The puzzle for the day:

A friend has an old Sony radio with a line-voltage selector with positions for 110V, 127V, and 240V. I've never heard of any place that has 127V outlets. I note that 127*sqrt(3)=220, so I figure this voltage comes from a line-to-neutral connection on a 220V wye system.

Does anyone know where they're actually using 127V as a standard wall-receptacle voltage?

This is the old 127/220V WYE system used in Europe and perhaps elsewhere. It is/has been phased out. Most of the countries that used to use it are standardizing on 220 volts only. I think it's most common occurence was the old Spanish/French electrical systems. It may still be used elsewhere in the world but as to where I am not sure. Perhaps some of our non-US members can say more.

So if you use this radio at your house, and if you measured 120 volts at the outlets, maybe you would use the 127v setting as being closer to the 120 volt supply than the 110v setting?

Yes, as Ian said it comes from the old European standard which used 220Y/127 distribution networks, including parts of France and Spain.

Most of these have been converted over to 380Y/220 over the years, but I know that 127V was still in use in parts of France in the 1970s.

Belgium still has 220Y/127 distribution, but now with all loads connected phase-to-phase to get 220.

Some South American countries which were influenced by Eiropean conventions still have 127V, including, if I recall correctly, Brazil.

Old Austrian radios (until around 1970 I think) had an even weirder voltage setting... 150V! I've never heard about a 150V system being actually used anywhere, but one guy on the internet claimed he once saw a black ungrounded receptacle labeled "150V" in a rural transformer station once. He admitted not even the PoCo guy could tell him what it was intended for... but it was live at roughly 150V!
So I assume some independent rural systems started with 150V.

Mexico still has 127/220V (60 Hz) as the standard voltage and a few places, including as mentioned Brazil but also Saudi Arabia, have 127/220V (60 Hz) as one of several systems.

It was once Soviet standard as well (at 50 Hz) and I'm told old systems survive in a couple of places where Soviet engineers were active, like Vietnam. Along with American 120V, French 110V and European 220V of course...

Quite possibly one can find this voltage in other little known corners of the world.

PaulUK:

> Belgium still has 220Y/127 distribution, but now with all loads connected phase-to-phase to get 220.

I wonder where you found this info. It might be the case in a couple of small villages and even very local areas of old towns (though I doubt it) but 127V is an obsolete standard and it is very rare now. Perhaps the source of your info is quite old.

Nearly all domestic or small commercial supplies (eg for shops) in Belgium have supplies at 230V line-to-neutral or 400V line-to-line, with three phases being common for larger houses. The nominal supply voltage was altered from 220 to 230 some time back.

I had 127V in my house in New Jersey some years ago. And no, it wasn't a bad neutral. Turns out the POCO had the town distribution system mis-balanced and many people were getting excessive line voltage. Actually I had 130/260V in the house. It took the POCO a few weeks to get it corrected.

C-H
Yeah, I forgot all about the Saudis and I suspect 127 exists elswhere in the middle east too. I suspected Mexico as well, but I have heard too many conflicting reports about Mehico to say with any certainty.

[This message has been edited by IanR (edited 06-20-2005).]

The power cruises 123-125 at my house, always has.

So what is an acceptible voltage for a 120v device?
A toster would work ok. shorter or longer life?
A computer, shorter or longer?
would some devices have tollerance of some range. like (+)(-) 5% or something?

Thew only thing I seem to have a problem with is light bulbs. I buy 130v when I can.

Bucketman, UL tests most everything to +10% and -15% of the nameplate voltage. Keep in mind that this is testing for SAFETY- there is no expectation that the thing will work properly.
NEMA motor standards use the same range for motor operation.

"So what is an acceptible voltage for a 120v device?
A toster would work ok. shorter or longer life?
A computer, shorter or longer?
would some devices have tollerance of some range. like (+)(-) 5% or something?"

Being that a toaster is juste a heated element (like a lightbulb) I would say higher voltage would shorten it's life but how much I don't know. It would make toast faster As for computers, they use switching power supplies and they would just alter thier duty cycle to compensate for voltage changes, which they are designed for anyway. So, I don't think it will make much difference there. As to acceptable variations I think UL suggests(requires?) something like 108 to 132 volts. Could be misttaken though.

It was our friend "Belgian" who mentioned it on the forum here a few months ago. I can't remember if it was where he lives or somewhere nearby which he said is still wired this way..

Eli, if you're reading this, perhaps you could help us out!

I should have remembered that one. They seem to use British fittings for some (all?) of their work, and the MK (British) catalog lists UK-style dimmers for 127V, as well as NEMA 5-15 configuration receptacles but on a British plate.

Some small rural Communities in Germany, especially close to France still have a 133/230V system w/o neutral. Some guy recently started complaining at another board... "At my aunt's I tried installing a new light and my phase tester glowed on both wires! And then I measured 127V frome each wire to ground, what's wrong there???" Kinda liked that post...
There's one important thing about working on such a system: If it's fused and the circuits aren't labeled, unscrew both phase fuses and not only one!!! Many DIYers will work "if the light's off when i unscrew the fuse it's gotta be safe!" and that's a real abd idea with such a system... you'll still have 127V to ground on one wire.
According to a German expert you'd use the blue wire as a phase in such a system. If I wired in conduit I'd probably prefer black and brown as well as the other accepted phase colors (orange, purple, white, grey, though i'd avoid grey since it used to be neutral).

Odd voltages, as what TEXAS RANGER mentioned 150 Volts. ( they do, did exist )

I have a Moser Baer Masterclock which has primary tappings 110, 125, 145, and 220 Volts.

