Panel Feed 800A MLO

[PanelGuy1315]

I am working on multiple projects for existing facilities where we are to add a new panelboard (iLine 800A MLO) that will be fed by a new breaker we are adding to the existing distribution panel. This new panelboard is for material handling equipment only (480v, 3ph) and will contain Qty8 30A breakers as a standard. For one particular project, our bid department only included a 50A feed to the new 800A MLO because the FLA of the equipment is only at 29A.

Is it ridiculous to feed a 800A MLO with a 50A feed? Looking through iLine catalog, I'm not necessarily seeing much smaller sizes like 100A, 150A, 200A, etc.
Do they just put a tag on the panel to derate it to 50A?

There will be plenty of available breaker slots on this thing when we are done and I just worry someone will think there is plenty of capacity to add more loads.

Thanks for your help!

 

[infinity]

For one particular project, our bid department only included a 50A feed to the new 800A MLO because the FLA of the equipment is only at 29A.

Is it ridiculous to feed a 800A MLO with a 50A feed? Looking through iLine catalog, I'm not necessarily seeing much smaller sizes like 100A, 150A, 200A, etc.
Do they just put a tag on the panel to derate it to 50A?

IMO it silly to install the 800 amp panel to begin with when the load is only 29 amps but even with the 50 amp feeder it would still be code compliant. Tagging is not required to indicate that the feeder is only 50 amps.

 

[electrofelon]

I agree with Rob, why put in an 800A panel then? Unless there is some compelling reason like future loading, yes it is ridiculous but code compliant.

 

[ron]

As long as the upstream breaker serving this 50A feeder is set to 50A, you should be good from a minimum code standpoint. You will likely have trouble terminating the #6's to the lugs in the 800A panelboard, because they are likely expecting larger conductors and not listed for #6AWG.

 

[PanelGuy1315]

As long as the upstream breaker serving this 50A feeder is set to 50A, you should be good from a minimum code standpoint. You will likely have trouble terminating the #6's to the lugs in the 800A panelboard, because they are likely expecting larger conductors and not listed for #6AWG.

Yes, that is one of the issues I've noted. The incoming lugs are 3/0-500mcm. lol

 

[SceneryDriver]

I am working on multiple projects for existing facilities where we are to add a new panelboard (iLine 800A MLO) that will be fed by a new breaker we are adding to the existing distribution panel. This new panelboard is for material handling equipment only (480v, 3ph) and will contain Qty8 30A breakers as a standard. For one particular project, our bid department only included a 50A feed to the new 800A MLO because the FLA of the equipment is only at 29A.

Is it ridiculous to feed a 800A MLO with a 50A feed? Looking through iLine catalog, I'm not necessarily seeing much smaller sizes like 100A, 150A, 200A, etc.
Do they just put a tag on the panel to derate it to 50A?

There will be plenty of available breaker slots on this thing when we are done and I just worry someone will think there is plenty of capacity to add more loads.

Thanks for your help!

Your bidding department is trying to cheap out on the job. If I were the client, I'd actually think they made a mistake if I saw a proposal like this. I certainly wouldn't accept it. It might meet code, but it's a terrible idea and I'd hate it as an end user. Someone here used to have a saying in their signature, "Not all good ideas are code enforceable."


SceneryDriver

 

[infinity]

Yes, that is one of the issues I've noted. The incoming lugs are 3/0-500mcm. lol

Just change them to smaller ones.

 

[PanelGuy1315]

I agree with Rob, why put in an 800A panel then? Unless there is some compelling reason like future loading, yes it is ridiculous but code compliant.

I've looked through the iLine catalog (HCJ) for a more appropriate sized board. I only see down to 400A. I guess that is less ridiculous. Can someone point me to another series of panelboards that would make sense? This is for 480v VFD panels. Probably needs to stay 65KA SCCR breakers. Square D NF boards, maybe?

 

[PanelGuy1315]

Just change them to smaller ones.

Thanks. I think we will do that.