A Little Help Please

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wbalsam1

wbalsam1

Senior Member
Location
Upper Jay, NY
In Class 1 locations, all conduit must be rigid metal or steel IMC with at least 5 full tapered threads tightly engaged in the enclosure. A new exception to 500.8(D) allows 4 1/2 for factory threaded NPT entries. When field drilling and tapping is performed it may be required to drill & tap deeper than standard NPT to insure engagement of 5 full threads.

No matter how good and thorough the pipe thread is engaged, alternate changes in temperature and barometric pressure cause the conduit(s) to "breathe". The moisture in this circulating air condenses and collects at the base of vertical conduit runs and in equipment enclosures. This is where inspection fittings should be utilized and equipped with xp drains to automatically drain off the water. :)
 
H

HighWirey

Senior Member
Location
Cocoa, Florida, USA
fishin' electrician said:
The Crouse-Hinds RE reducers are stamped CLI-CLII-CLIII on the small lip that protrudes from the box and have tapered threads. There are at least 7 threads on these fittings.

Judging from the amount of the bushing inside the box and that the lip is still visible outside the box, I'd say there is a good chance these are correct. Only your inspector can look for the stamp.

I am curious as to how all this was spun together without seeing any unions and with two entries on the same side of the box.
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You beat me to the punch. I always used Crouse-Hinds reducing bushings because they are clearly stamped with the Class and Div. Yes, I agree that those REs are straight threaded. But then we are supposed to know about that 7 thread rule.

As for the taper, I never cared, nor did my inspectors care about the taper, so long as the REs were clearly stamped for the location and installed properly.

As for the number of taps (we in the trade used to call 'em hubs) in a fitting, no one cared, as long as the extraneous hubs were sealed with a properly identified and installed closure plug. Those plugs with ID are also a Crouse item. Some of the posters here seem to know how to spot a proper RE from it's 'rim'. I was never that smart, always gave the inspector a few in his hand prior to install (except for those 4-3s). He put 'em on his desk for show and tell later. He was a happy camper from then on.

Again, as for the number of hubs in a fitting, you cannot appreciate extra hubs until you have been in the trench. You can plan, plan and plan, you will still need another hub . . .

As to how the origional pictured conduits were 'spun' together, I cannot tell. Those conduits may have disappeared under the ground. A lot of very legal, but not so good looking stuff can and should be buried in the ground.

As for both origional pictures, eveything looks good. I personally don't like sealoffs installed so close to the box. Makes them difficult to pour, and difficult for the inspector to verify those REs IDs if need be. But that is only an aesthetic thing.

Rhetorical question here: how do you guys spell Bluegrass, West Virginia?

Advice here is let that poor contractor off the hook. But then my name is not on your signoff sheet . . .
 
Pierre C Belarge

Pierre C Belarge

Senior Member
Location
Westchester County, New York
I did not say the contractor had problems from me, I merely was looking for clarification on the material.
You see, whenever I did this kind of work, we used 1900 boxes and regular round boxes covered in duct seal...:wink: :grin:

So now I have to get use to this new found good stuff. :cool: :wink:
 
K

KentAT

Senior Member
Location
Northeastern PA
I have also been questioned about my use of reducer bushings in my hazardous installations.

The inspectors are concerned with:

1. Reducers between the seal and an enclosure or jb. I point to the last text of 501.15(A)(1) where they are specifically allowed. I also usually have to produce the Crouse-Hinds catalog page showing the REs I use. (They have tapered threads).

2. Reducers between a seal and a Div 1 boundary. I point them to 501.15(A)(4), and the text that reads "...Except for listed explosionproof reducers at the conduit seal, there shall be no union, coupling, box, or fitting between the conduit seal and the point at which the conduit leaves the Division 1 location."

We usually end up discussing the second one more. The only thing I can think of as to why the boundary reducer is allowed has to do with the 25% conduit fill limit for seals in a hazardous location. If you couldn't use a listed explosionproof reducer, then you couldn't install a larger trade size seal to allow you to fill your conduit to 40% for 3 or more conductors (before the introduction of expanded-fill seal fittings).
 
don_resqcapt19

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
Pierre,
Is the box listed for classified areas? It does not look like the female hubs are long enough for 5 full threads. Or are the seals boundary seals and the box and reducing bushing not in the classified area?
 
