Outdoor 400 amp disconnect.

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Ryancbell121

Ryancbell121

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Location
Pennsylvania
Occupation
Master Electrician
The wall where the 2 new services are going is almost too small. This means to save room I will have to Knockout a 4 inch hole in the top of the outdoor service disconnect for the feeders to the electric room inside. I was thinking of just using 4" pvc from the dc so its easier to back to back LB the wall. So my question is, what is the best method for using the top of outdoor equipment with conduit? Myers hub to pvc connector to pvc? Or, Myers hub to emt connector to emt? Or other?
 
Welcome to the forum.

A 4" LB is a big beast. Where will the meter be connected? And what's the inside layout?

Can you post a pic or two of the wall and a better description of your proposed idea?
 
Sometimes you can make a gutter or pull box work below the meter or above and then hit the top or bottom of the 2 panels. This would let you get a more specific location for the panel KOs. The other issue to keep in mind is the 6x distance for the conduit when sizing this.
 
LarryFine said:
Welcome to the forum.

A 4" LB is a big beast. Where will the meter be connected? And what's the inside layout?

Can you post a pic or two of the wall and a better description of your proposed idea?
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Thank you. Unfortunately, I'm unable to post a picture. (For some reason you need the http:// text?)

The meter will be located to the side of the CT Cabinet. The Disconnect will be located to the other side of the CT Cabinet. On the other side of the wall where all the service equipment is located are the restrooms. The ceiling is 9 feet high in the restrooms so that means its better if we run conduit above the ceiling. This makes me want to come straight out from the top of the outdoor service disconnect with 4-inch conduit. I have always heard and understood that it's not the best practice to knock out a hole in a 3r piece of equipment in the top section, because water will get in eventually. Is this true? What's the best method to use the top section of the 3r disconnect? Or am I even allowed to do this, because some 3r equipment's say it voids their weatherproofing.
 
Ryancbell121 said:
Thank you. Unfortunately, I'm unable to post a picture. (For some reason you need the http:// text?)

The meter will be located to the side of the CT Cabinet. The Disconnect will be located to the other side of the CT Cabinet. On the other side of the wall where all the service equipment is located are the restrooms. The ceiling is 9 feet high in the restrooms so that means its better if we run conduit above the ceiling. This makes me want to come straight out from the top of the outdoor service disconnect with 4-inch conduit. I have always heard and understood that it's not the best practice to knock out a hole in a 3r piece of equipment in the top section, because water will get in eventually. Is this true? What's the best method to use the top section of the 3r disconnect? Or am I even allowed to do this, because some 3r equipment's say it voids their weatherproofing.
Click to expand...
You have to look at the instructions as some 3R equipment has a prohibition on top entry, and others permit it using a specified entry method. If neither of those apply, the only thing that is code legal with a PVC raceway would be the sealing ring designed to be used with the male adapter.

It is a best practice to never enter the top of any enclosure in a wet location, but sometimes you don't have a choice.

I think I would look at a wireway run vertical next to the disconnect, connecting the wireway to the disconnect below any energized parts. Run that up to the desired elevation and come out of the wireway through the wall.

If you do run conduit note that it is not likely a standard LB will be suitable for the size and number of wires you will be installing.
 
don_resqcapt19 said:
You have to look at the instructions as some 3R equipment has a prohibition on top entry, and others permit it using a specified entry method. If neither of those apply, the only thing that is code legal with a PVC raceway would be the sealing ring designed to be used with the male adapter.

It is a best practice to never enter the top of any enclosure in a wet location, but sometimes you don't have a choice.

I think I would look at a wireway run vertical next to the disconnect, connecting the wireway to the disconnect below any energized parts. Run that up to the desired elevation and come out of the wireway through the wall.

If you do run conduit note that it is not likely a standard LB will be suitable for the size and number of wires you will be installing.
Click to expand...
I wish I could show you the picture of this wall. Its only 13'4" and it needs 2 serivces. Each with CT Cabinet at 36x36, meter with 12" min nipple, and 400 amp disconnect.

So now it seems that I need 2x2 Junction boxes on each side of the wall for the 4" conduit to enter the building and turn down the wall to the electric room. I thought the 4" pvc lb would work but thanks for correcting me.v
 
don_resqcapt19 said:
You have to look at the instructions as some 3R equipment has a prohibition on top entry, and others permit it using a specified entry method. If neither of those apply, the only thing that is code legal with a PVC raceway would be the sealing ring designed to be used with the male adapter.

It is a best practice to never enter the top of any enclosure in a wet location, but sometimes you don't have a choice.

I think I would look at a wireway run vertical next to the disconnect, connecting the wireway to the disconnect below any energized parts. Run that up to the desired elevation and come out of the wireway through the wall.

If you do run conduit note that it is not likely a standard LB will be suitable for the size and number of wires you will be installing.
Click to expand...
Also, why do they make 4" LBs if the distance between the entrance of the 2 raceways isn't 6x the diameter of the 4" (24 inches apart)?
 
Ryancbell121 said:
Thank you. Unfortunately, I'm unable to post a picture. (For some reason you need the http:// text?)
Click to expand...
You should be able to paste pics directly into the forum response window.

The meter will be located to the side of the CT Cabinet. The Disconnect will be located to the other side of the CT Cabinet.
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Can you place the CT cabinet below the meter and disconnect? You should then have room to use side knockouts and elbow(s) or LB(s).

I have always heard and understood that it's not the best practice to knock out a hole in a 3r piece of equipment in the top section, because water will get in eventually. Is this true? What's the best method to use the top section of the 3r disconnect? Or am I even allowed to do this, because some 3r equipment's say it voids their weatherproofing.
Click to expand...
3R does not mean water-tight or water-proof. It means any water intrusion has a way out.

What you want to try to avoid is any penetration that is not below energized internal parts.
 
Ryancbell121 said:
I wish I could show you the picture of this wall. Its only 13'4" and it needs 2 serivces. Each with CT Cabinet at 36x36, meter with 12" min nipple, and 400 amp disconnect.

So now it seems that I need 2x2 Junction boxes on each side of the wall for the 4" conduit to enter the building and turn down the wall to the electric room. I thought the 4" pvc lb would work but thanks for correcting me.v
Click to expand...
PM one of us an email and someone else can probably post it for you. That way we can all see it and come up with multiple solutions for you that we all can benefit from.
 
letgomywago said:
PM one of us an email and someone else can probably post it for you. That way we can all see it and come up with multiple solutions for you that we all can benefit from.
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Alright I got it posted. The red was my rough plan and you can see how tight everything is going to be. I need the two disconnects on the middle of the wall for the future tenant and the new store.

I can only mount the meter above the ct with power company approval.
 
letgomywago said:
Maybe also putting the CT and meter in the shorter wall will fly but from what I've seen they don't like it without more overhang on the roof. POCOs like gable ends for this.
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So the existing ct and meter socket are getting replaced so that means I can mount the new ones over left more. It would be best to have the meter above the CT cabinets with POCO approval. That will give me more room for a 3x3under the disconnect to pull wire up the side of the disconnect to another 2x2 j box to enter the building.
 
Do you have the required 110.26(A) work space between the proposed disconnect and the transformer? Depending on code cycle you would need that clearance to the transformer concrete pad.
 
don_resqcapt19 said:
Do you have the required 110.26(A) work space between the proposed disconnect and the transformer? Depending on code cycle you would need that clearance to the transformer concrete pad.
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Its 120/208 so it would only need 3 ft between exposed live parts on both sides of the working space. Condition 3 Table 110.26(A)(1)
 
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