Bonding Locknuts

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I believe most reducing washers are suitable for bonding. If that is the case then yes you can AFAIK. This is from the UL Book

Metal reducing washers are considered suitable for grounding for use in circuits over and under 250 V and where installed in accordance with
ANSI/NFPA 70, ‘‘National Electrical Code.’’ Reducing washers are intended for use with metal enclosures having a minimum thickness of 0.053 in. for non-service conductors only. Reducing washers may be installed in enclosures provided with concentric or eccentric knockouts, only after all of the concentric and eccentric rings have been removed. However, those enclosures containing concentric and eccentric knockouts that have been Listed for bonding purposes may be used with reducing washers without all knockouts being removed
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Ohms law said:
Can I use a bonding locknut on a service ran in EMT from the meter socket to panel? Bonding locknut is in meter socket side.
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You can but it is not neccessary. A better way to do this (from meter socket to another enclosure) is with PVC, that way you have done away with the parallel neutral path.

Roger
 
I am confused now.. It seems we are saying that a service metal raceway does not need special bonding to panels via grounding locknuts or grounding bushings. Is this correct?
 
Dennis Alwon said:
I am confused now.. It seems we are saying that a service metal raceway does not need special bonding to panels via grounding locknuts or grounding bushings. Is this correct?
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As I read it, metallic service conduits must be bonded by one of the methods shown in 250.92.
I've always felt reducing washers would impair such a connection, but, apparently, if installed per listing, with the use of a grounding locknut, they are acceptable.
 
roger said:
You can but it is not neccessary. A better way to do this (from meter socket to another enclosure) is with PVC, that way you have done away with the parallel neutral path.

Roger
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I thought that metallic, load side service conduits required bond bushings due to the fact that there is no OCPD in place?
 
augie47 said:
As I read it, metallic service conduits must be bonded by one of the methods shown in 250.92.
I've always felt reducing washers would impair such a connection, but, apparently, if installed per listing, with the use of a grounding locknut, they are acceptable.
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Okay that was my take but Roger's statement that a bonding locknut was not needed seemed to imply that no other bonding other than a standard locknut was required.
 
Dennis Alwon said:
Okay that was my take but Roger's statement that a bonding locknut was not needed seemed to imply that no other bonding other than a standard locknut was required.
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Roger's statement was to use PVC conduit between the meter and the service disconnecting means and by doing that bonding locknuts are not needed as the PVC does not require bonding.

Chris
 
Ohms law said:
Explain what you mean correctly. Isn't this a no brainer?
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You would think.

What I meant by "Correctly" is that by the listing requirements ALL concentric and eccentric rings must be removed for the washers to be used for bonding unless the concentric or eccentric knockouts must be listed for bonding without their removal. Many times installers use reducing washers without removing all of the concentric and eccentric rings.

Chris
 
roger said:
You can but it is not neccessary. A better way to do this (from meter socket to another enclosure) is with PVC, that way you have done away with the parallel neutral path.

Roger
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Dennis Alwon said:
I am confused now.. It seems we are saying that a service metal raceway does not need special bonding to panels via grounding locknuts or grounding bushings. Is this correct?
Click to expand...

raider1 said:
Roger's statement was to use PVC conduit between the meter and the service disconnecting means and by doing that bonding locknuts are not needed as the PVC does not require bonding.

Chris
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Dennis, Chris is correct, I was meaning PVC would negate the need to bond the metallic raceway. I agree that 250.92(B) requires special attention to bonding of metal raceways at service equipment.

Roger
 
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