NF Panelboards, E-frame breakers

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PanelGuy1315

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Electrical Designer
Wanted to get the experts opinion on this single line...

Planning to use Schneider NF Panelboard with 30A E-Frame breakers. From my understanding, in this design, the E-Frame breakers are not the branch circuit breaker because each downstream panel has it's own circuit breaker. For some reason I'm getting some hesitation from our material vendor that these E-Frame breakers are not rated for this. Something about motor loads, but these are HACR breakers made for motor loads. Plus most all loads are on the other side of a VFD.

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Your drawing shows the E-frame breakers as the branch circuit protective device.
The breakers internal to the VFD and other control enclosures are supplemental or motor protective devices, they do not need to be Listed to UL489.

While I could see an argument for calling the E-frame breakers as feeders, I have never heard anyone make it.
 
jim dungar said:
Your drawing shows the E-frame breakers as the branch circuit protective device.
The breakers internal to the VFD and other control enclosures are supplemental or motor protective devices, they do not need to be Listed to UL489.

While I could see an argument for calling the E-frame breakers as feeders, I have never heard anyone make it.
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Jim...thanks for the reply. I guess I've always heard the BCPD was the last protector before the load. Do you see an issue with the design or using E-frame breakers in general for this application?
 
PanelGuy1315 said:
Do you see an issue with the design or using E-frame breakers in general for this application?
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No. This is what they are designed to do.

Your are correct the last OCPD defines the branch circuit. The branch circuit ends at the outlet, which is usually considered as the lugs for Listed equipment such as packaged controllers.
 
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I come from the panel shop world where we built large multidoor MCPs that housed a Main CB (Molded Case CB), Power distribution block, Motor Protection CBs (140MT), VFDs. Inside that UL listed panel, we would have considered the Main Breaker and the wire down to the Power Dist Block feeder wire and the wire from the dist block to the MPCBs tap wires, the MPCB and downstream we considered the branch.
 
PanelGuy1315 said:
I come from the panel shop world where we built large multidoor MCPs that housed a Main CB (Molded Case CB), Power distribution block, Motor Protection CBs (140MT), VFDs. Inside that UL listed panel, we would have considered the Main Breaker and the wire down to the Power Dist Block feeder wire and the wire from the dist block to the MPCBs tap wires, the MPCB and downstream we considered the branch.
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That was your choice to use those terms.
The NEC does not apply to the internal wiring of Listed equipment. This is why an NEC branch circuit does not extended past that equipment's terminals.
 
PanelGuy1315 said:
. For some reason I'm getting some hesitation from our material vendor that these E-Frame breakers are not rated for this.
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Just to comment on this. Not sure what they are talking about. There is no such thing as a breaker being only rated for a branch circuit or a feeder. Sure you could get into series ratings or coordination and run into a certain circuit breaker not having the characteristics needed.
 
electrofelon said:
Just to comment on this. Not sure what they are talking about. There is no such thing as a breaker being only rated for a branch circuit or a feeder. Sure you could get into series ratings or coordination and run into a certain circuit breaker not having the characteristics needed.
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Thanks for the reply. I think they want us to use a iLine panel with PowerPact style Molded Case breakers. Its literally 3 times the cost for the same configuration. I can't determine what the Powerpact gives me over these E-Frame breakers.1743735261940.png
 
The choice between I-Line and NF is usually made based on voltages (NF is limited to 277V to ground), breaker sizing (I-Line can be 1200A), and accessories.
 
jim dungar said:
The choice between I-Line and NF is usually made based on voltages (NF is limited to 277V to ground), breaker sizing (I-Line can be 1200A), and accessories.
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I line would be needed if it were a delta system as the mentioned 277 to ground would be exceeded on one or more lines.
Also NF breakers are not made over (I believe 125 amps) so if you needed over 125 amp breakers I line is pretty much only option from Square D.
I line also has 600 volt rated breakers.

Any the breakers can be used for feeder or branch circuit. Only distinction between feeder and branch circuit is how it is used. If final OCPD before the load it is the branch circuit device.

Could possibly argue that the final device before a listed appliance or other assembly is the branch circuit device even if that appliance/assembly has additional overcurrent devices within it since NEC doesn't really address what is within that listed item.
 
jim dungar said:
The choice between I-Line and NF is usually made based on voltages (NF is limited to 277V to ground), breaker sizing (I-Line can be 1200A), and accessories.
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kwired said:
I line would be needed if it were a delta system as the mentioned 277 to ground would be exceeded on one or more lines.
Also NF breakers are not made over (I believe 125 amps) so if you needed over 125 amp breakers I line is pretty much only option from Square D.
I line also has 600 volt rated breakers.