Pierre C Belarge

Pierre C Belarge

Senior Member
Location
Westchester County, New York
don_resqcapt19 said:
Pierre,
Is the box listed for classified areas? It does not look like the female hubs are long enough for 5 full threads. Or are the seals boundary seals and the box and reducing bushing not in the classified area?
Click to expand...


Hello Don
I know as much about this work site and boxes as anyone who has seen the pictures.
I was viewing the pictures one of our guys took, when I saw the reducers...that peaked my interest.
I will try to find out more tomorrow.
 
don_resqcapt19

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
Smart,
Thanks...all of the Crouse EP conduit bodies that I have used have a much longer hub. I have not installed those boxes and didn't know that they are made different.
 
jrannis

jrannis

Senior Member
Location
Fort Lauderdale/ Miami
Pierre C Belarge said:
One of the inspectors that work for us took this picture. I was wondering if this would be a permitted installation for a Classified location.


The first picture is of an XP box
etsny002.jpg







The second picture shows the box has reducers in it. Is this permitted for this location??
etsny004.jpg
Click to expand...

Looks to me like you have one vertical seal-off and one horizontal seal-off. Unless the one on the left can be used either way.
Is this box in a classed area? Just a splice, no device? Two seal-offs?
 
C

coulter

Senior Member
ptonsparky said:
While you are looking, see if that is pipe dope of some sort on the threads of the nipples etc. That is not allowed, even if the fittings are rated for the area. Silicone to keep rain out goes on after the nipples are made up to the box, not on the threads prior to.
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Tom -
Why is this? I don't recall any regulation or installation directions that would prevent putting pipe dope on say underground conduit threads. But this would only be the second one I have wrong on this subject:-?

AFAIK conduit threads, with pipe dope, wrench tight, are electrically connected.

carl
 
e57

e57

Senior Member
Location
San Francisco, CA
I too dont do any XP work - but ? is.... Are the box plugs tapered?? And from what I understand is that the idea of threaded fittings is to reduce the temp of exploding gasses entering or exiting the threads - if the box has sealing fittings on both entering and exiting conduits - why does the box matter? Depending on the actual location of the box, and whats in it - right?

e.g. 501.4B4 commentary
In Class I, Division 2 locations, boxes, fittings, and joints are not required to be explosionproof at lighting outlets or at enclosures containing no arcing devices, such as solenoids and control transformers, if the maximum operating temperature of any exposed surface does not exceed 80 percent of the ignition temperature in degrees Celsius. Where general-purpose enclosures are permitted by 501.4(B)(4), rigid or intermediate metal conduit may be used with locknuts and bushings. However, a bonding jumper with proper fittings or bonding-type locknuts is required to be used between the enclosure and the raceway to ensure adequate bonding from the hazardous area to the point of grounding at the service equipment or separately derived system. See 501.16(A) for grounding and bonding requirements.
Click to expand...
 
Last edited:
R

rkoop

Member
a little help please

a little help please

All the fittings in the picture appear to be ul listed electrical parts. I see no violation of code. to my knowledge there is no hazardous location reducers available because you may use ul listed reducers.. If using GRC conduit then GRC approved reducers may be used. I would keep the junction box above ground and accessable of course. Rodney
 
don_resqcapt19

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
rkoop said:
to my knowledge there is no hazardous location reducers available because you may use ul listed reducers..
Click to expand...
Rodney,
I use Crouse and Appleton reducing bushings that are marked for Class I, Divison 1 almost every day. I know that Appleton has other reducing bushings that are not so marked.
 
cschmid

cschmid

Senior Member
Location
Northern cold country
So I am curious as I have never seen reducers in a classified box..So do we have a clear cut consensious here whether this is okay or not..I have not read all the quoted codes but do not see what type of classification area it is..or does it even make a difference..
 
R

rkoop

Member
a little help please

a little help please

Don: I would concur with you. If hazardous location fittings are available then that would be the way to go. Rodney
 
don_resqcapt19

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
cschmid said:
So I am curious as I have never seen reducers in a classified box..So do we have a clear cut consensious here whether this is okay or not..I have not read all the quoted codes but do not see what type of classification area it is..or does it even make a difference..
Click to expand...
I think it is very clear that the reducing bushing is permitted between the box and the seal per the last part of 501.15(A)(1). (2005 NEC).
 
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