Lock Nuts

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Dennis Alwon said:
Yes what the heck is that---:lol:

Why is a locknut not needed on the outside for RMC but it is required with the bushing
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As I read it, ignoring hubs, threadless, etc., if we are speaking of RGS (344.46) or IMC (342.46),
a bushing is required. Other than as required in some Classified Locations and on some > 250 volt to ground applications, UL (DWTT) allows termination with one locknut outside and one locknut & bushing inside, or simply one locknut outside and one metal bushing inside (sans inside locknut)

This was also discussed in a recent thread:

http://forums.mikeholt.com/showthread.php?t=156291&highlight=bushing
 
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Here is one made of metal with a insulated throat so it meets both code sections.

Specification Grade Insulated Bushings Catalog Page

For Threaded Rigid and IMC

Type B: 1?2? & 3?4? - Steel, Zinc Plated
1? to 6? - Malleable Iron, Zinc Plated

Type HB: 1?2? & 3?4? - Steel, Mechanical/Hot
Dip Galvanized
1? to 6? - Malleable Iron, Mechanical/Hot
Dip Galvanized

Type AB: Aluminum Bushing

Type RB: Bronze, for highly corrosive
atmospheres
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augie47 said:
In don't read it that way. Unless otherwise specified a metal bushing on the inside and a locknut on the outside of the enclosure is an acceptable means.
I discussed it with a UL rep and he is in agreement. To me, the wording on the referenced Appleton cut sheet can indicate a locknut on the outside and a metal bushing on the inside.
We my end up agreeing to disagree.
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iwire said:
I agree with that 100%.
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I agree also. This is/was the standard procedure for mud style boxes in poured concrete for 100 years.
 
augie47 said:
In don't read it that way. Unless otherwise specified a metal bushing on the inside and a locknut on the outside of the enclosure is an acceptable means.
I discussed it with a UL rep and he is in agreement. To me, the wording on the referenced Appleton cut sheet can indicate a locknut on the outside and a metal bushing on the inside.
We my end up agreeing to disagree.
Click to expand...

augie47 said:
As I read it, ignoring hubs, threadless, etc., if we are speaking of RGS (344.46) or IMC (342.46),
a bushing is required. Other than as required in some Classified Locations and on some > 250 volt to ground applications, UL (DWTT) allows termination with one locknut outside and one locknut & bushing inside, or simply one locknut outside and one metal bushing inside (sans inside locknut)

This was also discussed in a recent thread:

http://forums.mikeholt.com/showthread.php?t=156291&highlight=bushing
Click to expand...

iwire said:
I agree with that 100%.
Click to expand...

infinity said:
I agree also. This is/was the standard procedure for mud style boxes in poured concrete for 100 years.
Click to expand...

weressl said:
I second that motion.
Click to expand...

Okay, okay....I is wrong.:ashamed1:

Anybody have any salt for this crow I gotta eat.:cry:.....:D
 
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