A little off topic but I must say I am impressed, (not really I kind of expect it from this lot) I have listened to so many people who can't keep the whole Hot, Neutral (Grounded), Ground nomenclature together.

Were any of you ever shocked by a xerox machine in the old days, making sure the case is properly grounded ended that old prank. Sad day for office antics.
I recall reading some where, in the US one of the main drives for polarized plugs was the fact we cant seem to switch over to a better (safer) light socket.

There is still a lot of commercial and residential wiring that have hot neutral reversals especially in the older places (like the house I am renting right now). In a small and relatively simple metal box when the source power wiring is unknown a little extra safety for the person who might be touching the case and standing in a puddle of water at the same time isn't all bad.

I am not an electrician or an engineer, nor did I stay at a Holiday Inn Express last night, So if i am completely off base feel free to set me straight.





...split from Why are Hot AND Neutral Connected via Switch on Mazzers? by moderator...

TeMpTiN wrote:There is still a lot of commercial and residential wiring that have hot neutral reversals especially in the older places (like the house I am renting right now). In a small and relatively simple metal box when the source power wiring is unknown a little extra safety for the person who might be touching the case and standing in a puddle of water at the same time isn't all bad.

One of the best reasons to own and use a Woodhead tester (or equivalent).

Psyd wrote:In the US, Hot and Neutral (Live and Grounded) are not interchangeable.

Psyd, I'm surprised that you of all people would call Neutral "Grounded". You've done it twice now. The NEC definitely differentiates between the two and I'm sure a sound engineer is painfully acquainted with the concept of ground loops. Just because neutral is usually connected to ground at the service panel doesn't mean neutral is at ground potential at the receptacle. It probably seldom or never is. Your highlighted diagram clearly shows that neutral is not connected to ground at the switch.

See The Wikipedia article on Electrical wiring:

Wikipedia wrote:Neutral refers to a conductor with continuity to the electrical system's center tap of the power company transformer of a single-phase system, or the center of the wye connection of a polyphase system. American electrical codes require that the neutral be connected to earth at the "service panel" only and at no other point within the building wiring system. Formally the neutral is called the "grounded conductor"; as of the 2008 NEC, the terms "neutral conductor" and "neutral point" have been defined in the Code to record what had been common usage.

More:

Neutral wire is connected to the center tap of the final step-down transformer and is identified by gray or white insulated wire, perhaps with stripes; most commonly bonded to earth for a fixed known path to stabilize the voltages only at the main service panel; many times called the grounded wire. Note that all metallic systems in a building are to be bonded to the panel; e.g., water, natural gas, HVAC piping, etc.

My understanding is that neutral is indeed grounded, but it is intentionally load-bearing. The separate ground wire is for safety, and is not intended to bear electrical current unless something has gone awry, in which case the imbalance on the intentionally grounded neutral connection is detected and the GFCI is tripped.

I think the posts about having a common switch configuration for 110/220 and maybe other countries' voltages is probably a valid reason. The argument about hot/neutral reversal is certainly a valid point too. Not to be a smartass but my impression is that European tradesman standards are generally much higher than here. There a journeyman must go through a rigorous apprenticeship before getting a license. Here, correct me if I'm wrong, it is much easier to get a license. And I'm not sure the code is strictly enforced here either. Just last week I had a licensed electrician of many years (I checked his license numbers) come over to give me a quote on converting/adding a 220V circuit to my kitchen island for a coffee machine. He suggested converting the dedicated 2-wire (hot/neutral/ground) dishwasher/disposal circuit to 220 and pulling the wiring to one of three receptacles on the island inside the sink cabinet and using that for the dishwasher/disposal while still leaving the receptacles intact both of which are code violations. Europeans think Americans are stupid and so they probably assume some tradesman will reverse wire a receptacle. Why risk a lawsuit? Wouldn't the DPST switch remedy this situation rather conveniently? AND read this snippet from the 2008 NEC article on Motors, Motor Circuits, and Controllers:

430.105 Grounded Conductors.
means shall be permitted to disconnect a permanently
grounded conductor, provided the disconnecting
means is designed so that the pole in the grounded conductor
cannot be opened without simultaneously disconnecting
all conductors of the circuit.

Now granted the neutral is not grounded here but I think in a broad interpretation this would still apply in this case to the NEUTRAL. Again why risk a lawsuit? This covers all grounds.

shadowfax wrote:See The Wikipedia article on Electrical wiring:
Formally the neutral is called the "grounded conductor"; as of the 2008 NEC, the terms "neutral conductor" and "neutral point" have been defined in the Code to record what had been common usage.

Hmmmm. I find this most curious and somewhat alarming. Article 100 Definitions of the 2008 NEC states:

Neutral Conductor. The conductor connected to the neutral point of a system that is intended to carry current under normal conditions.

Neutral Point. The common point on a wye-connection in a polyphase system or midpoint on a single-phase, 3-wire system, or midpoint of a single-phase portion of a 3-phase delta system, or a midpoint of a 3-wire, direct-current system.

I don't see any mention of the term "grounded conductor". BTW the definition for that is:

Grounded Conductor. A system or circuit conductor that
is intentionally grounded.

Just goes to show, anyone can write anything at the Wikipedia. Doesn't make it necessarily so. In any case to use the two terms interchangeably, especially in a specification document, would be a big mistake. How long will it be before some journeyman connects the green wire where the white wire should go and vice versa?

In the way i was taught what we call the Neutral wire now, was referred to as the "Grounded", also remember it was a two pole system and the plugs were not polarized. (Grandmas house was Shocking)
The real confusion came about when for safety the Ground (no -ed aka green, or bare wire) started being used in every receptacle.

Then you had Hot, Grounded, and Ground, the problem was people would easily confuse the terms so for clarity and safety the term Neutral was introduced.

To make things more interesting if memory serves the lug that goes to ground in the meter and in the panel is referred to as the grounding conductor.

Edit: upon further review even my terminology is a bit old, technically the Ground (no -ed aka green, or bare wire, The round hole on US plugs) is the ECG (Equipment Grounding Conductor)

I recommend extreme caution when changing light bulbs!

In Holland, we do it like this:
'Fase', which translates to 'phase' for what you call hot
'Nul', which translates to 'zero' for the neutral
and 'aarde' which translates to 'earth' for the ground.

And we've got a real powergrid which can actually supply power instead of crapping out at 1.7kW.

Bluecold wrote:And we've got a real powergrid which can actually supply power instead of crapping out at 1.7kW.

Who doesn't?

Bluecold wrote:And we've got a real powergrid which can actually supply power instead of crapping out at 1.7kW.

Where have you been that it does? That's like the power draw of a $100 microwave in the US.