bonding sleeve

Status
Not open for further replies.
stew said:
when protecting the gec using emt does the emt have to be connected by bonding back to the conductor? if so why?
Click to expand...

Yes.

It's a bit over my head but if you do not bond the EGC to the steel raceway if a fault happens you end up with a high impedance fault path.

Some people call it a choke, but regardless of what you call it the GECs effectiveness will be reduced without the proper bonding
 
Art. 250.64 (E) I think you bond the raceway to ensure the raceway and conductor are in parallel with each other...


1100205275_2.jpg
 
Last edited:
Ferrous and non-ferrous metals
From Wikipedia, the free encyclopedia
Jump to: navigation, search

One method of classifying metals is by their content, and one common division is into ferrous metals and non-ferrous metals. The term ferrous is derived from the Latin "Ferrum" which means "containing iron", thus ferrous metals contain iron and non ferrous metals do not. Ferrous metals may be pure iron, like wrought iron, or they may be alloys of iron and other elements. Steel, being an alloy of iron and carbon, would therefore be a ferrous metal.

Ferrous metals are often magnetic, but this property is not in and of itself sufficient to classify a metal as ferrous or non-ferrous. Austenitic stainless steel, a ferrous metal, is non-magnetic, while cobalt is magnetic but non-ferrous.

Common ferrous metals include the various irons and steels. Common non-ferrous metals include aluminum, tin, copper, zinc, and brass, an alloy of copper and zinc. Some precious metals such as silver, gold, and platinum are also non-ferrous.

Summary: Non-ferrous metals by definition do not contain iron while ferrous metals do. Ferrous metals are usually magnetic, although SOME non-ferrous metals are also magnetic.





I've yet to see EMT made out of the list in bold...
 
wbalsam1 said:
Would non-ferrous EMT also have to be bonded? Doesn't seem like it? :-? :smile:
Click to expand...

No

Non-ferrous EMT?

Do you have any? :cool:

Now I might run PVC and if they did not specify ferrous raceways I would have to bond my PVC...:grin:
 
iwire said:
No

Non-ferrous EMT?

Do you have any? :cool:

Now I might run PVC and if they did not specify ferrous raceways I would have to bond my PVC...:grin:
Click to expand...

Its mentioned in the code. See 358.10(B). I'm not sure I've ever seen any though. :-? As far as bondingPVC, I've actually seen painted PVC used as a "ground" for communications equipment....:grin:
 
wbalsam1 said:
Would non-ferrous EMT also have to be bonded? Doesn't seem like it? :-? :smile:
Click to expand...

That be refering to Eluminum Metalic Tubing? :wink: :grin:

Roger
 
stickboy1375 said:
Art. 250.64 (E) I think you bond the raceway to ensure the raceway and conductor are in parallel with each other...


1100205275_2.jpg
Click to expand...


In looking at this illustration, would a bonding locknut within the panel satisfy the NEC?
 
stickboy1375 said:
Code says both ends need to be bonded to the GEC...
Click to expand...

Yes it does, but it does not specify how that must be done.

At the panel end the conduit is bonded to the GEC by way of the panel steel.
 
iwire said:
Yes it does, but it does not specify how that must be done.

At the panel end the conduit is bonded to the GEC by way of the panel steel.
Click to expand...


This has always been my interpretation. The code isn't specific on how this is to be done. As Bob stated by virtue of the fact the the raceway is connected to the metal can can which is connected to the GEC isn't it really bonded at both ends?
 
I would agree, If I ever used a metal raceway for a EGC without first seeing the pictures of using a bonding busing on each end, I highly doubt I would have installed one inside of the cabinet...
 
250.64(E) Enclosures for Grounding Electrode Conductors

Ferrous metal enclosures for grounding electrode conductors shall be electrically continuous from the point of attachment to cabinets or equipment...

Ferrous metal enclosures that are not physically continuous from cabinets or equipment to the grounding electrode shall be made electrically continuous by bonding each end of the raceway or enclosure to the grounding electrode.



I also do not think that if the raceway enclosing the GEC is electrically continuous (installed with a locknut or other effective means) to the enclosure, that it would require the bonding requirements of this section, based on what I have highlighted from the NEC language.
 
roger said:
That be refering to Eluminum Metalic Tubing? :wink: :grin:

Roger
Click to expand...

I got some 1/2" emt from my supplier last week that I figured must have been either 90% aluminum, or some very thin, thinwall conduit. Hey, I can bend a 1/2" 90, but this stuff was kinking up on every bend. Maybe fresh from China using their high quality ferrous steel.
 
Status
Not open for further replies.
Top