Disco Ground

[Alwayslearningelec]

If running EMT to a disconnect on the primary side of transformer do you need to ground the disconnect switch or can the EMT be used as a ground?

 

[augie47]

Generally speaking EMT qualifiers as an equipment ground (250.118).
Depending on the voltage, type enclosure and presence of concentric/eccentic knockoutys a bond jumper mighty be required for disconnect grounding..

 

[infinity]

If the raceway to the transformer has FMC in the run then a wire type EGC is required. Ahead of that not required

 

[Alwayslearningelec]

If the raceway to the transformer has FMC in the run then a wire type EGC is required. Ahead of that not required

So of your running EMT from source to disco to transformer you don't need separate ground wire?
How about if the run starts with EMT from the source then transfers to MC cable then transfer back to EMT? What would happen with the ground wire in the MC when you transfers/splice to EMT? Connect to splice?
What about on the secondary side of the xfrmr if also not using FMC? Would you need a separate ground wire there if using EMT. I know FMC is usually used but this is a temp scenario. Thanks.

 

[infinity]

So of your running EMT from source to disco to transformer you don't need separate ground wire?

If the run contains only EMT that is correct. You do not need a wire type EGC or SSBJ in either of the EMT raceways.

How about if the run starts with EMT from the source then transfers to MC cable then transfer back to EMT? What would happen with the ground wire in the MC when you transfers/splice to EMT? Connect to splice?

The EGC for the MC cable would terminate to the metal box and the EMT connector would connect the box to the EMT EGC which is the actual raceway. No wire type EGC is required in the EMT.

What about on the secondary side of the xfrmr if also not using FMC? Would you need a separate ground wire there if using EMT. I know FMC is usually used but this is a temp scenario.

If you used EMT from the transformer out of the secondary then the raceway can serve as the SSBJ without the use of a separate wire type SSBJ.

Just note that in every case you still need an EGC or an SSBJ in each segment of the run. EMT can serve as both. Also terminology is important. I've used the correct terms that you would be able to find in the codebook. IMO you need to learn them and not use the terms in red.

 

[Alwayslearningelec]

If the run contains only EMT that is correct. You do not need a wire type EGC or SSBJ in either of the EMT raceways.


The EGC for the MC cable would terminate to the metal box and the EMT connector would connect the box to the EMT EGC which is the actual raceway. No wire type EGC is required in the EMT.

If you used EMT from the transformer out of the secondary then the raceway can serve as the SSBJ without the use of a separate wire type SSBJ.

Just note that in every case you still need an EGC or an SSBJ in each segment of the run. EMT can serve as both. Also terminology is important. I've used the correct terms that you would be able to find in the codebook. IMO you need to learn them and not use the terms in red.

Thank you.