Adding conduit holes on side of Switchgear in the field

[power2engineer]

What is the acceptable Electrical installation practice for Medium voltage 13.8 KV Switch enclosure feeder cables conduit entering from the Side of the enclosure instead of bottom.

Please see attached Photo. The contractor installed the UG conduits for 13.8 KV Feeder about 18 Inches outside the enclosure perimeter so the manufacturer provided floor cutout cannot be used. We want to run 2 LBs and enter the enclosure from the side of the enclosure just above floor. The installation is blocked from people walking freeling around it. Is this installation in violation of any NEC code?

 

[waross]

I suggest using sealing hubs to enter the enclosure.These are known in the trade as Meyers Hubs or Bullet Hubs.
They will provide a rain-tight conduit entry.
It goes without saying that all the hardware must be rain-tight.
You may need to provide mechanical protection around the conduits and LBs.
Rigid conduit (either steel or PVC) is often accepted as inherently self protecting, but there are exceptions.
Conduits in or near vehicular areas may need extra protection even for rigid steel conduits.

Bottom line;
Rain-tight and suitably mechanically protected.

Note the "O" ring to seal against the enclosure.
This is a standard feature of Meyers Hubs.
They are available in:
Die Cast, (Zinc)
Aluminum
Steel
Malleable Iron
Stainless Steel. (Shown)

--------------------
Ohm's law
Not just a good idea;
It's the LAW!

 

[MKFPE]

Can you meet the cable minimum bending radius specification using LBs? As I recall for MV cable with tape shield it is typically 12 x OD, probably about 12 inches for 1/0 cable.

I was not involved with work covered by the NEC very much since the majority of my career was spent doing utility work. If the contractor can't be compelled to correct the error due to time pressure or whatever my approach in the non-NEC world would likely be to field construct a sheetmetal trough system with generous dimensions to meet the MBR requirements. In principle there should be no issue entering the enclosure through the side assuming MBR is OK internal to the enclosure and you have room for the cable terminations (stress cones). You should probably discuss this with your city/county inspector or whoever has jurisdiction before proceeding. Perhaps you can adapt listed wireway of some sort rather than building something custom, improving your likelihood of the installation being accepted. None of this constitutes engineering advice, engaging an outside consultant can save a lot of headaches and is recommended.

 

[jraef]

I agree on the potential wire bending space issues. In a very similar situation we ended up having a trench cut in the concrete to re-route the conductors through it.


" We are all here on earth to help others; what on earth the others are here for I don't know." -- W. H. Auden

 

[waross]

A bending space problem may often be solved with threaded reducing bushings and over-sized LBs.
We have also used oversized LBs to get the cubic inches needed to make splices in an LB.
Most often when the conductors transition from wire in conduit to flexible cable for whatever reason.

--------------------
Ohm's law
Not just a good idea;
It's the LAW!

 

[power2engineer]

Thanks colleagues for your aanswers - The size of cable is 3#1/0 + GND in 4 "C I thought using LBs would solve the issue of bending radius. Once we use LBs The cable is 15KV, M105, Unshilded. Any comments?

 

[bacon4life]

I assume the that at 15 kV the cable is shielded rather than unshielded.

 

[resqcapt19]

Thanks colleagues for your aanswers - The size of cable is 3#1/0 + GND in 4 "C I thought using LBs would solve the issue of bending radius. Once we use LBs The cable is 15KV, M105, Unshilded. Any comments?

Standard LBs are often not even suitable for 600 volt conductors. In many cases, even the mogul LBs will not be suitable for higher voltage cables.

 

[waross]

What I said.
Oversized LBs.

--------------------
Ohm's law
Not just a good idea;
It's the LAW!