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#100661 12/08/06 09:20 PM
Joined: Jul 2004
Posts: 35
K
kencr Offline OP
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I am actually building my own garage, and I have not bonded rebar in a footing before .. most times it is done by the concrete crew ?? I assume that .. not sure.

Any way ... what type of clamp is approved for that ? And what size copper wire ? # 6 bare I am guessing. The garage will have a 100 amp sub panel feed from the house panel.
Thanks for your replies

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#100662 12/08/06 09:26 PM
Joined: Jul 2004
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G
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4ga solid and any clamp listed for burial in concrete and connection to rebar. The bronze one they use in pools is common and Erico has a bronze acorn that works


Greg Fretwell
#100663 12/09/06 06:12 AM
Joined: Jan 2003
Posts: 4,391
I
Moderator
We use bare stranded, much easer to work with.


Bob Badger
Construction & Maintenance Electrician
Massachusetts
#100664 12/09/06 09:41 AM
Joined: Nov 2000
Posts: 2,148
R
Member
gfretwell,
Quote
4ga solid and any clamp listed for burial in concrete and connection to rebar.
Why #4?
Don


Don(resqcapt19)
#100665 12/09/06 04:21 PM
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250.66(B)Connections to Concrete-Encased Electrodes. Where the grounding electrode conductor is connected to a concrete-encased electrode as permitted in 250.52(A)(3), that portion of the conductor that is the sole connection to the grounding electrode shall not be required to be larger than 4 AWG copper wire.


Greg Fretwell
#100666 12/09/06 05:03 PM
Joined: Dec 2000
Posts: 4,294
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But that doesn't say that it cannot be smaller than #4, only that it needn't be larger.

#100667 12/09/06 06:14 PM
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G
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I agree but when you are casting something in concrete for your own house, why cheap out?
By the time you add physical protection for a smaller size you probably haven't saved any money anyway.


Greg Fretwell
#100668 12/09/06 08:37 PM
Joined: May 2003
Posts: 2,876
E
e57 Offline
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Another reason to go for #4. It seems to fit in a portion of this code between (*) pysical damage, and severe physical damage.

Quote
250.64(B) Securing and Protection from Physical Damage. A grounding electrode conductor or its enclosure shall be securely fastened to the surface on which it is carried. A 4 AWG copper or aluminum or larger conductor shall be protected if exposed to severe physical damage. (*) A 6 AWG grounding conductor that is free from exposure to physical damage shall be permitted to be run along the surface of the building construction without metal covering or protection where it is securely fastened to the construction; otherwise, it shall be in rigid metal conduit, intermediate metal conduit, rigid nonmetallic conduit, electrical metallic tubing, or cable armor. Grounding conductors smaller than 6 AWG shall be in rigid metal conduit, intermediate metal conduit, rigid nonmetallic conduit, electrical metallic tubing, or cable armor.

[This message has been edited by e57 (edited 12-09-2006).]


Mark Heller
"Well - I oughta....." -Jackie Gleason
#100669 12/10/06 01:15 AM
Joined: Nov 2000
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The code would permit a #8 GEC for this application. The #4 is the maximum required by the code for a GEC to a concrete encased electrode, but Table 250.66 applies and the use of smaller conductors is permitted. The smaller wire may not require and physical protection. It could be stubbed up in a stud space and run to the panel. If there is a wall finish no additional protection would be required.
Don


Don(resqcapt19)

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