Ufer ground

[Frank Samhammer]

Thanks for the replys

Thanks for the replys

I understand that you need 20' of steel or copper in the footing and that we mostly use #4 steel as a Ufer. This home is being built for a man who works for the power company and he wanted the #2 copper. after clamping the copper in the footing, I had them clamp off the copper going thru the foundation wall to assure proper grounding. I think this will utilize the footing and foundation steel as part of the ground.

 

[tryinghard]

I think what's most important is the correct application and this requires a journeyman electrician to qualify because it's our trade. What I mean with this is the electrode is often pawned off to a concrete rebar guy or plumber, in my opinion these are mistakes because the electrode has a specific purpose and non-tradesmen will not understand it's purpose therefore they will not respect its application, either during construction or after construction.

Either type CEE (ufer) can be "stubbed-up" but they do not have to be stubbed, it is wise to stub either to enable flexibility with the routing of the GEC as continuous. Often layouts change and if one simply connects #4 to rebar inside the footing as 250-68(A) allows, the #4 becomes a GEC at this point but if 20' of #4 is installed near the bottom of the footing and stubs the GEC begins at the stub point.

Residentially electricians around here have pawned off the responsibility of ufer and underground service entrance for years, this is inviting non-electricians to do electricians work! I know it's done to save trips to the site but it should stop.

The electrician will qualify (with the utility/client & contractor) the service disconnect location and with this route the GEC accordingly as well as qualify the types of electrodes needed.

 

[MarkWhite]

I think what's most important is the correct application and this requires a journeyman electrician to qualify because it's our trade. What I mean with this is the electrode is often pawned off to a concrete rebar guy or plumber, in my opinion these are mistakes because the electrode has a specific purpose and non-tradesmen will not understand it's purpose therefore they will not respect its application, either during construction or after construction.

We have cited GC's and thier re-bar subs for installing the Bare CU and clamping it to the re-bar.

Either type CEE (ufer) can be "stubbed-up" but they do not have to be stubbed, it is wise to stub either to enable flexibility with the routing of the GEC as continuous. Often layouts change and if one simply connects #4 to rebar inside the footing as 250-68(A) allows, the #4 becomes a GEC at this point but if 20' of #4 is installed near the bottom of the footing and stubs the GEC begins at the stub point.

We allow the GC to stub up the re-bar in 2 locations not less than 20' apart as long as we are provided with 20' of wire (12awg) to verify continuity.

Otherwise we need to inspect the UFER installation prior to the concrete being poured.

Residentially electricians around here have pawned off the responsibility of ufer and underground service entrance for years, this is inviting non-electricians to do electricians work! I know it's done to save trips to the site but it should stop.

Electrician's do electrical work. Bonding a piece of copper to re-bar for the sake of creating a grounding electrode system IS Electrical work.

The electrician will qualify (with the utility/client & contractor) the service disconnect location and with this route the GEC accordingly as well as qualify the types of electrodes needed.

Not quite sure what you are trying to say here.

 

[tryinghard]

We have cited GC's and thier re-bar subs for installing the Bare CU and clamping it to the re-bar.

We allow the GC to stub up the re-bar in 2 locations not less than 20' apart as long as we are provided with 20' of wire (12awg) to verify continuity.

Otherwise we need to inspect the UFER installation prior to the concrete being poured.

Electrician's do electrical work. Bonding a piece of copper to re-bar for the sake of creating a grounding electrode system IS Electrical work.

Not quite sure what you are trying to say here.

Hello Mike, The essence of what I am trying to say is the electrician needs to select the type electrode used as well as its installation not someone else. Coordination will be required between the utility co., owner and related sub contractors as well.

 

[benaround]

tryinghard, I don't see where in the NEC that a CEE can be 'stubbed up', I

can see the benefit in doing it, but to say ' either type can be stubbed up '

in my opinion is not right. After all it is called Concrete ENCASED Electrode.

I'm sure in your area it is ok to do.

 

[tryinghard]

Frank,

250.52 specifies the types of electrodes we can use, I count at least 8:

• 
  1 - Metal Underground Water Pipe
  2 - Metal Frame of the Building
  3 - CEE as rebar steel, 20' x 1/2"
  4 - CEE as #4 bare copper conductor, 20'
  5 - Ground Ring
  6 - Rod
  7 - Pipe
  8 - Plate

In other words the CEE in 250.52(A)(3) tells us we can use "at least 20' of...[re]bars...of not less than 1/2" in diameter, OR consisting of at least...#4 AWG". Either method IS the electrode, the GEC can connect to it as per 250.66

 

[benaround]

Tryinghard,

My comment was on ' stubbing up ' the rebar, 250.66 is for sizing the GEC,

but 250.68(A) the connection of the GEC shall be accessible, OK then why

the Exception No. 1: An encased or buried connection to a concrete encased,

driven, or buried grounding electrode shall not be required to be accessible.

Also,

The first line of 250.52(A)(3) " an electrode encased by at least 2" of

concrete ",

The second line, Located within and near the bottom of a concrete

foundation or footing that is in direct contact with the earth.

All I wanted to know is where does it say it's ok to STUB UP the rebar ??

 

[tryinghard]

All I wanted to know is where does it say it's ok to STUB UP the rebar ??

It doesn't but it can stub up, it also doesn't say it can't. If it is stubbed up the GEC can begin at an accessible location rather than an inaccessible location.

 

[benaround]

It doesn't but it can stub up, it also doesn't say it can't. If it is stubbed up the GEC can begin at an accessible location rather than an inaccessible location.

Ok, now we're getting somewhere. The NEC is very explict in 250.52(A)(3)

it says the " electrode " is encased, and where it is located, so IMO the

rebar that is stubbed up is not the electrode it is just rebar until it gets to

the location described in the code book, and by terminating the GEC on the

stub up it's not being terminated to the " electrode ". Now you can say it's

the same thing, but, it says what it says. Remember this is just my opinion.

 

[tryinghard]

Ok, now we're getting somewhere. The NEC is very explict in 250.52(A)(3)

it says the " electrode " is encased, and where it is located, so IMO the

rebar that is stubbed up is not the electrode it is just rebar until it gets to

the location described in the code book, and by terminating the GEC on the

stub up it's not being terminated to the " electrode ". Now you can say it's

the same thing, but, it says what it says. Remember this is just my opinion.

Frank,

I appreciate and share your opinion regarding the electrode placement. The electrode can be longer than 20' though, meaning it can rise up through a footing as a stub or run all the way to the bus (if #4 cu is used), either way #4 cu conductor can be use instead of rebar.

Around here in dwellings the contractors often have the concrete sub stub a rebar and this satisfies inspections? I have no idea how long it is or if it's installed correctly! That's my main complaint in this thread; a journeyman electrician should ONLY install these electrodes.

With this we have grown to appreciate the flexibility of connecting the GEC at the stub, but I think its best to use #4 cu conductor no matter what.