Grounding NEMA 4X boxes.

[zach_zachary1@yahoo.com]

I work a large municipal wastewater plant. We have 40-50 pole mounted 480 volt 2 phase, high pressure sodium area lights. Its aluminium conduit with a NEMA 4x stainless steel junction box at the base of the light pole. These NEMA 4x boxes contain splices. None of the boxes are grounded. There is an equipment grounding conductor but the egc is not grounded to the box. Does the NEC require these boxes to be grounded? Are there exemptions?

Thanks!

 

[petersonra]

I work a large municipal wastewater plant. We have 40-50 pole mounted 480 volt 2 phase, high pressure sodium area lights. Its aluminium conduit with a NEMA 4x stainless steel junction box at the base of the light pole. These NEMA 4x boxes contain splices. None of the boxes are grounded. There is an equipment grounding conductor but the egc is not grounded to the box. Does the NEC require these boxes to be grounded? Are there exemptions?

Thanks!

Why can't the aluminum conduit be the EGC that bonds the box?

 

[iwire]

I work a large municipal wastewater plant. We have 40-50 pole mounted 480 volt 2 phase, high pressure sodium area lights. Its aluminium conduit with a NEMA 4x stainless steel junction box at the base of the light pole. These NEMA 4x boxes contain splices. None of the boxes are grounded. There is an equipment grounding conductor but the egc is not grounded to the box. Does the NEC require these boxes to be grounded? Are there exemptions?

Thanks!

They are grounded via the conduit, however 250.148 requires the EGC to be connected to the box.

 

[petersonra]

They are grounded via the conduit, however 250.148 requires the EGC to be connected to the box.

I would be curious as to just where that EGC goes. Where else would it logically be terminated?

 

[don_resqcapt19]

I would be curious as to just where that EGC goes. Where else would it logically be terminated?

I would guess that the EGC continues on to the fixture and is terminated there.

 

[zach_zachary1@yahoo.com]

I would guess that the EGC continues on to the fixture and is terminated there.

That is correct.

 

[don_resqcapt19]

That is correct.

Assuming that the conduit from the junction box is solidly connected to the fixture, or connected by a wiring method that is suitable for use as an equipment grounding conductor (note that flexible conduit installed where flexibility is required, is not suitable for use as an EGC), I don't see a safety hazard, but the since the conductors are spliced in the box, the code requires the EGC to be connected to the box.

 

[xformer]

They are grounded via the conduit, however 250.148 requires the EGC to be connected to the box.

250.148 applies only if splices are made in the box.

 

[iwire]

250.148 applies only if splices are made in the box.

I know and I agree.

These NEMA 4x boxes contain splices.