Alwayslearningelec
Senior Member
- Location
- NJ
- Occupation
- Estimator
Anyne have a jobsite pic of the ground from the xfmr going ot building steel? Like to see how th ebuilding steel connection is made. Cadlwed? Thanks.
Xfrmr Grounded to Bldg. Steel
- Thread starter Alwayslearningelec
- Start date
- Status
- Location
- New Jersey
- Occupation
- Journeyman Electrician
We drill and tap the steel and use a hub on the end of the raceway. For a beam with a very thin flange we might drill a through hole and nut and bolt it. Cadwelding would only be if someone had it in the spec. I'll have to see if I have any photo's of the drilled steel.
Alwayslearningelec
Senior Member
- Location
- NJ
- Occupation
- Estimator
Thanks. A Myers hub or one with a flat piece?
hillbilly1
Senior Member
- Location
- North Georgia mountains
- Occupation
- Owner/electrical contractor
Use pvc and you will not need the hub. Mechanical lug bolted to the beam. (BTW, building steel is no longer considered a grounding electrode unless it is bonded to the rebar in the slab)
Alwayslearningelec
Senior Member
- Location
- NJ
- Occupation
- Estimator
We are never allowed to use PVC inside building.
hillbilly1
Senior Member
- Location
- North Georgia mountains
- Occupation
- Owner/electrical contractor
Local code or owner requirement?
Alwayslearningelec
Senior Member
- Location
- NJ
- Occupation
- Estimator
Engineer/Spec.
kwired
Electron manager
- Location
- NE Nebraska
Or has 10 feet or more in contact with earth or encased in concrete and in earth. Building steel not connected to earth in any way was never a grounding electrode.
anthonysolino
Senior Member
- Location
- Port St.Lucie Florida
check out 250.30(A)(4) this tells you your building steel is in fact a grounding electrode for a separatly derived system
I think the common practice is to drill a hole in it, nut and bolt it with lock washers via a lug.
I think the common practice is to drill a hole in it, nut and bolt it with lock washers via a lug.
anthonysolino
Senior Member
- Location
- Port St.Lucie Florida
man you wouldn't believe how many people do not remove that bonding strap and sand the paint down, it even tells you with the instructions that you need to sand it down
Alwayslearningelec
Senior Member
- Location
- NJ
- Occupation
- Estimator
So the steel has paint that need to be sanded?
anthonysolino
Senior Member
- Location
- Port St.Lucie Florida
the transformer does and I personally take a wire wheel on my impact and sand the building steel down to expose the raw metal, then when I am done with my termination I spray it with zinc primer and throw a little no lox on there
but yes typically the "red iron" has some sort of coated finish,
but yes typically the "red iron" has some sort of coated finish,
hillbilly1
Senior Member
- Location
- North Georgia mountains
- Occupation
- Owner/electrical contractor
Had one inspector years ago in the City of Atlanta make use bond to the steel plate holding the wood beams together! LOL! Sherman missed burning it down when he came through Atlanta, old furniture factory.
anthonysolino
Senior Member
- Location
- Port St.Lucie Florida
was he trying to make all the metals be the same potential? it seems odd he would request that
hillbilly1
Senior Member
- Location
- North Georgia mountains
- Occupation
- Owner/electrical contractor
He said “It was building steel” and had to be bonded! Both beams connected were wood! LOL! This was about 30 years ago, so I doubt he is still an inspector there.was he trying to make all the metals be the same potential? it seems odd he would request that
Fire code I believe
hillbilly1
Senior Member
- Location
- North Georgia mountains
- Occupation
- Owner/electrical contractor
Not unless it’s a local or state fire code. NEC does not prohibit it. Most electrical rooms do not have plenum ceilings.
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