Bare Copper EGC in Metallic conduit

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curt swartz

Electrical Contractor - San Jose, CA
Location
San Jose, CA
Occupation
Electrical Contractor
This is an interesting thread.

A few weeks ago we were wrapping the rough up on a large custom home on inspection day. The inspector (combo) showed up, walked in the garage and the first thing he said was...... you can't secure the bare copper GEC with steel staples....... he said steel and copper can never touch. He then walked into the house and started looking at other things.

My lead guy walked into the house with the water pipe ground clamp and asked how he was supposed to connect the copper wire to the ground clamp since the clamp has a steel screw. The inspector didn't respond.

I commented to the inspector that steel and copper touch all the time for electrical installations. I mentioned armor ground and ground pigtails to boxes. He didn't want to hear it.

I finally walked out to my truck and found some of the plastic staples with 2-nails and had my guy replace the steel staples. It took him about 5 minutes. Normally I never give in to inspectors but I didn't want to get this guys so pissed off that he takes it out on the builder. He was there to inspect electrical, plumbing, mechanical and framing.
 

iwire

Moderator
Staff member
Location
Massachusetts
6.gif

DURACLAD? TYPE MC BAG

Bare Armored Grounding Wire
Steel Interlocked Armor ? Bare Copper Ground
 

Jon456

Senior Member
Location
Colorado
Not pure water, which is chemically inert without current flow.
On the contrary, water is a natural solvent and pure water is an extremely aggressive solvent! Ultrapure water is highly corrosive and will attack stainless steel and even glass. This is because water molecules are polar, and without impurities, there is nothing to buffer their action. As the pure, polar water molecules collide with the molecules of the substance it's in contact with, they will rip those other molecules away.

However, pure water is a very good dielectric (182,000 Ohm?m).
 

kwired

Electron manager
Location
NE Nebraska
On the contrary, water is a natural solvent and pure water is an extremely aggressive solvent! Ultrapure water is highly corrosive and will attack stainless steel and even glass. This is because water molecules are polar, and without impurities, there is nothing to buffer their action. As the pure, polar water molecules collide with the molecules of the substance it's in contact with, they will rip those other molecules away.

However, pure water is a very good dielectric (182,000 Ohm?m).
I would have to agree and state that is probably why we don't really find pure water - we have to make it pure.
 

kwired

Electron manager
Location
NE Nebraska
This is an interesting thread.

A few weeks ago we were wrapping the rough up on a large custom home on inspection day. The inspector (combo) showed up, walked in the garage and the first thing he said was...... you can't secure the bare copper GEC with steel staples....... he said steel and copper can never touch. He then walked into the house and started looking at other things.

My lead guy walked into the house with the water pipe ground clamp and asked how he was supposed to connect the copper wire to the ground clamp since the clamp has a steel screw. The inspector didn't respond.

I commented to the inspector that steel and copper touch all the time for electrical installations. I mentioned armor ground and ground pigtails to boxes. He didn't want to hear it.

I finally walked out to my truck and found some of the plastic staples with 2-nails and had my guy replace the steel staples. It took him about 5 minutes. Normally I never give in to inspectors but I didn't want to get this guys so pissed off that he takes it out on the builder. He was there to inspect electrical, plumbing, mechanical and framing.

If the staples go into damp wood it might actually be a problem....
But the staple might corrode through before the wire. :)

Tapatalk!
POCO's use steel staples all the time to attach their grounding electrode conductors down the side of wood poles, and they also have the chemicals used to treat the poles to help work against them - yet the only disappearance of copper is usually because of copper thieves:happyyes:.

I have seen 50-60 year old conductors still intact on those poles, other then the surface is no longer shiny they are as good as the day they were installed.
 

kwired

Electron manager
Location
NE Nebraska
My lead guy walked into the house with the water pipe ground clamp and asked how he was supposed to connect the copper wire to the ground clamp since the clamp has a steel screw. The inspector didn't respond.

Depends on the clamp, if it is listed for direct burial that screw will be brass or stainless steel and not mild steel.
 
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