400 amp feed thru panel from panel A to panel A1 needs a Main CB?

[stuartdmc]

The Plan checker has corrected my plans and has stated that I need to provide a main circuit breaker for panel A1,(the secondary panel) per ?240.21, 408.36.

I have a 400 amp service with a 400 amp main breaker it's feeding panel "A", a 400 amp M.L.O. feed thru panel, then it comes off the feed thru double lugs with 400amp wire to panel A1 which is only 5ft away the Plan checker says that per 2410.210(b) it requires me to install a main in panel A1. is this Correct? I am not changing the size of wire anywhere. How should I comment back to him?

Thanks for your suggestions.

 

[infinity]

IMO the plan checker is incorrect since the main in panel #1 is protecting panel #2. Here's an similar installation I did last year with both panels being 400 amps.

 

[iwire]

This is not a tap as you are using conductors with an ampacity greater than 400 amps.

Have the plan checker take a look at the definition of tap conductor.

From 240.2

Tap Conductors. As used in this article, a tap conductor is
defined as a conductor, other than a service conductor, that
has overcurrent protection ahead of its point of supply that
exceeds the value permitted for similar conductors that are
protected as described elsewhere in 240.4.

So nothing in 240.21 applies .... assuming you do in fact have conductors rated for 400 amps



As far as 408.36 that is covered by a 400 amp breaker in any location.

408.36 Overcurrent Protection. In addition to the requirement
of 408.30, a panelboard shall be protected by an
overcurrent protective device having a rating not greater
than that of the panelboard. This overcurrent protective device
shall be located within or at any point on the supply
side of the panelboard.

 

[iwire]

IMO the plan checker is incorrect since the main in panel #1 is protecting panel #2. Here's an similar installation I did last year with both panels being 400 amps.

You do such awful work.

 

[stuartdmc]

Service Conductors in not less then 2" of Concrete?

Service Conductors in not less then 2" of Concrete?

sorry wrong post.
Thanks for your comments

 

[stuartdmc]

You do such awful work.

Thank is pretty work!
Thanks.

 

[Dennis Alwon]

Looks real good. I also agree that no main is needed. Those circuits are protected by the main in Panel "A". It is a sub panel

 

[augie47]

Looks real good. I also agree that no main is needed. Those circuits are protected by the main in Panel "A". It is a sub panel

I see it called a sub-panel and also just a "two section panel" which brings to mind an interesting question. If it's a service panel and the plans call the service as "two section service panel" do you bond the neutral in the 2nd section ?

 

[iwire]

If it's a service panel and the plans call the service a "two section service panel" do you bond the neutral in the 2nd section ?

LOL, I think Roger will enjoy that one.

250.24 Grounding Service-Supplied Alternating-Current
Systems.

(B) Main Bonding Jumper. For a grounded system, an unspliced
main bonding jumper shall be used to connect the
equipment grounding conductor(s) and the service-disconnect
enclosure to the grounded conductor within the enclosure for
each service disconnect in accordance with 250.28.

Luckily there would only be one service disconnecting means.

 

[Dennis Alwon]

I see it called a sub-panel and also just a "two section panel" which brings to mind an interesting question. If it's a service panel and the plans call the service as "two section service panel" do you bond the neutral in the 2nd section ?

I am saying that the panel on the right is a sub from the main panel. The main panel is just a main panel with feed thru lugs. IMO, it does not matter what the plans call it. If the panel is after a main then I do not bond the neutral to the can. I don't quite get what you are saying a a two section panel.

 

[infinity]

You do such awful work.

Thanks, fortunately I work for a company who expects nothing less and customers who are paying a premium for quality. :thumbsup:

 

[iwire]

It is common for us to install 2 or even 3 sections panels with all sections being 'sub panels'

So we might have 'Panel LP section 1, 'Panel LP section 2' and perhaps 'Panel LP section 3'

Section one has circuits 1-42, section 2 circuits 43-84 and section 3 would have circuits 85-126.

This comes in handy when supplying office furniture, circuit heavy but lightly loaded.

 

[stuartdmc]

IMO the plan checker is incorrect since the main in panel #1 is protecting panel #2. Here's an similar installation I did last year with both panels being 400 amps.

Wait a minuet,
There is a main breaker in the panel on the left, then you are feeding the panel on the right through lugs, Okay,

My plans are calling for a Main 400 amp breaker only at the main service , then the first panel is a feed thru panel "A" is without a Main just double M.L.O. then its jumping over to the panel on the right "A1" also with no main.
This is correct RIGHT?
Are we still talking about the same thing here?

 

[Dennis Alwon]

Wait a minuet,
There is a main breaker in the panel on the left, then you are feeding the panel on the right through lugs, Okay,

Are these lugs protected thru the main breaker or are they on the line side of the breaker?

 

[Dennis Alwon]

Okay if there is a main 400 amp panel with a main service disconnect then you do not need to encase the conduit as these are not service conductors. My question remains -- are these conductors protected by a breaker or some overcurrent protection device. If so then there should be no problem.

Sounds like your situation is okay

 

[stuartdmc]

Okay if there is a main 400 amp panel with a main service disconnect then you do not need to encase the conduit as these are not service conductors. My question remains -- are these conductors protected by a breaker or some overcurrent protection device. If so then there should be no problem.

Sounds like your situation is okay

We're getting mixed up here.
The question isn't if the conductors shall be encased or not.

The original question is does panel A1 require a main OCPD?

The line up is like this:
400amp meter section w/ a 400 amp main OCPD, feeding a 400 amp M.L.O. feed thru panel "A" via 400amp wire. then thru double lugs on panel "A" it feeds to a 400 amp panel "A1" via 400 amp wire.

Question;

Does panel A1 need a Main OCPD?

 

[infinity]

Wait a minuet,
There is a main breaker in the panel on the left, then you are feeding the panel on the right through lugs, Okay,

My plans are calling for a Main 400 amp breaker only at the main service , then the first panel is a feed thru panel "A" is without a Main just double M.L.O. then its jumping over to the panel on the right "A1" also with no main.
This is correct RIGHT?
Are we still talking about the same thing here?

Not if your double lugs are on the line side of the main. Feed through is what's depicted in the photo.

 

[iwire]

Is it set up like this?



Utility > 400 amp main > 400 amp conductors > 400 amp MLO 'A' > 400 amp conductors > 400 amp MLO 'A1'

 

[stuartdmc]

Is it set up like this?



Utility > 400 amp main > 400 amp conductors > 400 amp MLO 'A' > 400 amp conductors > 400 amp MLO 'A1'

Yes.

 

[stuartdmc]

Not if your double lugs are on the line side of the main. Feed through is what's depicted in the photo.

The feeders are on the Load side of the main.