one hole strap vs. mini-clip?

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rgibbs4

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I was told not to use one hole straps for supporting exterior EMT. I was told it holds moisture which causes the pipe to rust. The person told me to use mini-clips or straps. he said that it is a new code in the NEC codebook. I can't find it in the code book. Is what he telling me true?
 

celtic

Senior Member
Location
NJ
Re: one hole strap vs. mini-clip?

By mini-clip, do you mean a minerallac or a "cowboy"?



How does this not retain water as opposed to a standard one-hole strap? They are both outdoors exposed to the elements ?

I think thus guy is pulling your leg...tell him you need a bucket of steam; a set-screw seal-tight coupling; or an ID-ten-T.


[EDIT: Below]
You can view the NEC 2005 on line for free...check the links in this thread:
Free Access to the 2005 NEC

[ August 08, 2005, 12:20 AM: Message edited by: celtic ]
 

iwire

Moderator
Staff member
Location
Massachusetts
Re: one hole strap vs. mini-clip?

Originally posted by celtic:
By mini-clip, do you mean a minerallac or a "cowboy"?

:p

Originally posted by celtic:
How does this not retain water as opposed to a standard one-hole strap? They are both outdoors exposed to the elements ?
Yeah both clips are exposed to moisture, however the 'cowboys' hold the pipe itself away from the surface. With the pipe held away from the surface water is not trapped between the surface and the pipe.

This really does make the pipe last longer.

This is the same reason for 312.2 which requires a 1/4" air space behind enclosures mounted in damp or wet locations.

Often on our jobs the specs will require all raceways installed in wet locations to have an air space behind them.

You can still use a 1 hole strap but you order them with back spacers which install under the strap and hold the pipe off the surface.

rgibbs4 I do not believe it is in the NEC, this person may know something about job specifications.

Regardless of the NEC or job specs it is a good practice to space raceways off the surface. :cool:
 

jim dungar

Moderator
Staff member
Location
Wisconsin
Occupation
Retired Electrical Engineer - Power Systems
Re: one hole strap vs. mini-clip?

There is nothing wrong with using one-hole straps as long as the conduit is spaced away from the wall. Many maufacturers have spacers specifically for use with one-hole straps.
 

OneWay

Member
Location
Texas
Re: one hole strap vs. mini-clip?

Originally posted by iwire:
Originally posted by celtic:
By mini-clip, do you mean a minerallac or a "cowboy"?

:p

Originally posted by celtic:
How does this not retain water as opposed to a standard one-hole strap? They are both outdoors exposed to the elements ?
Yeah both clips are exposed to moisture, however the 'cowboys' hold the pipe itself away from the surface. With the pipe held away from the surface water is not trapped between the surface and the pipe.

This really does make the pipe last longer.

This is the same reason for 312.2 which requires a 1/4" air space behind enclosures mounted in damp or wet locations.

Often on our jobs the specs will require all raceways installed in wet locations to have an air space behind them.

You can still use a 1 hole strap but you order them with back spacers which install under the strap and hold the pipe off the surface.

rgibbs4 I do not believe it is in the NEC, this person may know something about job specifications.

Regardless of the NEC or job specs it is a good practice to space raceways off the surface. :cool:
Good suggestion Bob to maintain the integrity of the conduit system is impairitive to the overall integrity of the circuits it is housing and is always a good idea to consider moisture in damp and wet locations when making a selection on which support application you intend on installing on any surface(especially exterior surface raceways).

[ August 12, 2005, 09:53 AM: Message edited by: OneWay ]
 

celtic

Senior Member
Location
NJ
Re: one hole strap vs. mini-clip?

While I agree in "theory" with keeping conduit off exposed surfaces, the reality is (at least in my neck of the planet) that the fastener quits long before the pipe system.
 

iwire

Moderator
Staff member
Location
Massachusetts
Re: one hole strap vs. mini-clip?

Originally posted by celtic:
While I agree in "theory" with keeping conduit off exposed surfaces, the reality is (at least in my neck of the planet) that the fastener quits long before the pipe system.
Get a better grade of fasteners, I am not being a wise guy I am being serious.

Most of us use stamped steel clips or minnis and inside these are fine.

In wet locations for a long lasting fastener use a malleable steel one hole clip with a back spacer.

[ August 12, 2005, 08:07 AM: Message edited by: iwire ]
 

celtic

Senior Member
Location
NJ
Re: one hole strap vs. mini-clip?

Originally posted by iwire:
...I am not being a wise guy...

You calling me "old", wise guy? :D

What I mean to illustrate is that the pipe work I see hanging on for dear life has been in place for at least 30 - 40 years...some of them held in "place" by the screw and wood dowel method. The pipe, while showing some discoloration, does not appear to be compromised.
 
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