Panel Main Breaker

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Misheru

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I'm new here so hello! :D

I need some clarification on this:
I have a 200A, 120/208V, 3Ø, 4W panel without a main breaker, fed from a distribution panel with a 200A, 3P OCPD. The 200A panel is sub-feeding (4) 100A panels and has (6) additional spare breakers. Please correct me if I'm wrong but I believe this is a code violation. The total rating of all the circuit breakers is 690A. When I do design, if the total rating of the C.B.'s are greater than the panel rating, a main breaker is required. But I couldn't find any specific code section stating this. Can someone please shed some light? :? Thank you!
 
is demand greater than 200 amps or is the circuit breakers?
On here have often seen 320 amp main panel serving 2 200 amp sub panels.

need to calculate actual demand versus maximum demand.
At least, that is what I am being taught- Maximum demand and diversity.
 
You do not need a main breaker in the panel when the feeder OCPD is protecting the entire feeder. The OCPD for the panel can be at the beginning of the feeder and is not required to be in the panel. Also adding the OCPD values in the panel provided you with no real picture of what the actual load is.

Welcome to the Forum. :)

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.
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Misheru said:
I'm new here so hello! :D

Thank you!
Click to expand...

Assuming there is a known calculated load for the feeder supplying the 200 amp main lug panel that load should not exceed the rating of the main lug panel.
There is no issue with the main lug panel being provided with overcurrent protection at the supply side of the 200 amp feeder


Edit

408.30 General.
All panelboards shall have a rating not less than the minimum feeder capacity required for the load calculated in accordance with Parts II, III, IV, or V of Article 220 as applicable.
 
Adamjamma said:
is demand greater than 200 amps or is the circuit breakers?
On here have often seen 320 amp main panel serving 2 200 amp sub panels.

need to calculate actual demand versus maximum demand.
At least, that is what I am being taught- Maximum demand and diversity.
Click to expand...

You can calculate all you want, but still, a 200a rated panel fed from a 200a rated OCPD is not a code violation.

JAP>
 
Adamjamma said:
here have often seen 320 amp main panel serving 2 200 amp sub panels.

.
Click to expand...

jap said:
You can calculate all you want, but still, a 200a rated panel fed from a 200a rated OCPD is not a code violation.

JAP>
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I would assume what he was getting at is the presence of breakers exceeding the ratting of the 200 amp panel does not mean the rating of the panel is exceeded

he most likely just is not saying with your flare
 
david said:
I would assume what he was getting at is the presence of breakers exceeding the ratting of the 200 amp panel does not mean the rating of the panel is exceeded

he most likely just is not saying with your flare
Click to expand...

at least someone seems to understand me..lol...I just gotta learn to speak correctly
 
I don't think the reasons why a main breaker is actually required was ever addressed.

If it was because of the total ratings of the individual branch breakers in the panel exceeding the rating of the panel as the OP indicated, we'd be in trouble.


JAP>
 
It seems the OP thinks a Main is required in the subpanel because the ratings of the individual branch breakers exceed the panelboard's rating.

That's not a reason to feel like a second main needs to be installed in the subpanel.


JAP>
 
ActionDave said:
Posts 2,3,4 covered that.
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Post #2 was about a need to calculate the demand
Post #3 was about not needing a main in the panel because there was an OCPD upstream
Post #4 was about the calculated load not exceeding that of the panel.

None of these gives him a reason of when and why a Main OCPD is required to be installed in a panel.

JAP>
 
The breaker in the distribution panel is the "main" for this sub panel.

If the sub panel were in a separate building, then the six disconnecting means rule for the building applies and a main would be needed at the second building - still doesn't mean it has to be in the panel though, just is what is often preferred.
 
david said:
Assuming there is a known calculated load for the feeder supplying the 200 amp main lug panel that load should not exceed the rating of the main lug panel.
There is no issue with the main lug panel being provided with overcurrent protection at the supply side of the 200 amp feeder


Edit

408.30 General.
All panelboards shall have a rating not less than the minimum feeder capacity required for the load calculated in accordance with Parts II, III, IV, or V of Article 220 as applicable.
Click to expand...


Total connected load is unknown and that's the reason I think a main breaker is needed/required(?)
Thank you.
 
jap said:
Post #2 was about a need to calculate the demand
Post #3 was about not needing a main in the panel because there was an OCPD upstream
Post #4 was about the calculated load not exceeding that of the panel.

None of these gives him a reason of when and why a Main OCPD is required to be installed in a panel.

JAP>
Click to expand...


Total connected load is unknown :happysad:
Thank you :)
 
Misheru said:
Total connected load is unknown :happysad:
Thank you :)
Click to expand...

I thought you were needing to know when a Main was needed or not in a panel.

The ratings of the individual branch breakers exceeding the rating of the panelboard is not a reason a main would be needed.


JAP>
 
If a main was needed when the ratings of the branch breakers exceeded the ratings of a panelboard, (For Example) we'd have to install a 100 amp main breaker in a 100 amp rated panel every time one had only (6) 1p 20 amp breakers in it.
That's simply not the case.

JAP>
 
Misheru said:
Total connected load is unknown and so I'm taking the total ratings of the circuit breakers in that panel.
Click to expand...
First, you can't just add up breakers, that tells you nothing. If there is no information about the connected loads the NEC has formulas to calculate a loads.

Second, the 200A breaker feeding the panel is protecting the conductors and panel, so a main breaker at the panel is redundant.
 
electrofelon said:
Not required. Think about it: what would a 200 amp breaker mounted IN the panel do that a 200 amp breaker mounted at the source of the feeder not do?
Click to expand...

He's not talking about that.

He knows it needs a Main OCPD for the panel. He's talking about needing a 2nd main at a subpanel just because the ratings of the branch breakers exceed the rating of the panelboard.

Not so.

You don't count up the amperage that's printed on the face of the breakers, and, if it exceeds the panel rating throw a Main Breaker in for good measure.

JAP>
 
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