Splice in a "C" Type Condulet

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wirestu

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We are installing a long run of 3" RSC in a Class 1 Division 1 location. We plan on pulling 3-250 MCM conductors through the conduit. There are many zigs and zags through the conduit run, which we handled by installing explosion proof LB after every 3 90 degree bends. Since the length of the cable is approximately 1500' we would like to install a splice in the cable in the classified area. Since the cost of an explosion proof junction box to meet wire bending requirements will present a time and financial burden, our thought is to use a 4" explosion proof "C" condulet with 4" to 3" explosion proof reducer bushings and use compression sleeves to splice the 250 MCM cables in the condulet. Does the NEC allow this? If this is allowed, are we required to place seal fitting at the condulet since the condulet is acting as a junction box and the conduit is larger than 2".

Thanks in advance,

Stu
 
Re: Splice in a "C" Type Condulet

314.16(C) says that you can splice if the conduit body is listed with its cubic inch capacity, so if that is the case you can.

501.5(A)(1) says that you must seal within 18" because your pipe is greater than 2".
 
Re: Splice in a "C" Type Condulet

Stu,
I doubt that there is enough room, even using an oversized C to physically make that splice.
Don
 
Re: Splice in a "C" Type Condulet

Ryan and Don have both made good comments. I'm curious about any installation that requires 1500' of 3" conduit in a Division 1 location. Would you mind telling us more about it?
 
Re: Splice in a "C" Type Condulet

I was curious about that as well. Seems like in such a long run you ought to be able to find an unclassified place to put in a splice box.
 
Re: Splice in a "C" Type Condulet

I was more curious about what would cause such a large Div I location in the first place. My general experience is that this is over-kill.
 
Re: Splice in a "C" Type Condulet

Originally posted by rbalex:
I was more curious about what would cause such a large Div I location in the first place. My general experience is that this is over-kill.
Click to expand...
Yea. Most of my experience with Div I locations are very small areas. I can't imagine a conduit run that stretches for 1500' without passing through a lot of unclassified areas along the way. Plus 1500' is a VERY long way to run conduit in the first place. Even so, I doubt the cost of an XP jbox here and there would add much cost to such a run anyway.

[ October 29, 2004, 07:16 PM: Message edited by: petersonra ]
 
Re: Splice in a "C" Type Condulet

The wiring is for an explosion proof pump at the base of a gasoline storage pump. The tank area has an impermeable liner and the only penetrations allowed are for the product pipeline supports. We are mounting our conduits on structural steel mounted of these product pipeline support system. The pipeline runs in the contained area below the height of the dyke near the tanks. We are trying to use the "C" condulet because it is readily available and there are other conduits run next to our 3" conduit so install a junction box would be difficult.

Thanks,

Stu
 
Re: Splice in a "C" Type Condulet

I agree with the posters that the design needs to account for the splicing. Splicing conductors of that size in a condulet is not such a great idea, if it is even permitted.

Pierre
 
Re: Splice in a "C" Type Condulet

Stu,

I've reviewed your description. I assume you meant, "The wiring is for an explosion proof pump at the base of a gasoline storage tank .

At the face value of your description, I'd say you are actually in a Division 2 location if this is an outdoor installation (even indoors if there is adequate ventilation).

If you have a copy of NFPA 497 available it sounds similar to a Figure 3-8.19 application. (See the left-hand side). API RP 500 has a similar figure where both sides have dikes.

Figure%203-8.19.jpg



See also Drainage ditches, separators, impounding basins in Table 515.3.
 
Re: Splice in a "C" Type Condulet

Thanks for the replies. I agree that it is a Class 1 Division 2 location but our customer wants all wiring to meet Class 1 Division 1 requirements. I have been unable to find a "C" condulet anyway. Does anybody have any other ideas that would allow us to splice and meet our customers requirements.

Thanks,

Stu
 
Re: Splice in a "C" Type Condulet

Personally, I think you've been painted into a corner. If you can't convince your client to properly classify the area and install per that classification, you?re left with no real economically ($ and time) viable solution.

The best you can do with what you have is avoid splicing. Get rid of the ?L?s and replace them with factory bends, if possible. Use intermediate pulling sleeves, such as Crouse-Hinds type ESC. Do some very careful pulling calcs; pulling sleeves usually increase the pulling tension but reduce potential conductor damage at turns because the conductor-bending radius is greater than with ?L?s. Designed and executed in the field properly, you pull from one sleeve and out the next. A gentle transition back into the raceway system can be created for the next pull. It still isn?t easy, but it can be done. I?ve used this method in Division 2, but the ESC fittings are also listed for Division 1.
 
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