bruto
Penultimate Amazing
The neutral is horizontal. On polarized outlets the neutral is always the wider prong.
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120 V or 240 V Mains - which voltage is better?
- Thread starter psionl0
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- electricity
P.J. Denyer
Penultimate Amazing
Full size Ranges (cookers in the UK) are hard wired into a dedicated 20A ring with it's own fuse or RCD, depending on the age of the wiring, and a wall switch (in addition to controls on the oven and/or hob).
Washing machines, tumble driers, dishwashers, fridges, microwave ovens, countertop halogen ovens, toasters, kettles, pizza makers, etc all use the standard three pin plug.
P.J. Denyer
Penultimate Amazing
Your cooker.
That said, I'm just under fifty and I can just about remember the council house I grew up in having a different type of plug, a circular three pin with a round center earth pin and a rectangular live and neutral either side in a straight line. I still have an appliance (a radiant heater that would never pass H&S legislation these days but can heat a freezing room in minutes) that I remember being fitted with one. I've also encountered small, round pinned 3A plugs in a couple of places, the last was a Harvester Restaurant less than five years ago, but these are pretty much exclusively used for low power lighting. They were used in pubs to stop people unplugging the lamps to either plug in something else... Or steal the lamps.
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Jack by the hedge
Safely Ignored
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Those unfused 3 round pin 15A and 5A plugs were the UK standard until the fused 13A version arrived but that was not long after the war. They remained in UK use for stuff like theatrical lighting rigs and they're still used in S. African and India. Maybe other places too. My parents' 1930s house still has a bunch of those outlets but they're not live any more (though they were when I was a kid in the '70s).
novaphile
Quester of Doglets
Oddly enough, I used to have a bunch of fold-over plastic covers to prevent that from happening. They were very cheap, perhaps a dollar for a packet of ten?
I'm struggling to think if I could find one now, because I don't have any short-cord power tools anymore...
(They're still around, but cost $5 ea now!)
https://www.bunnings.com.au/hpm-extension-lead-safety-cord-lock_p4337970
Trebuchet
Penultimate Amazing
Stuff that amuses me: "Cooker". In the USA it's a "stove" or "range". We only have "slow cookers".
Somewhere beneath my propane cooktop is the wiring for an electric one, or electric range. The breaker for that is off. But at least we have the option if we want to change in the future.
Back about 1980, the "slide in" range in our first house expired. I probably could have gotten an element, but it was "avocado" in color, courtesy of the late 1960's, and my wife wanted it gone. I pulled it out, modified the cabinetry, and installed a new freestanding one. The slide-in was hard wired, I had to install a 240V receptacle for it. I also did some other wiring in that house. As far as I know, it hasn't burned down yet.
I haven't yet done any wiring in our new house. Emphasis on "yet".
Somewhere beneath my propane cooktop is the wiring for an electric one, or electric range. The breaker for that is off. But at least we have the option if we want to change in the future.
Back about 1980, the "slide in" range in our first house expired. I probably could have gotten an element, but it was "avocado" in color, courtesy of the late 1960's, and my wife wanted it gone. I pulled it out, modified the cabinetry, and installed a new freestanding one. The slide-in was hard wired, I had to install a 240V receptacle for it. I also did some other wiring in that house. As far as I know, it hasn't burned down yet.
I haven't yet done any wiring in our new house. Emphasis on "yet".
psionl0
Skeptical about skeptics
psionl0
Skeptical about skeptics
Another case of backward thinking. The neutral wire can't possibly carry more current than the live wire and at the junction box, the net current should be zero if the loads are balanced.
bruto
Penultimate Amazing
It does seem backwards, but in a two wire system, although the potential to ground is zero from the neutral, and though it's grounded and currentless at the breaker box, it's carrying load between breaker box and appliance. It's one reason that proper installations these days include both a neutral and a ground wire, even though they are at the same potential, and why it's against code to wire the ground and neutral terminals together on an outlet. The neutral carries current, but the ground (we hope) does not.
Why the wide terminal is neutral is a bit of a mystery, and it may just be an arbitrary choice that stuck, but I speculate that, especially in the older two wire polarized system, where there is no separate ground, it was thought safer to give the neutral higher ampacity, and a more foolproof connection, than the hot, as a neutral failure would be more deadly. Remember too that the original polarized outlet and plug system was shared by both AC and DC. But I would not be surprised to find that the real reason is that Thomas Edison flipped a coin.
a_unique_person
Director of Hatcheries and Conditioning
Hence the mandatory use of RCD breakers. They have probably saved many lives.
Most if not all plugs and sockets were developed before RCD breakers became available: fuse wire and cartridge fuses were used back then.
RCD breakers have made things safer. Maybe the USA would have adopted higher voltages if RCDs had been available many years earlier.
In general, higher working voltages are better, providing that the risk of electrocution can be kept acceptably low,
RCD breakers have made things safer. Maybe the USA would have adopted higher voltages if RCDs had been available many years earlier.
In general, higher working voltages are better, providing that the risk of electrocution can be kept acceptably low,
P.J. Denyer
Penultimate Amazing
Or simply so the neutral can't under any circumstances be shoved into the wrong hole. UK earth pins are bigger, even if someone uses a broken up or dismantled plug (some designs allow the pins to be removed) they can't push the earth pin into the live hole and (for example) make a metal external casing live. Of course they could misswire the plug but that's a seperate issue. It's also worth considering that where electrical devices are connected, deliberately such as amplifiers, or through faults or errors, that may be on separate power supplies, it is conceivable that a fault could lead to more current needing to be discharged to earth than is being supplied through a single live pin.
bruto
Penultimate Amazing
I suppose now that you put it that way, it makes sense. If you put the hot pin to ground, you might get an instant short, spark, and blown fuse. But if you reverse and put the ground to hot, the results are less immediate and more deadly.
It's not that hard to get some two-wire polarized devices plugged together wrong. Old TV's and radios with common ground chassis were pretty easy, and the result could be a nasty jolt or worse.
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BowlOfRed
Master Poster
From the shared 110/220 outlet idea, I had never seen one of these before, but it's a dual outlet with one side 110 (nema5) and one side 220 (nema6). https://www.leviton.com/en/products/5844
So some folks do use things like this (with the hit to wiring cost), but you can use standard 220 plugs in it.
So some folks do use things like this (with the hit to wiring cost), but you can use standard 220 plugs in it.
bruto
Penultimate Amazing
An interesting idea. I don't see it having a lot of use in domestic applications unless they start making more 240 volt appliances, but I wouldn't mind a couple of those in my shop.
If you're currently having to run two sets of wire, one for 240 and one for 120, going to a single three-wire plus ground would end up as a saving.