Reducing Washers

[texie]

Are reducing washers listed or approved for grounding continuity? Do the 250 volt bonding rules affect this? For example, a 208Y/120 system where the conduit is used as the only EGC, do we have to bond around reducing washers? I'm not referring to service raceway, just circuits downstream of an OC device.

 

[iwire]

UL lists them for grounding but keep in mind 250.12 would require any paint be removed from the enclosure.

 

[texie]

UL lists them for grounding but keep in mind 250.12 would require any paint be removed from the enclosure.

I was thinking that this is true but I have not had a chance to verify the listing. I have a situation where someone above me cited this as a violation on a job and I came along and said it is not a violation (120 volt to ground). I have always thought that at this voltage reducing washers were OK for this but now I'm being challenged. As far as I recall the NEC does not specifically mention reducing washers.

 

[Gregg Harris]

I was thinking that this is true but I have not had a chance to verify the listing. I have a situation where someone above me cited this as a violation on a job and I came along and said it is not a violation (120 volt to ground). I have always thought that at this voltage reducing washers were OK for this but now I'm being challenged. As far as I recall the NEC does not specifically mention reducing washers.

Take a look at the listing in UL under QCRV

suitable if all knockouts are removed

 

[iwire]

I have a situation where someone above me cited this as a violation on a job and I came along and said it is not a violation (120 volt to ground). I have always thought that at this voltage reducing washers were OK for this but now I'm being challenged.

Reducing washers are listed for grounding up to at least 600 volts, maybe beyond

Technically you can avoid bonding bushings for concentric KOs over 250 volts to ground if you break out all the concentrics and use reducing washers. I am not saying it is as good, just code compliant.