Coco_HueHueHue
Electrical
- Apr 8, 2018
- 49
Hello,
I tried to search Google for this answer, but I always end up falling on websites explaining either how grounding works or why grounding is important...
But, my question is the following: What methods are good to ground a junction box housing splices for multiple 480V feeders in the USA?
I am working on a project in the USA and noticed that the junction box is completely floating.
For your information (context), I am Canadian. The Canadian Code is a bit different in a way that all cables do have a bare copper conductor inside every cable to maintain ground continuity at every feeders.
See page 14/60 at the following link to see what type of cable i am used to work with :
I am not 100% familiar to the NEC, but i do notice that feeders ground continuity appears to be achieve either by:
Main difference between USA and Canada appears to be that Canada requires a ground continuity path for every feeders while USA appears to allow a single ground continuity path for a bunch of feeders as long as it is sized for the most powerful feeder of the bunch and the upstream power source.
That would explain why in a USA catalogue (UL) I would only find that type of TC cable like on page 36/80 :
Anybody in the USA ever used TC cables which have a ground conductor inside of it like in Canada to make ground continuity happen?
Since it is impossible in this project to run the cables in electrical conduits, I assume that I will need to bring a properly size ground wire from an bare ground conductor of the main ground system to the junction box and everything would be fine...
P.S.: I know TC cables should not be running unprotected, I already know that
For your info, this installation is weird and within a hydro generator/turbine bulb unit. Space is limited, there is lot of piping and the shape of the bulb frame makes trays/conduits almost impossible to be installed in a proper way. I already have touched this subject with our client and this is not the essence of this question
Thanks for letting me know your thoughts and comments on this.
Coco
I tried to search Google for this answer, but I always end up falling on websites explaining either how grounding works or why grounding is important...
But, my question is the following: What methods are good to ground a junction box housing splices for multiple 480V feeders in the USA?
I am working on a project in the USA and noticed that the junction box is completely floating.
No grounding bar connected to the main ground...
All cables coming in and out of the box are TC cable not running inside of a cable tray or metallic conduit, they are only running on custom supports fixed with zip ties...
For your information (context), I am Canadian. The Canadian Code is a bit different in a way that all cables do have a bare copper conductor inside every cable to maintain ground continuity at every feeders.
See page 14/60 at the following link to see what type of cable i am used to work with :
I am not 100% familiar to the NEC, but i do notice that feeders ground continuity appears to be achieve either by:
The ground wire running along the cable tray your TC cables are running in (bonding from the junction box to the tray ground cable)
The metallic electrical conduits themselves the TC cables are running within
Main difference between USA and Canada appears to be that Canada requires a ground continuity path for every feeders while USA appears to allow a single ground continuity path for a bunch of feeders as long as it is sized for the most powerful feeder of the bunch and the upstream power source.
That would explain why in a USA catalogue (UL) I would only find that type of TC cable like on page 36/80 :
Anybody in the USA ever used TC cables which have a ground conductor inside of it like in Canada to make ground continuity happen?
Since it is impossible in this project to run the cables in electrical conduits, I assume that I will need to bring a properly size ground wire from an bare ground conductor of the main ground system to the junction box and everything would be fine...
P.S.: I know TC cables should not be running unprotected, I already know that
For your info, this installation is weird and within a hydro generator/turbine bulb unit. Space is limited, there is lot of piping and the shape of the bulb frame makes trays/conduits almost impossible to be installed in a proper way. I already have touched this subject with our client and this is not the essence of this question
Thanks for letting me know your thoughts and comments on this.
Coco