UL Listed Reducing Washers

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tom baker

tom baker

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UL has a listing for reducing washers, they are stamped with a UL. This type of reducing washer does not require a bonding jumper to maintain the effective ground fault current path.
Has anyone ever seen a UL listed reducing washer and if so who is the manufacturer?
 
Interesting. None of the RWs I have are listed and I checked with T&B and they don't make them as there is no demand.
Sounds like a visit to the wholesale house is in order.
 
tom baker said:
UL has a listing for reducing washers, they are stamped with a UL. This type of reducing washer does not require a bonding jumper to maintain the effective ground fault current path.
Has anyone ever seen a UL listed reducing washer and if so who is the manufacturer?
Click to expand...


Are you sure about this statement?
The UL White Book, (QCRV) gives direction as to the installation method for whether or not bonding around the reducing washers would or would not be necessary.
Under the Grounding portion of (QCRV)
 
Pierre C Belarge said:
Are you sure about this statement?
The UL White Book, (QCRV) gives direction as to the installation method for whether or not bonding around the reducing washers would or would not be necessary.
Under the Grounding portion of (QCRV)
Click to expand...

As hard as it to believe the UL white book clearly states reducing washers are suitable for grounding.

2007 White Book OUTLET BUSHINGS AND FITTINGS (QCRV)

GROUNDING

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.
Click to expand...
 
iwire said:
As hard as it to believe the UL white book clearly states reducing washers are suitable for grounding.
Click to expand...

This provides us with an economic way around using bond bushings. :wink: :D

Roger
 
Pierre C Belarge said:
I agree that they are permitted for use within the effective ground fault current path. Just that there are some parameters to follow, it is not a permitted method for all installations.
Click to expand...

There are no more 'parameters to follow' with UL listed reducing washers then there are for UL listed EMT connectors. Both are suitable grounding means. If an EMT connector is suitable for grounding under a set of conditions so is a reducing washer.

Your on shaky ground if you fail it for the reducing washer.

But I bet you could nail them with 250.12, I have never seen anyone clean the paint off under the reducing washers. :)
 
iwire said:
But I bet you could nail them with 250.12, I have never seen anyone clean the paint off under the reducing washers. :)
Click to expand...

I always did. :wink: :D

Roger
 
roger said:
I always did. :wink: :D

Roger
Click to expand...

Yeah, me too............ :wink:

Well maybe not when I use them with NM connectors. :grin:

I will be thinking of it next time I run a raceway, generally I avoid oversize KOs and make new one the right size when that is possible.
 
iwire said:
There are no more 'parameters to follow' with UL listed reducing washers then there are for UL listed EMT connectors. Both are suitable grounding means. If an EMT connector is suitable for grounding under a set of conditions so is a reducing washer.

Your on shaky ground if you fail it for the reducing washer.

But I bet you could nail them with 250.12, I have never seen anyone clean the paint off under the reducing washers. :)
Click to expand...


If this is directed at me, I am not sure why you seem to always think that when I make a comment, that I am failing some installation. If that was so, the work in southern Westchester County would have come to a halt about 5 years ago. :wink:


If one is to read my comments, I agree with what has been posted here. I never mentioned any other type of connectors, my comments have been restricted to reducing washers.


OUTLET BUSHINGS AND FITTINGS (QCRV)

GROUNDING​
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.


These are the "parameter" I was alluding to. Remember that many boxes manufactured prior to about 7-9 years ago were not listed for bonding purposes. If one should be working in older installations (not uncommon), one has to be careful with the use of reducing washers as part of the "effective ground fault current path"
 
Sorry about that small print, I did not review my entry before posting.


Here is a picture I found showing what I was trying to explain. It is an older box, of which I am not sure if it is/was listed as suitable for bonding purposes. As can be seen, not all of the KOs have been removed. I am not saying this is or is not permitted, I am trying to show what is meant by the UL White Book (QCRV)
ReducingWasher.jpg
 
You lost me Pierre, I am not following you.

Why would I assume you would fail it? :grin:

Because your an inspector and your posts in this thread seem to indicate you do not believe the washers are suitable for grounding.

From Tom B

This type of reducing washer does not require a bonding jumper to maintain the effective ground fault current path.
Click to expand...

Your response

Are you sure about this statement?
Click to expand...
 
You should read post #9, it might help you relieve yourself of some anxiety you may have of my inspections so you can sleep better tonight. :wink: :D



I am not sure if your first line in the last post was serious, but I will take it as so and elaborate just a little as to my posts here in this thread.




OUTLET BUSHINGS AND FITTINGS (QCRV)


GROUNDING​

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.


These are the "parameter" I was alluding to. Remember that many boxes manufactured prior to about 7-9 years ago were not listed for bonding purposes. If one should be working in older installations (not uncommon), one has to be careful with the use of reducing washers as part of the "effective ground fault current path"





This does not mean I am going to violate all of the installations I see, just some of them. ;)
 
"Because your an inspector and your posts in this thread seem to indicate you do not believe the washers are suitable for grounding.

From Tom B

Quote:
This type of reducing washer does not require a bonding jumper to maintain the effective ground fault current path.


Your response

Quote:
Are you sure about this statement?"




From reading in the UL White Book, it is fair to say that Tom's "blanket statement" is too general in nature... that is what prompted my response.
 
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