Air Gapping Electrical 2

[carterav]

Does anyone know of any standards that provide direction about how to air gap electrical to prepare for D & D?

 

[davidbeach]

Dungeons and Dragons?

Air gap?

Generally if work is to be done on electrical equipment it is grounded, not "air gapped".

 

[carterav]

Decommishioning and Demolition.

The MCCs will be locked out and 'Air Gapped'.

 

[DRWeig]

Air gapped?

I, too, would like to know what that term means.

Goober Dave

 

[carterav]

All I have found is the following:

Air Gap: a physical separation that isolates a connection to a voltage source or potential. Reconnection of physical separation shall require extreme effort, or shall be impossible.

physical act of cutting a 12” to 24” section of raceway/cable. AIR GAPPED.

I can't seem to find anything in the NEC or IEEE and I was hoping I could get some help from this site.

 

[carterav]

Labels are applied to the Air Gapped conduit/cable, utility or equipment scheduled for dismantlement activities.

Sorry for the misspell Dave. I should have said Decommissioning and Demolition (D & D).

 

[DRWeig]

Ah, thanks!

I've never run into this, but you're in the right forum. Someone with experience will answer soon I bet.

Good on ya,

Goober Dave

 

[ScottyUK]

The demolition guys like to see a physical separation between whatever they are working on and whatever they are not (supposed to be) working on. That's where the term 'air-gapped' comes from. We would probably trust a locked breaker, but a visible gap in cables, pipes, etc gives them a visual and definite disconnection from any type of service. I've also heard it described as 'blue sky', although in this part of the world they would wait a long time.

As for standards, I'm not aware of any. The demo guys don't trust normal isolation devices, so the standard becomes 'whatever they will accept'. Most will accept a gap of a few inches, as long as it is clearly visible.


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If we learn from our mistakes I'm getting a great education!

 

[davidbeach]

So, everything visible is "air gapped" but the source of power that comes in out of the slab is invisible and therefore left in place. Nice. Like I mentioned, visibly grounded is so much more effective.

 

[IndianTechEngg1001]

I am also with Mr. Scotty. I have also seen that while doing any maintenance people believe what they see. Air gaped between contacts is something which people can trust for safe working.

I have seen people preferring breakers with fuses over MCCB as that can takeout the fuses and put them in pockets while working.