends parallel.
Sealing end caps and no tape required.
That's all true with the Ideal insulated multi-taps too, for less money, as far as I can tell. That said, I'm still planning to look for some of the Polaris connectors the next time I need to split or extend some feeders, just to see the differences for myself. We'll see what the supply houses have. Different ones, around here, tend to carry materials from different manufacturers. I'm willing to bet I can't find both the Polaris and the Ideal splicers on the same counter.

Ben, the last time I spliced feeders, it was in a trough under a set of distribution panels. But we had run the power from the remote CT cabinet (meter) to a set of fused disconnects on the outside of the building. The feeders I was splicing came from the fused side of one of those disconnects.

That's not to say it can't be done. We have also spliced the unfused POCO feed to go to multiple meter bases and disconnects. That was also done outside, of course.

Here's what I would suggest: Mount a pair of 200A fused disconnects on the outside of the building. Mount them directly opposite your panel locations. You can fuse one of them at 150A.

Originally Posted by barefaceben
I have 2 bare ground wires running through the 4" sleeve as well (each attached to multiple ground rods outside).
Keep those outside and use them to make the service entrance bond at - in - the disconnects. Then bring the power and GEC through the wall into the back of each panel. Make up the panels as subpanels, with bonded grounds and isolated neutrals, since you have the MOCP already, in the disconnects. You won't need any J-box, trough or splices, either inside or outside. You also won't need a main breaker in either panel, unless you want one for convenience.

I would sketch this out and walk it by the AHJ, at least at the field inspector level, before investing the effort and expense to make it happen. But I think it would be acceptable.

Let us know what they say.
 
  #10  
Old 02-22-13, 09:30 AM
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The response from the inspector:

"Your solution is acceptable. Make sure your box you are planning on using is correct in size, preform the appropriate grounding. A reminder to keep the length as close as possible to the entrance."

There is no overcurrent protection at the meter. I initially thought the same as most of you. A disconnect with some form of overcurrent protection would be required. However, after talking to several local electricians (not new to the area either), they said that this was only required on modular/manufactured homes and not stick built. In my setup, I would ground the panels and not run a 4th conductor to each one (since this is the first disconnect).

Even if this is allowed in my area, it doesn't seem to be the norm around the country. It really doesn't seem to be that safe either I guess.

Nashkat1, I thought about doing what you describe (2 disconnects outside the house. However, the spot is terrible. The underground entrance to the utility room is right below my front door (and concrete patio). Relocating the entrance to another side of the house and running SER through the house doesn't seem too realistic either (lots of digging in frozen solid ground).

If I did have a disconnect with overcurrent protection next to the meter, I would be short a conductor for each set of cables.
 
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Old 02-22-13, 12:57 PM
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If I did have a disconnect with overcurrent protection next to the meter, I would be short a conductor for each set of cables.
How so? What conductor would you be missing?

The 2 hots and 1 neutral from the POCO feed the disconnect. The GEC/neutral bond is made there. 2 hots, 1 neutral and a ground go from there to the panel.
 
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Old 02-22-13, 01:46 PM
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If I installed the disconnect right next the meter (and made the ground-neutral bond there), then I would be missing 200' of ground wire to get from there to the panel inside the basement.

If I placed the disconnect right outside the house, then that wouldn't be an issue. However, as mentioned previously, the location of the entrance (right under the front porch) makes doing this very difficult.

Does that make sense?
 
  #13  
Old 02-22-13, 07:50 PM
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Yep. Got it now. That's why I always put the MOPD on or inside the structure. But it sounds like you've got it solved. Just remember that you'll be splicing all four of your feeds inside the box or trough, that 3 of those need to be insulated, and that the fourth one needs to have the box or trough bonded to it.

It's nice that your inspector agreed with your solution.
 
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