tray bonding

[opm electrical]

what do most do with tray to ensure its bonded, earth tags at each joint like on galv trunking or are the joins substantial enough, only ask as a dont generally use it but its specced on a job to install for data cabling and can i run power cables in the same tray if i keep them segregated?

 

[Essexboy7]

on tray you need to use earth braids at each joint.Dont use earth tags.I cant see why you couldnt run power and data on the same tray as long as they are segregated but i would check the spec to see if there is anything against it

 

[Knobhead]

Have a look at THIS

 

[ian.settle1]

Have a look at THIS

Tony is this a US site?

 

[benji]

generally use wire basket for data lot easier to install, bond at one end if correct joints are used

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generally use wire basket for data lot easier to install, bond at one end if correct joints are used

 

[benji]

bit more info , if your using the basket as part of the earthing system it should be bonded at each end and every 15 mtr of the run
CABLOFIL Couplers
The standard IEC 61537 states that coupler resistance must not exceed 50mΩ. The test involves running an electric current trough the system (cable trays + couplers and measuring coupler resistance.

 

[Spoon]

Nothing wrong with putting power and data cables in the same trunking as long as it has multi-compartments.
We get ours from TOTAL CABLE MANAGEMENT SOLUTIONS - specialists in trunking, cable tray and ladder: Unitrunk

 

[Spoon]

Is it cable tray or trunking you intend to use?
These are the earth links for some cable tray or trunking Earth Link | Unitrunk

 

[Knobhead]

Tony is this a US site?

Read it. Some of the best information you will get. It doesn't go in to reg's it goes in to theory and good practice.

 

[Engineer54]

We always earth our cable trays, which are pretty extensive too. We use two copper earth connections at each joint diagonally opposed. Generally our tray/basket work runs are dedicated to either comm's, LV, MV, but if the need arises i have no problem if space allows, to run LV and Comms on the same tray for shorter distances. All our comms cabling is screened and rated 600V anyway...

 

[johnboy6083]

Personally, I don't see any point whatsoever using copper links on trunking or tray, when solid joiners are used, and fastened correctly.
The lugs are connected to the same steel as the joiners, and have a smaller CSA, and smaller area of contact.
i would like to see a comparison on a long length of tray/trunking, straps vs no straps.
if for any reason fresh air bends are used, then I always use a strap, or use a min of 6mm2 6491x

 

[Engineer54]

Yep!! The manufacturers supply those copper earth joint straps for no reason what-so-ever!!! lol!!!

 

[johnboy6083]

Well, they are driven by other factors other than safety, profit being one of them.
as I've said, less contact area and less CSA the the joiners.
As long as the joiners are at least 8x the CSA of the min size copper link that a said manufacturer would supply then they would be fine. 8x is the difference in conductivity between copper and steel, which would be the worst case scenario.

of course we could then discuss whether the tray would need earthing at all?

its something that I have always done by the way, and will continue to do.

 

[Tesla1980]

I had the lovely job of earthing miles of cable tray in Avonmouth I got some earth cable wound it round a screwdriver for 8 turns or so then round earth crimped both ends and joined the tray up, cheap and cheerfull looked very neat.

They then had me pilot drilling loads of RSJ'S for earthing with sparky going round after me with bigger drill with which was not so great you know when your through you hang on to that 110 drill for dear life.

 

[Knobhead]

It's a wonder they didn't make you take the pigtails out. Bad practice.

Can't see the point of earth links on a bolted joint.