Shipping Container Converted to Mobile Field Office

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jumper said:
Get rid of junction box, use disco.

Bonding jumpers are sized per size of entrance conductor, 250.102. You are gonna more than just interior wall. Frames, beams, chassis,etc.

NM and plastic boxes are fine.

He, not being an electrician, is why these units get miswired and people get killed.

100A 120/240V?
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I haven't looked closely yet but assumed the walls, beams, etc were all connected so Bonding to the wall would bond the entire enclosure.

120/240 and was thinking either a 60A or 100A panel

Mini-Split is 208/230V , MOCP 15, MCA 7.95 so will use 14-2 on double pole 15A breaker

I will look at 250.102 to size Bonding jumper

How would you set up your disco and panel. What size and what wiring method
 
Aren't these things a big box that's all welded together? I think you just need to bond the container once. Other separate stuff you install inside the container, that may need additional bonding.
 
Adamjamma said:
Noticed sergent getting on them to quickly run ground rods at each corner and bond as soon as helicopter took off, before even opening the doors to get the cables run to the generators... gensets also grounded at four corners with ground rods.... never found out why, though...just noticed they always did it...
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Probably to assure earth around equipment at same potential to minimize touch hazard.
 
jaggedben said:
Aren't these things a big box that's all welded together? I think you just need to bond the container once. Other separate stuff you install inside the container, that may need additional bonding.
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That's been my thinking this whole time. But knew I could have missed something. Was thinking we could just bond to any part of the frame, I chose the wall, and land conductor on ground bar.
 
DBoone said:
That's been my thinking this whole time. But knew I could have missed something. Was thinking we could just bond to any part of the frame, I chose the wall, and land conductor on ground bar.
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I have no idea about Adam’s four point grounding but we did do two. Overkill.

Welds break, stuff happens, we bonded at a minimum of four points in the units and took them a central ground stud/bar.
 
jumper said:
Do you wish to be genny and POCO ready and how much money you got? I worked for Uncle Sam doing these units so I may not be real cheap in design.
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I'd like to roll up in the morning and blow his mind with such an amazing, well thought out set up
 
Torch indeed. Three windows and one entry door.

Looked around the big orange store this afternoon and didn't see a 60A disconnect/main breaker like I want to install on the outside wall. Everything was Main Lugs.

I want to mount the disconnect/main outside and conduit thru the wall into a 60A sub panel. Run 4-wire from outside disconnect to panel. Bond trailer enclosure, rough in everything and call in the spray foam.

Anybody have any links to the type of disconnect I'm talking about?

Anybody have a better idea?
 
Went to supply house today and told them what we were doing. Ended up getting a Siemens 125 amp outdoor loadcenter (catalog number W0408ML1125) and a Siemens 125 amp indoor loadcenter (catalog number E0816ML1125F/E0816ML1125S)

Both are Main Lugs as you can see in the catalog number.

Bring in power from on site into outdoor panel, land on Line A,B,N

Attach Bonding strap from N to panel enclosure.

Install 60 amp breaker in outdoor panel and run 6 awg 4-wire feeder between breaker and main Lugs on indoor panel.

Bond 6 awg solid copper to inside container wall, thru knockout in indoor panel and land on EGC bar.


Outdoor panel will have 2 breaker spaces still available if they ever want to add a receptacle outside or anything. As long as the breaker ratings total don't exceed 125 amps

So N/EGC will be bonded together and to enclosure in outdoor panel and will be separate, with floating neutral, indoors. Typical subpanel set up

Will everything I described be fine?
 
I don't think you will find a load center under 125A. You may but I doubt it. Besides as cheap as the 125A are why bother with trying to find something else?

It doesn't matter if the breaker sizes add up to more than 125A, that's not how you do that. You base it on the load not on the breakers. Go to any 40 or 42 space 200A panel and add up the breakers. You will, in most cases, go way over the 200A rating of the panel.

HVAC- 90A
Range- 50A
Dryer- 30A
WH - 30A
200A total of these without even counting the 15/20A branch circuits.
 
Little Bill said:
I don't think you will find a load center under 125A. You may but I doubt it. Besides as cheap as the 125A are why bother with trying to find something else?

It doesn't matter if the breaker sizes add up to more than 125A, that's not how you do that. You base it on the load not on the breakers. Go to any 40 or 42 space 200A panel and add up the breakers. You will, in most cases, go way over the 200A rating of the panel.

HVAC- 90A
Range- 50A
Dryer- 30A
WH - 30A
200A total of these without even counting the 15/20A branch circuits.
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Thanks for the response Bill. Just to clarify, I understand that it's based on load and not the breaker rating. What I meant by my statement was that in the outside panel, the power is coming in from somewhere else. Potentially it could be fed from a breaker larger than 125. And since the outdoor panel is Main Lug and has no 125 amp Main to protect it from overload then if our breakers in outdoor panel total more than 125 amps there is a possibility that we could draw more than 125 amps without tripping any OCPD from the power source and overload our panel.

Correct me if I'm off base on that thinking.

Our indoor panel, and anything else that would be fed from outdoor panel are no concern because we know we have proper OCP
 
By code a separate structure is supposed to have a disconnecting means anyway, so it makes sense to simply put a 60A breaker into the panel. You need a hold-down kit. All you need to do is to read the panel label to figure out the correct position and the part# for the hold down kit. Install per instructions, label it 'MAIN'. Anyone hooking it up who knows what they're doing should understand where they're supposed to land the feed. Having the 60A breaker there tells them what the max expected load is, too.
 
jaggedben said:
By code a separate structure is supposed to have a disconnecting means anyway, so it makes sense to simply put a 60A breaker into the panel. You need a hold-down kit. All you need to do is to read the panel label to figure out the correct position and the part# for the hold down kit. Install per instructions, label it 'MAIN'. Anyone hooking it up who knows what they're doing should understand where they're supposed to land the feed. Having the 60A breaker there tells them what the max expected load is, too.
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See if I understand you correctly. We need a disconnect to our structure by code so instead of landing incoming power on the main lugs and then having a 60amp breaker installed which we run our feeder off of that breaker to the inside panel, you say I should install a 60 amp breaker outside with a hold down kit and label it MAIN. Incoming power would obviously land there and we have OCP to protect our panel and to serve as main disconnect.

Then below that, in the last 2 breaker slots install another 60 amp breaker and run our feeder off of that.
 
DBoone said:
Thanks for the response Bill. Just to clarify, I understand that it's based on load and not the breaker rating. What I meant by my statement was that in the outside panel, the power is coming in from somewhere else. Potentially it could be fed from a breaker larger than 125. And since the outdoor panel is Main Lug and has no 125 amp Main to protect it from overload then if our breakers in outdoor panel total more than 125 amps there is a possibility that we could draw more than 125 amps without tripping any OCPD from the power source and overload our panel.

Correct me if I'm off base on that thinking.

Our indoor panel, and anything else that would be fed from outdoor panel are no concern because we know we have proper OCP
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If you (or someone) is feeding a 125A panel with more than a 125A feeder than that is a violation to begin with. You can't feed another panel with more than the rating of the panel. You can feed the same or less but not more.
 
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