Shipping Container Converted to Mobile Field Office

Status
Not open for further replies.
DBoone

DBoone

Senior Member
Location
Mississippi
Occupation
General Contractor
Can someone point me in the right direction on Bonding and Grounding a metal shipping container that is being converted into a construction office for use in the field.

I am using the 2011 NEC.
 
shipping containers are metal so same as metal building basically.. whole shell becomes ground plane.. if worried can connect a bonding strap to a ground rod... or 4 like the Army does..lol...
 
Has the NEC caught up with this relatively new type of installation? Are these covered under the NEC?
 
infinity said:
Has the NEC caught up with this relatively new type of installation? Are these covered under the NEC?
Click to expand...

Not really. My specs would say per NEC, but QA was the DoD, so specs were followed. Usually overkill, I could red line any assembly or process that did meet the NEC, but if more rigid specs were shown-that is what you did.
 
It is a separate structure served by electricity.

It probably needs a grounding electrode system unless you can arrange for it to be served by a single branch circuit.

The only real issue is whether it is a SDS or not.


If it is sitting on the ground the container itself probably qualifies as a GE under 2014 but not under 2017. The sneaky devils made a big change.

2014 version of 250.52(A)(2)

(A) Electrodes Permitted for Grounding.
(2) Metal Frame of the Building or Structure. The metal
frame of the building or structure that is connected to the
earth by one or more of the following methods:
(1) At least one structural metal member that is in direct
contact with the earth for 3.0 m (10 ft) or more, with or
without concrete encasement.
(2) Hold-down bolts securing the structural steel column
that are connected to a concrete-encased electrode that
complies with 2S0.52(A)(3) and is located in the support
footing or foundation. The hold-down bolts shall
be connected to the concrete-encased electrode by
welding, exothermic welding, the usual steel tie wires,
or other approved means.
Click to expand...

2017 version of 250.52(A)(2)

(A) Electrodes Permitted for Grounding.
(2) Metal In-ground Support Structure(s). One or more metal
in-ground support structure(s) in direct contact with the earth
vertically for 3.0 m (10 ft) or more, with or without concrete
encasement. If multiple metal in-ground support structures are
present at a building or a structure, it shall be permissible to
bond only one into the grounding electrode system.
Click to expand...

So you can no longer use the building structure as a GE unless it goes down into the ground at least 10 feet.
 
Never worked on them. My dad was involved in some stuff at Fort Lee and Fort Picket... Doc took him off driving for a while so I had to go get him... Lucky, was driving a base cab, but.. was first desert storm... so base very tight security... My pass did not work for his areas..lol...

While waiting for clearance checked out the logistics centers that were being sent to the desert.. they were testing them behind the computer centers.. tear down and put back up training for the riggers... helicopter pickups, and drop downs with setups... sergeants having a blast taking romeo company through its paces..lol...

General walked out with my dad, talked to the MP, and got me a letter authorizing full pass to get my dad at either base and Quantico as well...

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...
 
jumper said:
Are these permenant? Movable?

How are you supplying power?
Click to expand...

Movable

Im working with a buddy of mine on it. He owns an Industrial Steel Fabrication business and they have moved into commercial construction as well.

So im not sure how each jobsite will supply power to the panel.
 
DBoone said:
Movable

Im working with a buddy of mine on it. He owns an Industrial Steel Fabrication business and they have moved into commercial construction as well.

So im not sure how each jobsite will supply power to the panel.
Click to expand...

So this still planning stage?

I would be thinking of a model similar to mobile homes with outside disco attached. Easiest to reconfigure.
 
jumper said:
So this still planning stage?

I would be thinking of a model similar to mobile homes with outside disco attached. Easiest to reconfigure.
Click to expand...

Building stage. Finish framing inside in the morning and then rough in electric.

You know, make it up as you go.
 
DBoone said:
Building stage. Finish framing inside in the morning and then rough in electric.

You know, make it up as you go.
Click to expand...

Okay, totally cowboy production, not a problem.

What interior wiring methods are you using?

Are you planning to be prepared for both POCO and genny? SDS or not?

Interior or exterior panels?

Power inlets?
 
jumper said:
Okay, totally cowboy production, not a problem.

What interior wiring methods are you using?

Are you planning to be prepared for both POCO and genny? SDS or not?

Interior or exterior panels?

Power inlets?
Click to expand...


Interior panel nippled through the container wall to large junction box mounted on exterior.

4-wire from junction box to panel. Wire panel like a sub.

Can we lug a 6awg copper to inside wall of container and land on ground bar for Bonding?

He said with the junction box he has the option to make a splice in the box to get power from onsite or run SO cord from box and plug in to outlet if one is provided.

Inside is NM and plastic boxes.

Mini Split, a couple of lights and some receptacles will be only things supplied.
 
DBoone said:
Interior panel nippled through the container wall to large junction box mounted on exterior.

4-wire from junction box to panel. Wire panel like a sub.

Can we lug a 6awg copper to inside wall of container and land on ground bar for Bonding?

He said with the junction box he has the option to make a splice in the box to get power from onsite or run SO cord from box and plug in to outlet if one is provided.

Inside is NM and plastic boxes.

Mini Split, a couple of lights and some receptacles will be only things supplied.
Click to expand...

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?
 
Status
Not open for further replies.
Top