Any the breakers can be used for feeder or branch circuit. Only distinction between feeder and branch circuit is how it is used. If final OCPD before the load it is the branch circuit device.

Could possibly argue that the final device before a listed appliance or other assembly is the branch circuit device even if that appliance/assembly has additional overcurrent devices within it since NEC doesn't really address what is within that listed item.
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The SQ D offering strikes me as odd and lacking. Granted fully rated 480 and 600V breakers are not a very huge chunk of the market, but what if I need a panel board with a bunch of smaller frame non slash rated breakers?. I've got to go to I-line for some measly 20 30 40 50 amp stuff?
 
jim dungar said:
The choice between I-Line and NF is usually made based on voltages (NF is limited to 277V to ground), breaker sizing (I-Line can be 1200A), and accessories.
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Understood. I think all of our applications will be solidly grounded 460Y/277 systems. We are still using the iLine full of 400A breakers that will feed down to the NF boards with the 30s.
 
kwired said:
I line would be needed if it were a delta system as the mentioned 277 to ground would be exceeded on one or more lines.
Also NF breakers are not made over (I believe 125 amps) so if you needed over 125 amp breakers I line is pretty much only option from Square D.
I line also has 600 volt rated breakers.

Any the breakers can be used for feeder or branch circuit. Only distinction between feeder and branch circuit is how it is used. If final OCPD before the load it is the branch circuit device.

Could possibly argue that the final device before a listed appliance or other assembly is the branch circuit device even if that appliance/assembly has additional overcurrent devices within it since NEC doesn't really address what is within that listed item.
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Yeah I think the point I was trying to make, and maybe it doesn't matter, is that our intention is not to use the E-Frame breaker as the only SC protection for like a motor starter. Even if we were feeding power to motor starters, we would still have a 140MT din rail mounted MPCB in front of the contactor acting as the short circuit protection.
 
electrofelon said:
The SQ D offering strikes me as odd and lacking. Granted fully rated 480 and 600V breakers are not a very huge chunk of the market, but what if I need a panel board with a bunch of smaller frame non slash rated breakers?. I've got to go to I-line for some measly 20 30 40 50 amp stuff?
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They do have a module that takes up same space as typical 3 pole 225 amp frame that has spaces for QO breakers within the module. Never seen them in the wild but seen them in catalog.

If you need 240 volt non slash rated they are available in QO line.

Square D does have some combination panelboards that have limited space for I line and then other section that is QO or NF breaker spaces. Can work great where you have limited larger branch/feeders and then several smaller branch circuits One of the I-Line breakers is the main for the other section I believe.
 
kwired said:
They do have a module that takes up same space as typical 3 pole 225 amp frame that has spaces for QO breakers within the module. Never seen them in the wild but seen them in catalog.

If you need 240 volt non slash rated they are available in QO line.

Square D does have some combination panelboards that have limited space for I line and then other section that is QO or NF breaker spaces. Can work great where you have limited larger branch/feeders and then several smaller branch circuits One of the I-Line breakers is the main for the other section I believe.
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But say I had an application where I needed 12 3 pole 20A 480 straight rated breakers. I would have to use I-line?
 
electrofelon said:
I've got to go to I-line for some measly 20 30 40 50 amp stuff?
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They have had the same basic offing since the late 60's, so i think they understand the needs of the majority of the market.
They make small I-Line panels for the application you mentioned.
 
jim dungar said:
They have had the same basic offing since the late 60's, so i think they understand the needs of the majority of the market.
They make small I-Line panels for the application you mentioned.
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I think we posted the same time, but take the application in post number 16. Just seems like Overkill to use I-line, at least from a size and space perspective.
 
electrofelon said:
But say I had an application where I needed 12 3 pole 20A 480 straight rated breakers. I would have to use I-line?
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How often do you find this need on ungrounded or corner grounded 480V systems? As long as the source is 277V to ground you can use NF panel even if you do not pull a neutral.
 
jim dungar said:
How often do you find this need on ungrounded or corner grounded 480V systems? As long as the source is 277V to ground you can use NF panel even if you do not pull a neutral.
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Certainly it is not very common, I am guessing that is why they don't really care about not having a great product offering for that application. Compare that to Siemens where they make up to 600 V breakers in the standard 1 in per pole configuration (i.e. NGB line).
 
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