Equipment Ground
Equipment Ground
(OP)
I have a switchgear cubical with a ground bus. The case is all grounded through the ground bar. The bar is connected to a local ground, and the 4160v feeder ground. We have multiple power circuits terminating in the switchgear, 120VAC, and 125DC. Do I have to pull a ground cable and terminate it for every circuit? The vendor only provided terminations for local and feeder ground.





RE: Equipment Ground
The cable tray system has to be continuous and the grounding connections through approved [for grounding] appurtenances.
The cable tray system has to be connected to the Grounding Bus.
The cable tray has to be suitable to convey the grounding current-for instance steel cable tray current is limited to 600 A and aluminum
up to 2000 A.
Usually starting from the cable tray the cable rigid steel conduit should be connected by a jumper to the cable tray and at the receiver end another
jumper will connect the conduit to the receiver grounding point. Sometime the flexible conduit could be an approved grounding mean.
RE: Equipment Ground
Bill
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"Why not the best?"
Jimmy Carter
RE: Equipment Ground
RE: Equipment Ground
is not sufficient. All structural metallic parts, including cable trays, metallic ladders or pipes could be connected directly to the grounding ring in order
to mitigate the touch potential but this way does not present a low impedance in order to put the protection in operation.
RE: Equipment Ground
No. For an equipment grounding conductor to be an effective fault return path, it needs to be physically close to the phase conductors. When the grounding conductor is outside the conduit and physically distant from the phase conductors, the inductive reactance is much higher resulting in higher circuit impedance.
If this installation is in the US and under the NEC, you have to have an equipment grounding conductor run in each feeder conduit. As 7anoter4 indicated, steel conduit, cable tray and other raceways are allowed to be used as equipment grounding conductors in some situations. But regardless of this, we always run a ground wire in every conduit. No exceptions.