Cable Tray Questions, Can i have multiple points in a single tray ?

[hshaker]

Hi everyone

I'm working on a machine which has this long tray route. This machine is like a 25x10x10 metres dimensions and tray is serving every equipment around it and on top of it. I'll have 3 ground bars on 3 different locations all of them will be connected to a grounding pad on further side of the building.

My questions are:

1- Can i have multiple ground connections on this single tray, for example can i ground the tray on location 1 then can i ground the tray on location 2 and 3 again ? Is this going to cause any problems. Or do i have to ground this tray on location 1 and then i can't ground it again ?

2- I have many equipments being served from this tray. So if i ground equipment 1 on the closest location 1, can i ground my equipment 2 on location 2 ?

3- If i have a motor to ground which has a different tray for 3 phase power transmission. Let's call it tray 1 for power and tray 2 for low voltage signals. Can i ground my motor chassis on tray 2 on location 2 and ground the tray 1 on on location 1 ? I hope that's not too confusing.

Please note these are ground bars and main grounding pad is in a different place connecting all bars together.

Thanks for your answers in advance.

 

[roger]

A cable tray can be grounded as many times as you want. If it is installed in a continuous length (physically joined) it can be the EGC itself.

 

[tom baker]

This is a forum on the NEC and it appears the wiring/grounding is not something we are experienced with

 

[petersonra]

You have to run all the motor conductors together all the way to where they originate including the ground wire.

I am not sure what you mean by grounding in this context. There is no need at all to run a wire to earth in most cases and it serves no good purpose.

You do need to bond all the metal parts together though. You can do it once or ten times if you want. Once is adequate though and more bonding wires is not "better".