200a Subpanel feeds

[Russ Stacey]

I have an 800 amp MDP. out of this 800 amp MDP, a 200 amp breaker feeds a 200 amp secondary main lug MDP, in this 200 amp SMDP I have TWO, 200 amp breakers feeding separate 200 amp sub panels.

This is a previous installation, and I have to make changes to the facility this is installed in.

Will this configuration create an issue with the inspector for the changes I need to make on my work in the existing 800 amp main MDP?

Thank you

[David Hays]

You might want to consult an electrical engineer and pull a permit.

[Russ Stacey]

Why would I need to consult an EE to ask about existing equipment?, this is an inspection question.

Since I have already stated that my issue was with this EXISTING equipment conflicting with my NEW inspection on MY changes to the service it should be obvious,.... I already pulled a permit.

That was nothing more than a "I have no clue what this person is asking, but I MUST say something",... comment.

Anyone with some real answers like to respond?

Thank you

[Jeffrey R. Pope]

Originally Posted by Russ Stacey

Will this configuration create an issue with the inspector for the changes I need to make on my work in the existing 800 amp main MDP?

There are really no "issues" with the 200 amp breakers on the load-side of the service disconnect. I'm not to sure of what your concern is.

Though they will never likely draw their maximum capacity, the 200 amp breakers still act as disconnects for the panels they serve.

[Robert Meier]

I think that he's questioning having one 200 amp OCPD protecting 2-200 amp panels:

...200 amp breaker feeds a 200 amp secondary main lug MDP, in this 200 amp SMDP I have TWO, 200 amp breakers feeding separate 200 amp sub panels

There is no problem if the calculated load is 200 amps or less.

[Russ Stacey]

Originally Posted by Robert Meier

I think that he's questioning having one 200 amp OCPD protecting 2-200 amp panels:

There is no problem if the calculated load is 200 amps or less.

That is correct! Now we are getting somewhere.

200amp X TWO panels, or 200 amps across both panels?

Thanks

[Jeffrey R. Wicklander]

The biggest problem you might encounter would be possible nuisance tripping if you have heavy loads. It all depends on what you are planning on running out of those two subpanels. If you plan on running a few RTU's, a lot of exhaust fans, a Liebert and a sh*tload of lighting, you might have something to worry about. If it's just normal everyday application loads, I wouldn't worry about it.

Where do you reside?

Jeff