Blecher_onthe_Hudson t1_j8egw0j wrote
Reply to comment by fossfirefighter in Electrocuted in my apartment in JC after two years of complaining about the wiring, what next? by fossfirefighter
>there was a short that the electrician resolved.
A short in the outlet box or in the device plugged in? You're not being clear. It's perfectly legal under 'grandfathered code" to have an ungrounded outlet, what's illegal is to put a 3 prong receptacle there that is ungrounded.
Where a lot of confusion arises is whether the metal clad cable is legal to use as ground. The problem is the older cable is not, it does not have the bonding strip inside that later AC cable does. But some people will use the metal box/cable as ground anyway. It will show as properly grounded on a tester, but certain circumstances can fail to conduct enough current to trip the breaker.
A partial solution is to add GFCI receptacles to ungrounded outlets. Not perfect, but safer.
pixel_of_moral_decay t1_j8f26ru wrote
This is all absolutely correct.
Last I checked MCC cable can be used as ground and if it was installed to code (no gaps and securely clamped to the boxes) should operate as such. I personally put ground pigtails in boxes to outlets/switches for added protection since paint on the outer part of boxes can act as an insulator. I don’t trust the contact a device will have with the box as grounding in these cases, and for $10 I don’t see why I would. Still gfci anywhere I think it can be handy, I go beyond code. I have one near my desk for example where I handle electric devices more commonly.
This sounds like the classic “I wanna break my lease but need a reason so I don’t have to pay” scheme.
They even make online gfci adapters if you want to protect a device and not change the outlet (for renters).
I’d wager 1/4 of apartments in NYC have no grounding on most of their outlets due to being older buildings. It’s hardly uncommon.
And most people will never experience a fault that actually triggers this scenario. Especially with modern day devices.
Blecher_onthe_Hudson t1_j8f8wl4 wrote
>This is all absolutely correct.
Haha, I love to see those words! Just to clarify for the crowd since obviously it's easy for unversed folks to get confused, you referred to 'MCC', meaning "metal clad cable". But there's at least 3 varieties we encounter.
1: Old steel armored cable, frequently called BX, though that was a brand name. It has no bonding strip and therefore is not legal to use as ground. Obviously not on the market anymore
2: 'AC cable', an industry term for steel armored cable with the bonding strip making it legal for grounding use
3: 'MC cable' armored in aluminum, which would make it not legal for grounding, so it comes with a green wire for ground, unlike AC. So a 12-2 MC cable has 3 conductors, black, white and green, same as a Romex (again name brand) or NM (non-metallic) cable
>I personally put ground pigtails in boxes to outlets/switches for added protection since paint on the outer part of boxes can act as an insulator. I don’t trust the contact a device will have with the box as grounding in these cases, and for $10 I don’t see why I would.
Better electricians pigtail everything, so if there's a receptacle failure it doesn't break the continuity, especially of the neutral, to the downstream boxes. Wago type push in connectors beat the hell out of wire nuts for this, and everything.
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