# Reducing washers on services



## manchestersparky (Mar 25, 2007)

Question:
Are metal reducing washers permitted for use with metal enclosures containing service conductors.

Why or Why Not....


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## cdnelectrician (Mar 14, 2008)

I have had to use them on occasion especially on cutler hammer panels and some brands of meter cans. DAMN concentric KO's never seem come out properly! If I have to use them on the bottom of a meter can I spray them with grey rust paint to prevent them from rusting. Keep in mind most service raceways here are PVC. I know it looks like crap, but sometimes those KO's just will not come out properly no matter what you do. Especially on cutler hammer panels.


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## manchestersparky (Mar 25, 2007)

Yes they do get used,but are they PERMITTED to be used


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## 480sparky (Sep 20, 2007)

cdnelectrician said:


> ...but sometimes those KO's just will not come out properly no matter what you do. Especially .......


Use your KO set.


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## cdnelectrician (Mar 14, 2008)

I was referring to the 1 1/4 KO which is the first KO in the ring and the one most commonly used for 100 amp services...usually the 1 1/2 KO comes out at the same time on cheaper meter cans and panels. If I tried to drill a hole for my KO punch it will just tear the whole thing to bits. I do use my KO punch for anything above 1 1/2 it works! Sorry off topic! As far as I know reducing washers are allowed here, although frowned on by the inspector for new installs.


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## seo (Oct 28, 2008)

Reducing washers are intended for use with metal enclosures having a minimum thickness of 0.053 in. for non-service conductors only. Per UL White Book. Hope this answers your question.


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## manchestersparky (Mar 25, 2007)

Thats correct!
I was curious how many others knew this little fact.

I'll have to come up with another one that is a little more of a challenge


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## 480sparky (Sep 20, 2007)

manchestersparky said:


> Thats correct!
> I was curious how many others knew this little fact.
> 
> I'll have to come up with another one that is a little more of a challenge


Try "What color is the green ground screw?" :laughing:


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## electricista (Jan 11, 2009)

manchestersparky said:


> Thats correct!
> I was curious how many others knew this little fact.
> 
> I'll have to come up with another one that is a little more of a challenge


I did not know this fact. I cannot understand it either. If I have a hole that is too large are you saying I cannot use reducing if their are service conductors in the conduit. Suppose it is PVC conduit. What is this all about? 

If I have metal conduit wouldn't a bonding bushing deal with this? Why only on service conductors and not feeders? :icon_confused:


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## seo (Oct 28, 2008)

You would have to run these scenarios by your local AHJ. PVC might not be as much of an issue . Per UL they are not listed for service conductors and are for feeders, possibly because of the available fault current at the service.


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