OEM commissioning and NFPA70E

[paulbr]

Our company is OEM. We are making large industrial equipment (600-800amp, 480VAC). Before this equipment is shipped to the customer it is assembled and commisioned in the house. Up till now we were feeding our main enclosure through the open door. Therefore during all commissioning time we were having energized panel with door not closed.
Now days we are trying to enforce NFPA70E including Personal Protection Equipment (PPE). To be able to do start up you need to dress like spaceman if you keep feed the panel through the door openning.
I am wondering how other people addressing this issue. Let's say if we make cut out in enclosure to feed cable through it and after start up is completed will close this cut out. Will we compromise enclosure rating? Are there some standard flanges the may be used for this purpose? Most of our enclosures are Hoffmann and we do not know where exactly power cable will penetrate enclosure at customer site.
Please, share your experience.

PaulBr.

 

[Open Neutral]

Must you be within "target distance" when testing?

Are all cabinets the same size? Can you build one door with holes, and temporarily put it on the cabinet?

 

[jim dungar]

Have you actually calculated the incident energy at your panels?

 

[Jraef]

One thing you can look at is changing your enclosures to use ones that have a removable base plate and an option for using what is called a "plinth base". This is a short (usually 6") base with removable side and/or front covers that you place the enclosure on top of. So you can route your temporary cables through sealing connectors on the removable base and exit from one of the removable covers on the plinth. Then when testing is done, supply a new enclosure base without holes in it for the installing contractor. They will probably appreciate it because having that removable base plate makes it easier to punch for conduit entry.

Example of a plinth base:

 

[kingpb]

Have you actually calculated the incident energy at your panels?

I agree this would be the most appropriate first step.

Second step, find the solution based on first step results.

Either way, I think you would still want to utilize NEC for minimum temp power requirements.

 

[paulbr]

Thanks for all suggestions.
Jraef,
Would you, please, provide few names of the enclosure manufacturers, who makes such panels with removable base plate?
kingpb,
What articles in NEC are attributed to temp power requirements?

Thank you.

 

[steve66]

I agree this would be the most appropriate first step.

Second step, find the solution based on first step results.

Either way, I think you would still want to utilize NEC for minimum temp power requirements.

I'll third that response. With 800A, it seems like you could add some uprstream protection that would get the arc flash down to a more reasonable level - something that doesn't require a spacesuit.

I'd also suggest you consider what happens once the equipment is acutally installed at the customers sites. Is the startup something that might have to be preformed again? Are your field guys going to have to carry arc-flash suites with them?

Just wondering if this is somethiing that can be easily changed. Just for example, like by moving adjustment pots to a small access door.

 

[Jraef]

Thanks for all suggestions.
Jraef,
Would you, please, provide few names of the enclosure manufacturers, who makes such panels with removable base plate?

Hoffman, Rittal, Hammond, Saginaw, all of the major manufacturers offer them now. That picture is from Rittal.