Article 250.52(3) - CEE, ( 2008 NEC )

[globe trekker]

Is a protective sleeve required to be installed at the locations in a concrete

slab-on-grade foundation, where the GEC passes thru to connect to the

footing rebar? Some graphic illustrations in the 2008 NEC Handbook have

the sleeve and some do not.

"IF" a sleeve is required, what article(s) require it, ..what type can be

installed, ..size, ...length, etc.?

Thanks!

.

 

[ICE]

250.64 is the article for installation of the GEC. There is no mention of a sleeve in the location I think you are asking about. It comes down to whether it is exposed to possible physical damage and conductor size. Most likely, what you have asked about will be concealed.

If protection is required, these are the choices: "it shall be in rigid metal conduit, intermediate metal conduit, rigid nonmetallic conduit, electrical metallic tubing, or cable armor."

 

[Bryan Holland]

From purely an electrical code standpoint, any of the three following sections could possibly be cited to require the protective sleeve:

1. 250.64(B)

2. 300.4

3. 300.5(D)(2)

 

[globe trekker]

Thanks ya'll for the relevant articles! I know that the NEC Handbook is not

"the legal standard", but Exhibit 250.23 DOES indicate a nonmetallic

protective sleeve installed to allow the passage of the GEC, whereas,

some of the other illustrations within this same article do not indicate a

sleeve.

To further clarify my question, is an approved type sleeve "required" to

protect the GEC down in to the concrete and to the point of connection

on the footing rebar, ...is the concrete mixture acidic enough to dissolve

the copper, thereby, removing an otherwise compliant GEC installation?

I seem to recall us discussing this "copper-in-contact-with-concrete"

topic some time back... :?:

.

 

[chris kennedy]

If protection is required, these are the choices: "it shall be in rigid metal conduit, intermediate metal conduit, rigid nonmetallic conduit, electrical metallic tubing, or cable armor."

If a ferrous metal enclosure (sleeve) is used it will need to be bonded as per 250.64(E).

To further clarify my question, is an approved type sleeve "required" to

protect the GEC down in to the concrete and to the point of connection

on the footing rebar, ...is the concrete mixture acidic enough to dissolve

the copper, thereby, removing an otherwise compliant GEC installation?

I find this an interesting question. 250.52(A)(3) and 680.26(B) both allow bare copper in direct contact with/in concrete. So why do the plumbers stand off their copper on masonry with plastic supports?

It appears that CMP 17 considers copper non-corrosive.

680.26(B) Bonded Parts. The parts specified in 680.26(B)(1) through (B)(7) shall be bonded together using solid copper conductors, insulated covered, or bare, not smaller than 8 AWG or with rigid metal conduit of brass or other identified corrosion-resistant metal. Connections to bonded parts shall be made in accordance with 250.8. An 8 AWG or larger solid copper bonding conductor provided to reduce voltage gradients in the pool area shall not be required to be extended or attached to remote panelboards, service equipment, or electrodes.

 

[globe trekker]

Much thanks to you all for your input!

.