# bonding bushings



## karl_r (Nov 5, 2012)

It is my understanding that any EMT entering a PVC junction box require bonding bushing and all bushings must be bonded together. If I run a ground with my EMT, why do I need the bushing?

I only have a pvc box somewhere in the middle of my EMT run because it must be WP. I'd say that my system is always grounded anyway...


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## McClary’s Electrical (Feb 21, 2009)

karl_r said:


> It is my understanding that any EMT entering a PVC junction box require bonding bushing and all bushings must be bonded together. If I run a ground with my EMT, why do I need the bushing?
> 
> I only have a pvc box somewhere in the middle of my EMT run because it must be WP. I'd say that my system is always grounded anyway...


You are wrong to say any emt entering a box need bonding, but if that emt contains service entrance conductors, you need to bond both ends.


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## macmikeman (Jan 23, 2007)

mcclary's electrical said:


> You are wrong to say any emt entering a box need bonding, but if that emt contains service entrance conductors, you need to bond both ends.


 250.4 (A) (3) BONDING OF ELECTRICAL EQUIPMENT. Normally non current carrying conductive materials enclosing electrical conductors or equipment, or forming part of such equipment , shall be connected together and to the electrical supply source in a manner that establishes an effective ground fault current path. 

It's Saturday night, your swing.


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## McClary’s Electrical (Feb 21, 2009)

macmikeman said:


> 250.4 (A) (3) BONDING OF ELECTRICAL EQUIPMENT. Normally non current carrying conductive materials enclosing electrical conductors or equipment, or forming part of such equipment , shall be connected together and to the electrical supply source in a manner that establishes an effective ground fault current path.
> 
> It's Saturday night, your swing.


My wording was wrong. I meant he was incorrect to say it needed bonding on both ends. 

It only needs that if it contains a gec


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## 51360 (Jun 9, 2014)

karl_r said:


> It is my understanding that any EMT entering a PVC junction box require bonding bushing and all bushings must be bonded together. If I run a ground with my EMT, why do I need the bushing?
> 
> I only have a pvc box somewhere in the middle of my EMT run because it must be WP. I'd say that my system is always grounded anyway...


Section 10 in the *CEC* rules

There are other options in your case, (10-610 ), that satisfy code.

10-606 regarding service equipment is similar.

10-906 deals with PVC boxes.

My interpretation is that you are ok with a bonding wire ran in the conduit, as long as you maintain continuity of the conduit and allow enough length to bond any device mounted on the PVC box.

So yes, you may have to use bushings, and connect them to the bonding conductor. Not a big deal. 

Borgi


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## 51360 (Jun 9, 2014)

karl_r said:


> It is my understanding that any EMT entering a PVC junction box require bonding bushing and all bushings must be bonded together. *If I run a ground with my EMT, why do I need the bushing?*
> 
> I only have a pvc box somewhere in the middle of my EMT run because it must be WP. I'd say that my system is always grounded anyway...


The EMT must be bonded. A seperate bonding wire ran in the conduit doesn't accomplish that unless bushings are used.

Hope I'm saying that correctly! 

No word of a lie, I have seen PVC conduit with metal bushings on them and connected to the metal enclosure. Nothing wrong with it, but not needed.

Borgi


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## karl_r (Nov 5, 2012)

thanks for your help guys


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## 99cents (Aug 20, 2012)

I always forget the rules so, when in doubt, I bond.


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## B-Nabs (Jun 4, 2014)

Would it not be true, though, that if the EMT comes from a metal box before the PVC one, and continues to another metal box after, and the bond wire in the pipes is connected to those two metal boxes and spliced continuously throughout, then the EMT would be bonded by virtue of its connection to the bonded metal boxes, and bonding bushings in the PVC box would not be necessary?


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## 51360 (Jun 9, 2014)

B-Nabs said:


> Would it not be true, though, that if the EMT comes from a metal box before the PVC one, and continues to another metal box after, and the bond wire in the pipes is connected to those two metal boxes and spliced continuously throughout, then the EMT would be bonded by virtue of its connection to the bonded metal boxes, and bonding bushings in the PVC box would not be necessary?


Yes, in that case you would be ok I think. I just seen that the ordinal poster did say that. ( I missed that ). 

Just as easy, and good practice, to use the bushings at the PVC box. I always anticipate something being removed.

Borgi


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## karl_r (Nov 5, 2012)

Borgi said:


> Yes, in that case you would be ok I think. I just seen that the ordinal poster did say that. ( I missed that ).
> 
> Just as easy, and good practice, to use the bushings at the PVC box. I always anticipate something being removed.
> 
> Borgi


that was my point too. Why the inspector would fail me if the system is continuous anyway?


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## McClary’s Electrical (Feb 21, 2009)

B-Nabs said:


> Would it not be true, though, that if the EMT comes from a metal box before the PVC one, and continues to another metal box after, and the bond wire in the pipes is connected to those two metal boxes and spliced continuously throughout, then the EMT would be bonded by virtue of its connection to the bonded metal boxes, and bonding bushings in the PVC box would not be necessary?










Borgi said:


> Yes, in that case you would be ok I think. I just seen that the ordinal poster did say that. ( I missed that ).
> 
> Just as easy, and good practice, to use the bushings at the PVC box. I always anticipate something being removed.
> 
> Borgi










karl_r said:


> that was my point too. Why the inspector would fail me if the system is continuous anyway?


If it's service entrance, you'd need bonding bushing on the conduit


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## 51360 (Jun 9, 2014)

mcclary's electrical said:


> If it's service entrance, you'd need bonding bushing on the conduit


CEC is different from the NEC in some respects regarding bonding the service entrance conduit.

Are you able to post the article from the NEC in that respect. 

Borgi


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## Cow (Jan 16, 2008)

You would only need to bond the emt if it was isolated between pvc boxes. If you left a metal enclosure that was bonded(j-box, loadcenter, etc), you are bonded where the conduit originates. Or vise versa, if you're running to a bonded metal enclosure, same story.

You need to think in terms of fault current paths. If a wire faulted to ground in an isolated metal conduit, how would the breaker trip? Now you have an energized conduit.


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## 51360 (Jun 9, 2014)

karl_r said:


> that was my point too. *Why the inspector would fail me* if the system is continuous anyway?


That surprises me as I think you are correct.

Maybe he/she doesn't like you, or was having a bad day!

Damned inspectors. 

Borgi


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## shocksystems (Apr 25, 2009)

I think the bonding bushing is required per this article:

NEC 314.3 
"Nonmetallic Boxes. Nonmetallic boxes shall be permitted only with open wiring on insulators, concealed knob-and-tube wiring, cabled wiring methods with entirely nonmetallic sheaths, flexible cords, and nonmetallic raceways.

Exception No. 1: Where internal bonding means are provided between all entries, nonmetallic boxes shall be permitted to be used with metal raceways or metal-armored cables."


Cheers!

Jim


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