Need 800 Amp total

[designer82]

This project requires an 800 Amp service (120-208V-3ph/4w) and I'm wondering the best way to do it.

I had initially specified an 800 Amp (Service Rated) Panelboard with 84 poles (need lots of circuits). Then I started looking at the mfg. (eaton/ sq.d) and see that these are only available up to 600 Amp from what I can see.

So now I'm thinking of splitting it this way:

mh1 — Postimages

postimg.cc

Could you let me know your thoughts?

Thanks!

 

[designer82]

Forgot to add unfused main disc. ahead of the wireway...

 

[masterinbama]

Forgot to add unfused main disc. ahead of the wireway...

What's your largest load?

 

[don_resqcapt19]

The code would not require the disconnect ahead of the wireway, unless the two panels are not "inside nearest the point of entrance of the service conductors". However, if that is the case you would need to use a fused disconnect or install some other type of OCPD immediately adjacent to the unfused disconnect to comply with 230.90

 

[designer82]

The code would not require the disconnect ahead of the wireway, unless the two panels are not "inside nearest the point of entrance of the service conductors". However, if that is the case you would need to use a fused disconnect or install some other type of OCPD immediately adjacent to the unfused disconnect to comply with 230.90

Ah right, this is in accordance with 230.71 right?

 

[designer82]

One thing I'm thinking is that this building is only one tenant and these are not two separate tenants.

I thought there's a section in the NEC that says the disconnect must cut power to all tenant loads simultaneously. (Although this could just be my imagination)

 

[don_resqcapt19]

One thing I'm thinking is that this building is only one tenant and these are not two separate tenants.

I thought there's a section in the NEC that says the disconnect must cut power to all tenant loads simultaneously. (Although this could just be my imagination)

No such rule in the NEC.

 

[augie47]

My thinking is in line with masterinbama's post #3. When you go to multiple panels you need to take a bit more core on distributing the load to each panel. Obviously a 100 amp load on an 800 amp panel has less effect on adding loads than the same 100 amp load on a 200 amp panel especially if motor loads are involved.

 

[electrofelon]

This project requires an 800 Amp service (120-208V-3ph/4w) and I'm wondering the best way to do it.

I had initially specified an 800 Amp (Service Rated) Panelboard with 84 poles (need lots of circuits). Then I started looking at the mfg. (eaton/ sq.d) and see that these are only available up to 600 Amp from what I can see.

So now I'm thinking of splitting it this way:

mh1 — Postimages

postimg.cc

Could you let me know your thoughts?

Thanks!

I'm sure you can get what you want in a single panelboard. For Siemens it would be a P4 for an 800A MB. Could be a P3 for 800 amp main lug. Can definitely get that with 84 spaces. That said something like 2 400's might be a little more user friendly. If you do use multiple panels, you could use 230.40 exception #2 off the CT so you wouldn't have to split them in a wire way.

 

[masterinbama]

My thinking is in line with masterinbama's post #3. When you go to multiple panels you need to take a bit more core on distributing the load to each panel. Obviously a 100 amp load on an 800 amp panel has less effect on adding loads than the same 100 amp load on a 200 amp panel especially if motor loads are involved.

My thinking too. 1 400 and 2 200's would most likely do the job and give you over 100 single pole spaces

 

[designer82]

Thank you for your replies, very appreciated.

I ended up going with this setup:

mh2 — Postimages

postimg.cc

The 600A panel ended up with 471 Amps demand & the 200 Amp panel ended up with 125 Amps demand.
The largest load is a 29.5 kVA elevator on the 600 Amp panel.
There will also likely be a 20 kW water heater going on the 600 Amp panel which will push it past its 80% rating but hopefully that isn't an issue with these Service rated panels.


Thanks again!