When a New Bldg.(industrial)is constructed with steel eye beams, does the connection to the beams need to be above ground level (not buried). I've seen a lot of Bldgs. with the exothermic connection above the ground. Is it by Code, to have them accesible? Or can this connection be below grade? Thanks - Good Day
Oddly enough, this seems to be addressed in the 2011 changes. It appears that simply having the mounting bolts of the columns in the concrete is enough- and if they're tied to the rebar with ordinary tie wire, that's certainly enough.
That sadi, I've only given the changes a quick review, and have not reviewed the code in any detail - so my understanding my be incomplete.
SJT: Having the GEC (earth) connection visable for the electrical inspector may be a concern. A lot of times, the footings, etc., are already backfilled before any elec inspections are called for.
Here in NJ, the Building Inspector IS required to inspect the ufer connection(s) when he does footing/foundation inspection(s).
Also, keep in mind that the electricians may not be 'on site' for the footings/foundations to install any grounding. Additionally, there may be changes in locations, or a GEC installed at a 'wrong' location.
The last time I faced this issue I bonded to the big steel above ground.
It was no hassle, and a cheaper procedure.
Because of water bonding and gas bonding, above ground bonding was in the plans.
Jumping over a couple of feet to clamp the big steel was no effort.
I'm scratching my head trying to figure out why you'd be so interested in having this bond done underground. From my experience, it would almost always be more expensive. Only exothermic or listed trick connectors would meet Code. By comparison it's quick and cheap to 'tag' the big iron above ground - usually in the electrical room -- or right next door.