Rules for a mobile laboratory

[BAHLONGSHOT]

Hi, I am building a mobile laboratory that will have its own generator and plumbing and will need to be able to hook to an external source of power at times. I haven't had much luck in figuring out the legalities with the type of transfer (or if legal a double throw switch) I can use and the correct distancing from panel to panel if I install more then one electrical panel. I looked in The NEC and found a small area that discusses these types of things but it didn't really cover much. Is there anyone available that has experience in this area? Thank you in advance.

 

[Megawatt]

Hi, I am building a mobile laboratory that will have its own generator and plumbing and will need to be able to hook to an external source of power at times. I haven't had much luck in figuring out the legalities with the type of transfer (or if legal a double throw switch) I can use and the correct distancing from panel to panel if I install more then one electrical panel. I looked in The NEC and found a small area that discusses these types of things but it didn't really cover much. Is there anyone available that has experience in this area? Thank you in advance.

Bahlongshot welcome to the forum and what size is your generator so I can get an idea on how much current you will be pulling and I’m assuming that you have a panel and what size on your mobile laboratory. Is the generator hard wired or does it have a plug

 

[BAHLONGSHOT]

Bahlongshot welcome to the forum and what size is your generator so I can get an idea on how much current you will be pulling and I’m assuming that you have a panel and what size on your mobile laboratory. Is the generator hard wired or does it have a plug

Hi thanks for the response, My generator is an 80 kw 12 tap setup for single phase. I was intending to hard wire the generator to a main disconnect but also need a way to attach a plug to use for external power without the generator.

 

[Megawatt]

Hi thanks for the response, My generator is an 80 kw 12 tap setup for single phase. I was intending to hard wire the generator to a main disconnect but also need a way to attach a plug to use for external power without the generator.

Is the 80kw At 240vac that’s over 300 amps. I don’t know of a plug rated for that much amperage and do you really need 300 amps. Are you seriously going to be pulling that kind of current, if so you need to install a 400 amp main breaker panel on the outside of your laboratory to make these connections

 

[BAHLONGSHOT]

Is the 80kw At 240vac that’s over 300 amps. I don’t know of a plug rated for that much amperage and do you really need 300 amps. Are you seriously going to be pulling that kind of current, if so you need to install a 400 amp main breaker panel on the outside of your laboratory to make these connections

Yes you are correct with the amperage and yes I will be pulling between 250 and 300. It will take too long to get a 400 amp main panel fabricated during these times so I wanted to use two 200 amp panels, Which is one of the areas I'm kinda stuck at.I dont know what kind of distance I would be required to put between the panels.

 

[Megawatt]

Yes you are correct with the amperage and yes I will be pulling between 250 and 300. It will take too long to get a 400 amp main panel fabricated during these times so I wanted to use two 200 amp panels, Which is one of the areas I'm kinda stuck at.I dont know what kind of distance I would be required to put between the panels.

To my knowledge there is no distance between panels. Think of it like buildings where you have a subfed panel which in my experience some buildings are 100 feet from the main panel and I don’t think that you are going to be that far. You are just wanting to put both on your laboratory. You need to consider the tap rule and will have to install to have a 24x24x12 junction box at a minimum which really needs to be between the two 200 amp panels. You can splice three 3/0 wire and one # 6 ground wire to each panel. As far as the 400 amp junction box you will need 350 MCM wire and all the sizes are THWN copper wire using 75 Degree C table. Article 310.15(b)(16) of the NEC. You will also have to have 2 ground rods to bond the neutral bar on both panels. I designed it for you so good luck. If you have any more questions please come back and let’s us know how it works out and a picture would be nice.

 

[BAHLONGSHOT]

To my knowledge there is no distance between panels. Think of it like buildings where you have a subfed panel which in my experience some buildings are 100 feet from the main panel and I don’t think that you are going to be that far. You are just wanting to put both on your laboratory. You need to consider the tap rule and will have to install to have a 24x24x12 junction box at a minimum which really needs to be between the two 200 amp panels. You can splice three 3/0 wire and one # 6 ground wire to each panel. As far as the 400 amp junction box you will need 350 MCM wire and all the sizes are THWN copper wire using 75 Degree C table. Article 310.15(b)(16) of the NEC. You will also have to have 2 ground rods to bond the neutral bar on both panels. I designed it for you so good luck. If you have any more questions please come back and let’s us know how it works out and a picture would be nice.

I owe you a huge thankyou and yes I will deliver some pictures when its complete. Its framed up with all heavy steel tubing and weighing in at 25k lbs right now just with the frame and axles. This thing is going to be a beast. Again Thankyou!
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I owe you a huge thankyou and yes I will deliver some pictures when its complete. Its framed up with all heavy steel tubing and weighing in at 25k lbs right now just with the frame and axles. This thing is going to be a beast. Again Thankyou!

Oh one last thing. If I cant find a plug that'll work I suppose I could just hard wire it at each site when needed. But for the transfer switch. Is it legal to just use a double throw?

 

[Megawatt]

I owe you a huge thankyou and yes I will deliver some pictures when its complete. Its framed up with all heavy steel tubing and weighing in at 25k lbs right now just with the frame and axles. This thing is going to be a beast. Again Thankyou!
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Oh one last thing. If I cant find a plug that'll work I suppose I could just hard wire it at each site when needed. But for the transfer switch. Is it legal to just use a double throw?

Yes I would advise you to use a double throw switch so it would be impossible for 2 different power sources. I think I told you that they don’t make plugs that big. Good luck my friend and keep in touch
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Yes I would advise you to use a double throw switch so it would be impossible for 2 different power sources. I think I told you that they don’t make plugs that big. Good luck my friend and keep in touch

Please bond the steel tubing on you laboratory which is a requirement per the NEC article 250

 

[BAHLONGSHOT]

Yes I would advise you to use a double throw switch so it would be impossible for 2 different power sources. I think I told you that they don’t make plugs that big. Good luck my friend and keep in touch
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Please bond the steel tubing on you laboratory which is a requirement per the NEC article 250

Thank you again!

 

[Megawatt]

Thank you again!

You are quite welcome and I read your profile which allowed me to advise you but please be careful