Copper-Aluminum GEC

ccurrins · July 30, 2011, 8:40pm

at same grounding clamp. Is this dual rated?

jpope · July 30, 2011, 10:13pm

I don’t know if the lug is rated for multiple conductors, but it appears you have tinned-copper rather than aluminum.

mboyett · July 30, 2011, 11:09pm

The grounding electrode must be installed in one continuous length without a splice or a joint, unless spliced by an irreversible compression-type connector listed for the purpose or by an exothermic welding process.

ccurrins · July 30, 2011, 11:14pm

Thanks Michael, wanting to be sure this is not a connector I wasn’t familiar with.

Jeff you’re correct, it’s tinned-copper.

mboyett · July 30, 2011, 11:19pm

It’s a moot point. The IRC and NEC prohibit GEC splices:

E3510.1 Continuous. The unspliced grounding electrode conductor shall run to any convenient grounding electrode available
in the grounding electrode system, or to one or more
grounding electrode(s) individually. The grounding electrode
conductor shall be sized for the largest grounding electrode
conductor required among all of the electrodes connected to it.

Commentary:The grounding electrode conductors are to be
unspliced to achieve the greatest reliability and continuity
(see Section 250.64(C) of the NEC). Where electrodes
are connected together to a common electrode
conductor, the largest required size of the conductors
will dictate the size of the common conductor. For example,
if a 6 AWG conductor ran from the service to a
ground rod and a 4 AWG conductor was required to
connect the ground rod to the footing steel, the 6 AWG
conductor would have to be upsized to a 4 AWG.

ccurrins · July 31, 2011, 12:11am

Thanks

rmeier2 · July 31, 2011, 3:24pm

Do you have a photo of this installation? You need to be careful when determining what’s actually a GEC and what’s a bonding jumper. Only the GEC is required to be continuous. You can use bonding jumpers to interconnect all of the electrodes that are part of the grounding electrode system. Here’s a few examples:

http://www.mikeholt.com/onlinetraining/page_images/1113920706_2.jpg

http://www.mikeholt.com/onlinetraining/page_images/1113918256_2.jpg

ccurrins · July 31, 2011, 5:12pm

Starts with white cloth cable in photo 1.

Also a view of the mixture of panels.

rmeier2 · July 31, 2011, 5:16pm

Yes that’s a violation in photo #3. You have bare copper and tinned copper which is fine, however your splicing of the GEC is required to be irreversible. Also it is not permitted to use that lug in that fashion with two conductors. I see some other problems with the length of the SE cable to the panel on the left.

ccurrins · July 31, 2011, 5:24pm

Thanks Robert, that was my original question. I deleted the photo. The service entrance and main panel installed in 1960.

With photo at left (main panel) where bare copper and tinned copper is under same lug, that’s also a violation, correct?

rmeier2 · July 31, 2011, 6:08pm

Yes, here’s the code references:

110.14 Electrical Connections.
Because of different characteristics of dissimilar metals, devices such as pressure terminal or pressure splicing connectors and soldering lugs shall be identified for the material of the conductor and shall be properly installed and used. Conductors of dissimilar metals shall not be intermixed in a terminal or splicing connector where physical contact occurs between dissimilar conductors (such as copper and aluminum, copper and copper-clad aluminum, or aluminum and copper-clad aluminum), unless the device is identified for the purpose and conditions of use. Materials such as solder, fluxes, inhibitors, and compounds, where employed, shall be suitable for the use and shall be of a type that will not adversely affect the conductors, installation, or equipment.
FPN: Many terminations and equipment are marked with a tightening torque.
(A) Terminals. Connection of conductors to terminal parts shall ensure a thoroughly good connection without damaging the conductors and shall be made by means of pressure connectors (including set-screw type), solder lugs, or splices to flexible leads. Connection by means of wire-binding screws or studs and nuts that have upturned lugs or the equivalent shall be permitted for 10 AWG or smaller conductors.
Terminals for more than one conductor and terminals used to connect aluminum shall be so identified.

ccurrins · July 31, 2011, 11:13pm

Thanks for the info.

kwood · July 31, 2011, 11:47pm

They do have one that is designed for Linking the grounds and they have a separator between each GEC. Never payed attention to the company name on them. Do you know Robert Meier?
You find it in encased situations in concrete. I think it is called a Servit.

rmeier2 · August 1, 2011, 12:26am

There are only two permissible types of products available to splice a GEC, one is an irreversible compression splice and the other is an exothermic welding (Cadweld) splice.

I believe that you’re referring to a split bolt that has a separator which would sit in between the two conductors. Those typically would be used when splicing aluminum and copper. That type wouldn’t be required here since the to conductors are both copper nor permitted due to the only types allowed as previously mentioned.

kwood · August 1, 2011, 12:35am

Correct. What is the name of the one I am refering to?
Electrical has always been my week spot in Home Inspection.
The reason is I seem to not be able to wrap my head around the confusion as the wire # system. I have talked to electricians and they can’t figure out why they did it this way either.
Is there a reason?
One more point Robert don’t forget I am from Canada.

rmeier2 · August 1, 2011, 8:54am

Yes, Servit is a brand name for a split bolt connector that is made by Burndy. Although they are permitted to be used for taps to the GEC they are not permitted to be used for splicing the GEC.

http://www.farwestcorrosion.com/images/fwst19/servit05.gif

kwood · August 1, 2011, 11:53am

Robert:

I know the name of that one. The one I am talking about has a separating shim in the middle that is used for two different size GEC’s
What is it called?
One is split bolt single wire. The other is two wire.
Same company but different name and application.

roconnor · August 1, 2011, 6:43pm

You might be thinking about a Burndy “Tritap Servit” universal split bolt connector made for all combinations of copper and aluminum connections … that looks like this …

http://http.cdnlayer.com/ec1images/raw/products/2010/3004223_022511l_shub.jpg

The American Wire Gauge (AWG) system has been used in the US and CAN since around 1857. This gauge system originated in the number of drawing operations used to produce a given gauge of wire. Very fine wire (for example, 30 gauge) requires more passes through the drawing dies to make it thinner than 0 gauge (1/0) wire. When larger wire was needed they went to 00 gauge (2/0), 000 gauge (3/0) and 0000 gauge (4/0) in increasing size. Above that is “kcmil” or thousands of circular mils, which relates to wire area.

Hope that helps …

roconnor · August 1, 2011, 6:44pm

RM … nice graphics to explain the differences. I always liked the Mike Holt figures, and his guide books with those diagrams are excellent …

kwood · August 1, 2011, 7:21pm

Thanks Robert:

That is the one I was looking for.