See if I can make a picture of it

Something at around 145 / 150 V ac must have existed in some parts of Europe otherwise manufacturers wouldn't provide that option.

In older cities in the Netherlands 127 / 220 Volts was used. It is now almost obsolete and mostly 220 Volts is taken between phases.

The power at my house is consistantly in the 123-124v range.

In the earlier part of the 20th century, parts of Adelaide, South Australia had 210 VAC 50 Hz for a while. I remember going to a museum in Adelaide where they had a 240/210 V transformer for when the voltage was changed to the standard 240 VAC

Parts of the U.K. had 210V as well prior to standardization at 240V. In fact the declared normal voltage in different parts of the country was anything from 200 to 250V in 10V increments, with corresponding 3-ph voltages.

We leave our substations with 127 volts everyday 24/7. We set ours with a 1.5 bandwidth so it is possible to leave with as much as 128.5 or 125.5. The 240 side runs about 252 to 255. This is on a system of 22000 customers and very wide spread.

 
Agreeing with C-H, Jefferson electric makes a dytype for Mexico with a 220Y/127V secondary.

ANSI std C84.1 lists an aboslute maximum of 127V on a 120V system, with most utilities limiting that to 125.

127V can be pretty tough on electronics and incandescent lamps.

Years ago, I heard that a small part of the older section of Bogota (capital city of Colombia) had 150 volts. However the nominal voltage in the rest of the city is 120 at 60 hertz.

According to my grandmother, Cali used to be slightly lower (nominal 110V), but according to that city's utility company, the nominal voltage there is also 120...so who knows. When she moved to Bogota, she took her large Philips multi-volt radio and remembers turning the voltage selector knob to 125 (from the 115 spot it was set for).

I don't know if this 150 volt system still exists. Probably not.

As far as 127 volts, I've heard it's the nominal voltage in Mexico...or at least was. Wiring devices and appliances I see imported from Mexico are rated either 125 or 127 volts at x-amps.

I wonder if that's also the case in the USA/Mexico border. Can anyone living in San Ysidro or such border towns give us a voltage reading at their normal wall sockets?

Maybe next time I go visit Tijuana or if I go to Cancun, I'll take a small volt-meter with me. Just for kicks.

Local voltage in New York City is about 118. I've heard of some parts of the USA having voltages as high as 125 or as low as 105.

I have an Army manual that shows a 3 phase 4 wire system, with 220 volts p-p and 127 volts p-n. The 127 volt designation is just 220/1.73=127 volts. It could just be the nominal voltage designation.

Somehow I can't put in a photo to show the 125 and 145 Volts terminal on a masterclock.

I have submitted the piccies to the webmaster, see what happens.

Is this it here Ray?.

Great,

Many thanks Trumpy

Wasn't there someplace where the nominal line voltage was about 250 volts?

That would make some sense.

250/1.73 = 144.5 volts

????

Interesting thought Arend, I didn't think under that angle. I know that in Belgium a 3 x 230 Volts system was used but in the older days some countries and perhaps local hydro powerstations in switzerland may have had some different non standard voltages.
That voltage is on a swiss built clock which I bought on Ebay.

Cheers Ray

In the Netherlands (where I live) electricity was also 127/220 at first.

Until some years ago there were still small parts of the old powergrid active in Amsterdam and Delft (at least that is what i heard).

As far as i heard, all the power grids build after WW2 were of the 380/220 kind (upgraded later to 400/230)

Sometimes, in old places you can still see the fuseboxes with 2 fuses per circuit. Where only 1 is still connected. This is rare to see as most of the fuseboxes have been replaced already during the past 50 years.

In the early days people used 127 volts, after that they used 2 phases of the 127 volt grid to power appliances at 220 volts and nowadays everything is 400/230 volts.

Most old PHILIPS appliances that are stamped with "Made in Holland" are selectable between: 110, 127, 220 and 240 Volts. Even the appliances sold in the 60's and 70's. So i guess some 127 volts services were still used in europe at that time.

- Arend

Sven, 3Ø voltage on USA side is 120/208
......3Ø voltage in Tijuana is also 120/208.

Thanks Arend for that info, I'm originally from Groningen and lived in Haren, Assen en Loon.
All power there was 220 / 380 Volts.

In the military in Leeuwarden we had 380 /660 for the rotary converters for the 115 / 416 Volts 400 Hz. ( 25 years ago ).

As you say the older parts of Amsterdam,Delft may still have it, and I'm aware of parts of oud Leiden still has 2 phase 127 / 220 Volts. The 127 level is not used anymore and most is now 220 Volts because lamps are not made for that voltage anymore in The Netherlands. The Philips and Grundig equipment had these taps provided for on the transformer primary.

It's probably a matter of the insulation level of the older cables may not cope with a 230 Volts to earth level instead of 127 V. The reason why it still exist even as distribution transformers.

I remember doing a troubleshoot on an apartment building at Imperial Beach, CA... (right next door to San Ysidro) My Amprobe showed 123V/121V phase to ground.. SDG&E is pretty good at keeping their voltages in line

I have an old Philips cassette deck from the early/mid 1970s which has those four settings.

I also have some old French-made Moulinex kitchen appliances from the mid 1970s, and the books for those all mention both 220-240V and 127V versions.

I'd guess that 127V was also still in use at that time in at least some of the former French and Dutch colonies in Africa.


[This message has been edited by pauluk (edited 01-02-2006).]