Bonded or not bonded

[dm9289]

I will attach pictures there are 4 vertical rigid conduits on the inside of a metal I-beam, attached to the I-beam using strut. The bottom of the RMC is open then it transitions to cable tray that is supported by angle attached to the I-beams. Is this considered bonded?

My first impression was it was poor workmanship and it needed bond bushings. But…. I guess the cable tray is connected to I-beam, I-beam is connected to the strut which connects to the RMC.

Your feedback is appreciated

 

[augie47]

I would question on two Code Sections:

392.12(G) For raceways terminating at the tray, a listed cable tray clamp or adapter shall be used to securely fasten the raceway to the cable tray system. Additional supporting and securing of the raceway shall be in accordance with the requirements of the appropriate raceway article. For raceways or cables running parallel to and attached to the bottom or side of a cable tray system, fastening and supporting shall be in accordance with the requirements of the appropriate raceway or cable article.

392.30(B) Where cable trays support individual conductors and where the conductors pass from one cable tray to another, or from a cable tray to raceway(s) or from a cable tray to equipment where the conductors are terminated, the distance between the cable trays or between the cable tray and the raceway(s) or the equipment shall not exceed 1.8 m (6 ft). The conductors shall be secured to the cable tray(s) at the transition, and they shall be protected, by guarding or by location, from phys cal damage.

 

[jaggedben]

Unistrut and building steel are not in the list of permitted EGCs in 250.118. You need something else run with those circuit conductors.

 

[suemarkp]

Unistrut and building steel are not in the list of permitted EGCs in 250.118. You need something else run with those circuit conductors.

How about the other end of the raceways? Do they terminate in a panel or box that is grounded? I believe you only need to ground one end of the raceway. Now the tray itself may also need to be bonded, but we can't see that either.

 

[dm9289]

Unistrut and building steel are not in the list of permitted EGCs in 250.118. You need something else run with those circuit conductors.

Thank you for your reply my immediate thought was this was wrong but I think I over thought it. I was think you could use building steel as a conductor. Perhaps that’s more related to GEC

 

[dm9289]

I would question on two Code Sections:

392.12(G) For raceways terminating at the tray, a listed cable tray clamp or adapter shall be used to securely fasten the raceway to the cable tray system. Additional supporting and securing of the raceway shall be in accordance with the requirements of the appropriate raceway article. For raceways or cables running parallel to and attached to the bottom or side of a cable tray system, fastening and supporting shall be in accordance with the requirements of the appropriate raceway or cable article.

392.30(B) Where cable trays support individual conductors and where the conductors pass from one cable tray to another, or from a cable tray to raceway(s) or from a cable tray to equipment where the conductors are terminated, the distance between the cable trays or between the cable tray and the raceway(s) or the equipment shall not exceed 1.8 m (6 ft). The conductors shall be secured to the cable tray(s) at the transition, and they shall be protected, by guarding or by location, from phys cal damage.

Thank you so much for your reply. The highlighted text 392.12g is very interesting to me. I have seen conduit often short of tray and not attached to tray like the picture. It appears that is not code compliant. But the second reference seems to say it’s ok less than 6ft. I’m a little fuzzy on this

 

[dm9289]

How about the other end of the raceways? Do they terminate in a panel or box that is grounded? I believe you only need to ground one end of the raceway. Now the tray itself may also need to be bonded, but we can't see that either.

Other end does hit large grounded control panel. Thank you for your help

 

[augie47]

Other end does hit large grounded control panel. Thank you for your help

I made note of that Section due to the wording The conductors shall be secured to the cable tray(s) at the transition, and they shall be protected, by guarding or by location, from phys cal damage.
It appeared that might not be the case in your installation

Thank you so much for your reply. The highlighted text 392.12g is very interesting to me. I have seen conduit often short of tray and not attached to tray like the picture. It appears that is not code compliant. But the second reference seems to say it’s ok less than 6ft. I’m a little fuzzy on this

It isn't apparent. Is there an EGC run with the phase conductors in the conduit??

 

[david]

Other end does hit large grounded control panel. Thank you for your help

There is a difference between 250.86 and 250.96

What you stated would meet the requirement in 250.86 the raceway is bonded to an equipment ground to effectively clear a fault. The raceway it's self is not being used as an equipment ground

250.96 would be applicable anytime you have individual branch circuit or feeder conductors in a metal raceway. The raceway system when properly installed the most effective equipment ground. The wire type equipment ground andthe raceway type equipment ground must provide a paralleled path.

When the raceway it's self is being used as an equipment ground It must be bonded to an equipment ground on both ends

 

[suemarkp]

When the raceway it's self is being used as an equipment ground It must be bonded to an equipment ground on both ends

I don't see where the code says this. Its not in 250.86 or 250.96. It just says needs to be connected to an EGC and implies an indirect connection is OK since raceways get grounded through the enclosure and the enclosure gets the EGC.

 

[david]

Thank you so much for your reply. The highlighted text 392.12g is very interesting to me. I have seen conduit often short of tray and not attached to tray like the picture. It appears that is not code compliant. But the second reference seems to say it’s ok less than 6ft. I’m a little fuzzy on this

The conduit in the picture should only be for physical protection, for cable type wiring mythods 250.86.

 

[david]

Thank you so much for your reply. The highlighted text 392.12g is very interesting to me. I have seen conduit often short of tray and not attached to tray like the picture. It appears that is not code compliant. But the second reference seems to say it’s ok less than 6ft. I’m a little fuzzy on this

The conduit in the picture should only be for physical protection, for cable type wiring mythods 250.86.

 

[david]

I don't see where the code says this. Its not in 250.86 or 250.96. It just says needs to be connected to an EGC and implies an indirect connection is OK since raceways get grounded through the enclosure and the enclosure gets the EGC.

I'm not saying a wire type bond. I'm saying the raceway in 250.96 has to gaulify as an equipment ground
Post #2 listed adapters would make that bond to the tray

 

[dm9289]

I made note of that Section due to the wording The conductors shall be secured to the cable tray(s) at the transition, and they shall be protected, by guarding or by location, from phys cal damage.
It appeared that might not be the case in your installation

It isn't apparent. Is there an EGC run with the phase conductors in the conduit??

Yes they are control cables for a small drive and some 120v I/O a contractor was running for my employer.

 

[dm9289]

Uh

The conduit in the picture should only be for physical protection, for cable type wiring mythods 250.86.

i was think from the standpoint of all metal parts needing bonded. I work 12 hr maintenance shifts often at night and tend to look at things too often. I’m just trying to improve my knowledge and appreciate the replies

 

[dm9289]

I made note of that Section due to the wording The conductors shall be secured to the cable tray(s) at the transition, and they shall be protected, by guarding or by location, from phys cal damage.
It appeared that might not be the case in your installation

It isn't apparent. Is there an EGC run with the phase conductors in the conduit??

Also can you clarify do you believe the conduit not being connected directly to the tray is ok?

 

[augie47]

All the tray installations I have been acquainted with had the conduits secured to the tray but I can't confirm if that's a requirement. I'm hoping someone with more CT experience will chime in but from what I read in the Sections posted they would not need to IF they supported individual conductors and 392.10 dictates that single conductors must be 1/0 or larger.

392.30(B) Where cable trays support individual conductors......................................

but lets hope you get a more authoritative answer.....

BLine has an installation manual that you can download and might get an answer,.

 

[david]

.You already gave the answer. What does the article for the conduit raceway require