Cable Tray Grounding Locations

[0leehill0]

In a industrial plant application, does the ground conductor on a cable tray have to be grounded to the grid at multiple points or can it just be at one location, such as the electrical building?

 

[edavis2293]

Cable Tray Grounding

Cable Tray Grounding

Cable tray can be connected to the grid anywhere but is not required to be connected to the grid anywhere.

 

[weressl]

Cable tray can be connected to the grid anywhere but is not required to be connected to the grid anywhere.

Really?

392.7 Grounding.
(A) Metallic Cable Trays.​

​

​

​

​

Metallic cable trays that support electrical conductors shall be grounded as required for conductor enclosures in accordance with 250.96 and Part IV of Article 250.​

 

[walton]

Make sure the cable tray has an adequate bond jumper between each section. One grounding point to the grid would then be enough.

 

[Smart $]

Make sure the cable tray has an adequate bond jumper between each section. One grounding point to the grid would then be enough.

General facts, but code references may be dated...

http://www.cabletrays.com/techbl12.htm

 

[jdsmith]

In a industrial plant application, does the ground conductor on a cable tray have to be grounded to the grid at multiple points or can it just be at one location, such as the electrical building?

Depends on the job specs. My plant specs call for the tray to be bonded to the ground grid every 100 ft. The intent is to minimize touch potentials.

To be sure you meet 392.7(A) you need to install bonding jumpers around any expansion joints and horizontal and vertical adjustable splice plates.