Distribution Enclosure Height Restrictions

[Simpuller]

I want to mount a splice enclosure (Distribution Panel) as shown in the image.
As I understand it as long as there are no manual operators in a panel then there's no height restriction.
Feel free to tell me what I shoud be calling this distribtion panel without operators.
The enclosure is 20in W x 38in H x 5.75in D.

Thanks for looking. Any help is appreciated.


https://drive.google.com/file/d/1-Drsg2e4xkSIz3oKbKjZTc933HTEV6en/view?usp=drive_link

 

[Elect117]

Access to the image requires permission.

The terminology used might be a little different than what I am used to. Splices are to be made in boxes, like gutters / wireways.

You are not supposed to make splices in a distribution panel where breakers are located. You can, if you follow the rules of 404.3(B) which points to 312.8.

There is a height requirement for any enclosure with any disconnect. See 404.8.

There is no height requirement for gutters, pull boxes, wireways, etc. I would note, however, if a feeder tap is made, then you will need to consider which tap rule and the distance required to install your OCPD to meet it.

 

[Simpuller]

Thanks. I just updated permissions on the image. The splice enclosure won't have any operators.
The wire gauge coming into the splice enclosure is 3/0 and both feeders are also 3/0.
The first sub is 4 feet away from the splice enclosure. The second will be 40 ft away.

 

[Elect117]

You should use 4/0 Cu for 225A main / subs. 3/0 is only good to 200A. Or install a 200A main. It is a violation of 240.4 (round up rule)

All feeders will require 4/0 or a tap rule.

 

[Simpuller]

90 degree Use-2 is 225 at 3/0. Unless my eyes decieve me.

 

[Elect117]

90 degree Use-2 is 225 at 3/0. Unless my eyes decieve me.

They do. See 110.14(C) and UL AALZ

They do not test or approve the use of 90°C ampacities where they are landed in panelboard, switchgear, bussing, breakers, fused disconnects, etc. The only approved use of that ampacity is in certain splices or mechanical lugs where not located in an enclosure. The rating is typically only used for the purposes of derating. Otherwise, you should use the 60°C for under 100A and 75°C for over 100A.

There are specific equipment (majority) that is rated 75°C at less than 100A but unless you specify it on the plan set and the contractor is purchasing the equipment, you should not use it. It is better off to go with the 60°C so the contractor can buy any equipment and it will still be compliant.

 

[Simpuller]

Many thanks. This is my home and shop and I am tackling a complete rewire on my own.
I really appreciate the input.
I have 400A available on the pole and to the mast.
I've been on the fence about going up to 400A because I don't need it now.
I know it looks goofy to have my Main disconnect outside be 225A and both my subs be 225A.
On the fence about increasing the main just for cost reasons since I don't forsee needing more than 225A.

 

[Elect117]

I would suggest talking this out with a a certified electrician.

Costs and lead times might help you narrow down the choice. You might be able to get a 400A rated disconnect and 225A breaker installed in it to reduce the cost impact of the initial install. That way if you ever need to you can upsize the subpanel runs later.

I would however suggest putting each feeder on their own breaker outside. So that one feeds the shop and the other feeds the home. For example, lets say you need to upgrade the shop but not your home, then you can isolate and upgrade that circuit without needing to rewire everything.

 

[Simpuller]

I certainly want to talk this out with a certified electrician.
In the old days when my father was building our house he made friends with the suppliers and they put him on the right track.
My local supplier got hot under the collar when I said i was using NM in a commercial red iron building.
Wasn't till the end of the converstation that he learned I was drywalling everything in at 1 hour rating.
I grew up with exposed emt everywhere in the house because it was an artist's loft.
I am determined not to have exposed emt.

There's nothing too complicated about this, but there are some strategy items I'm working through.
You've already corrected one error my supplier made on the 3/0.

I generally don't pull the trigger until vetted.
Thanks for your input.