Ufer Madness

[svaurez]

When installing a Ufer ground I usually place 20 feet of #4 in the footing and run the wire uncut back to the switchgear.

When does the concrete encased electrode end and the grounding electrode conductor begin?

 

[bennie]

Re: Ufer Madness

At the same place :roll:

 

[dereckbc]

Re: Ufer Madness

At the point where the # 4 AWG enters the concrete.

 

[pierre]

Re: Ufer Madness

Bennie

Is that the 'beginning of the end' or the 'end of the beginning'?

Pierre

[ July 14, 2003, 11:13 PM: Message edited by: pierre ]

 

[svaurez]

Re: Ufer Madness

Let's say I stubbed up a piece of re-bar instead.If the concrete encased electrode ends when it exits the concrete,the re-bar becomes a grounding electrode conductor in violation of 250.62.

 

[pierre]

Re: Ufer Madness

I believe the building code does not permit the rebar to be stubbed up out of the concrete.

Pierre

 

[don_resqcapt19]

Re: Ufer Madness

Pierre,
In many areas it is a common practice for the concrete contractor to provide a stub of rebar for the grounding electrode conductor to be connected to.
Don

 

[tom baker]

Re: Ufer Madness

Bennie is correct, the grounding electrode conductor terminates to any avaiable grounding electrode. However a ufer ground can be either 20 ft of 4 AWG bare copper or 20 ft of 1/2" rebar.
Also in Oregon state they require a Ufer ground, with a L shaped section of rebar stubbed up thru the slab. the concrete contracator does the rebar, the electrician makes the connection with a an acorn type clamp.

 

[bennie]

Re: Ufer Madness

I have made tests concerning the oxidation (rust) on rebar, and it's effect on the resistance of the earth contact. This was for RF purposes.

In Antarctica nothing oxidizes, in the Marshall Islands everything oxidizes. Even the fillings in your teeth

I have not read the findings by Herb Ufer. Does anyone know if he tested both rebar and bare copper?

 

[svaurez]

Re: Ufer Madness

If I have 20' of #4 in the footing,can I run the wire uncut up to the roof and ground several transformers with it.I was wondering if this would still be considered a UFER or would I have to apply the tap rules for a grounding electrode conductor.

 

[tom baker]

Re: Ufer Madness

Bennie I have a copy of the orginal IEEE report. The orginal test in the 1960's was done on the west coast with 4 AWG bare copper.

svaurez, you might be able to, but in the 2002 NEC there is a method for installing the grounding electrode conductor for multiple seperatly derived services, see section 250.30 A 1 b