Grounding flex tray

Status
Not open for further replies.
C

Crossboss

Member
Location
Oklahoma city
Occupation
Journeyman wireman
Running flex tray in wooden structure, and contains only non power conductors. What size ground wire do I need and how do I find out how to determine that?. And using the proper amount of ul splices do I need to provide jumpers or bond at more than one location if tray is unbroken? TIA!👍🏻
 
Crossboss said:
Running flex tray in wooden structure, and contains only non power conductors. What size ground wire do I need and how do I find out how to determine that?. And using the proper amount of ul splices do I need to provide jumpers or bond at more than one location if tray is unbroken? TIA!👍🏻
Click to expand...
EGC size is found in table 250.122.

You might need to read the manual to see how the bonding of sections works but probably you only have to bond to it once, but you may need to use the tray to bond to downstream stuff
 
There would be no required size based on Table 250.122 if there are no power conductors.
I thought there was a rule in Article 725 that specified a 10 AWG bonding conductor, but I did not find it.
There is a rule in 392 to require bonding between sections of the tray containing non-power conductors but that does not specify the size of the bonding conductor.
392.60(A) ...Metal cable trays containing only non-power conductors shall be electrically continuous through approved connections or the use of a bonding jumper. ...
Click to expand...
 
If this is B Line Flex Tray, I believe their clamps that connect one section to the next are listed for grounding. I'd hope so for what all the piece parts of Flex Tray cost... I had it installed in many labs and it typically just held cat5 and fiber. The electricians typically grounded it with #6 since that is the size that can be run where exposed to physical damage. They also would run it the length of the try and split bolt it to each segment. That was overkill, but we were paying...
 
I thought Is this what the code calls a cable routing assembly ( see art 100 definition), but it is not. What do the instructions say about bonding? So its not clear how to bond.
 
Last edited:
I don't have instructions. I just ordered it! If you use the proper amount of UL listed splices it does establish a ground fault path if it is grounded and would only need to run copper the length of or have bonding jumpers at splices to be considered an EGC. I'm just grounding to establish ground fault path and cannot find anything for sizing the size of conductor needed.
 
don_resqcapt19 said:
There would be no required size based on Table 250.122 if there are no power conductors.
I thought there was a rule in Article 725 that specified a 10 AWG bonding conductor, but I did not find it.
There is a rule in 392 to require bonding between sections of the tray containing non-power conductors but that does not specify the size of the bonding conductor.
Click to expand...
Yes that table is of no help in this situation.
 
Status
Not open for further replies.
Top