Ohms law
Senior Member
- Location
- Sioux Falls,SD
Can you use bonding locknuts on reducing washers?
Bonding Locknuts
- Thread starter Ohms law
- Start date
- Status
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
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
- Location
- Logan, Utah
If you install the reducing washers correctly for bonding than a bonding locknut is not required.
Chris
Chris
Ohms law
Senior Member
- Location
- Sioux Falls,SD
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.
You might want to review this thread:
http://forums.mikeholt.com/showthread.php?t=147385&highlight=REDUCING+WASHER
http://forums.mikeholt.com/showthread.php?t=147385&highlight=REDUCING+WASHER
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
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
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?
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.
Ohms law
Senior Member
- Location
- Sioux Falls,SD
Explain what you mean correctly. Isn't this a no brainer?
A/A Fuel GTX
Senior Member
- Location
- WI & AZ
- Occupation
- Electrician
I thought that metallic, load side service conduits required bond bushings due to the fact that there is no OCPD in place?
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
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.
- Location
- Logan, Utah
Per the UL White Book,
Reducing washers can't be used for bonding on the line side of the service.
Chris
Reducing washers can't be used for bonding on the line side of the service.
Chris
- Location
- Logan, Utah
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
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
Period? or can be used with bonding bushings? I agree a bonding locknut would not be compliant with reducers.
- Location
- Logan, Utah
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
- Location
- Logan, Utah
If you use bonding bushings the reducing washers are not used for bonding just for a mechanical connection.
Chris
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
That was my assumption and wanted to make it clear.
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
- Status