Using a European Motor Appliance (Vacuum Cleaner) on Two-Phase 240V US Supply

Should be no problem what so ever. Be sure the outlets have an earth (ground) pin and is connected to the cleaner.

I've got to ask, why did you buy it?

It cost half as much as the 120V version. I guess Miele isn't seen as so much of luxury brand in Europe as it is in the Americas. Someone told me I might have overheating problems, especially since I'd be using thicker 'AirClean' bags and a HEPA filter. And the vac won't last as much. :(

The only problem I can see will be one of your own making, changing the bag and filter.

Most vacuum cleaners use a universal motor which the change of frequency won't affect all that much as they act like a DC motor.

I have a Miele vacuum cleaner myself (I was given it) but I'm afraid I'm not going to pull it to pieces to check on the motor for you.

TonyS, the bags and HEPA filter are Miele originals and the filter actually came with the thing. The thicker bags are the only replacements Miele sells, apparently. The one that came in the box isn't as thick, but I'll try it out first. :-) I'll run the thing next week when I get back home. Fingers crossed! :D

Oh, all my outlets are grounded but the cord is 2-pin only. Is that a problem?

No problem, no ground, no cry. Vacuum users have 2 wishes:

Live in a vacuum with less dust around. Miele is OK. I use it already 15 years on 60 Hz, same voltage. Also inductive cooking and other appliances. Just better and developed with an eye for design and comfort. The vac is pretty quiet, especially when in the cupboard.

Yeah, it's really quiet in the box too. X-D I just *might* take a look inside this thing just to be sure. I'm assuming it's a universal motor and the speeds are set with a potentiometer. We'll see.

If it's a 2 wire plug, is it polarized? i.e. is one of the spade pins wider then the other to polarize it with the Hot and neutral (240V non US power) wall receptacle?

Is the vacuum 100% plastic exterior? Is there any marking indicating double insulated?

My concern is that the neutral wire is assumed to be at ground potential and when connected to 240, where this (US power which is not 2 phase) is L1 and L2, it makes a hot chassis if the neutral is connected to or not isolated from chassis. Double insulated would indicate that both power leads are isolated from the chassis. This would be safe.

Ignator, everything seems plastic (and a very plasticky plastic at that). The handle has a little metal strip for stactic discharge. EU plugs aren't polarized. Brazilian phase+neutral ones are (phase-ground-neutral) but this is two-phase (legal in the few 120 states).

I wonder what that metal strip is connected too. As there is no safety ground in the cord, it certainly would be chassis, but as you've indicated there is no polarization, on the plug end, there should be no connection (of chassis) to either power wire. An ohm meter would be a good test to validate that.

The worst you would get is an 120volt shock (here in the US). Under the wrong circumstances, it could kill you, and if it didn't (kill you) you'd know that your vacuum is not double insulated.

I got shocked by 24VAC the other day working on the condensing unit of my neighbor, I didn't like that one bit.

I think it's illegal, under EU rules, to connect neutral to chassis (or anything else to chassis for that matter), and this vac has a CE label. I wonder if there's any power loss from using a phase+phase 240V setup (90 deg. difference in phase) vs. a phase+neutral one? Too many questions I know! But I can return this unit a get a (much more expensive) 120V one if it's not worth keeping it.

You have to think of a transformer secondary that the primary is connected between any 2 of the 3 phases.

This secondary is then single phase. And it has a center tap. The total voltage across this secondary winding is 240V, and this ends of this winding is 180 degrees phase difference.

The center tap is then neutral and grounded at the transformer, and also at the service entrance of the residence.

So since neutral is center tap, the voltage from this to either Line1 or Line2 (L1, L2) is 120V.

I believe the only difference in a 240V system is one of the leads of the transformer is grounded and called neutral, and there is no center tap.

There should be no power differences unless the 50Hz 60Hz is a problem with a marginal universal motor quality as stated anther poster.

Many errors in both thinking and understanding, sorry to be so unfriendly.

Generally a house in the 60Hz 120VAC part of this world gets fed with a SINGLE (nominal) 240VAC PHASE, often via a transformer hung on a pole in front of the house). Center tapped to provide the neutral for 120VAC loads. (how many times must we state this on CR4??)

This is why the phase difference between "phase connections" is exactly 180°, always, but it is actually in fact, always 1 phase......not two.

If two separate phases were used from a 3 phase supply, there would be a difference of 120°. (360° divided by 3 =120°. OK?)......this would mean that the voltage measured would further vary with the "difference" between the two phases. You have to think in 3D almost!!

By the way, universal motors live up to their name, they do not care whether 50 or 60Hz and would generally would run on the same voltage from a DC source, then they might get a bit warmer maybe....

If anything I have written here is not understood easily (sorry!), just ask me or any of the other good people here for more detail. Your choice.

Andy, that's what I said. In my rural location that is a group of homes that have no need of 3 phase, only a single phase high voltage (I believe 1200V) and it's neutral is ran down the poles, and every 3-4 homes a transformer is installed (I think they are 25KVA size).

However I've seen 3 phase high voltage distributed running in residential areas, and connected to a low voltage transformer producing the single phase 240 volt distribution. This is what I was referring too of 2 of the 3 high voltage phased connected to a transformer producing single phase low voltage end user power. I think this depends (3 phase vs 1 phase on the power poles) if there are any commercial users wanting full 3 phase low voltage for their business along the distribution path.

And I was trying to communicate that this low voltage is not 2 phase. I don't understand what I wrote was confusing.

See my second line by line answer to your previous post.

I didn't notice any unfriendliness! And I'm a complete ignorant when it comes to electrical engineering - which is why I searched for an EE forum to ask questions. :-)

I will try and answer your post line by line for you as you appear not to understand fully in your next post as to what I am talking about!

You have to think of a transformer secondary that the primary is connected between any 2 of the 3 phases.

Should have read as follows:-

You have to think of a transformer primary that is connected to a single HV phase, usually Delta, but could be HV phase to middle point on a star transformer, though I am unaware of such connections personally.

Suffice to say, a single phase ONLY may be connected to a single phase transformer, not two phases!!....obviously!!

This secondary is then single phase. And it has a center tap. The total voltage across this secondary winding is 240V, and this ends of this winding is 180 degrees phase difference.

You would have a strangely variable output when connected to 2 phases at 120° apart. I have never tried it personally....

The center tap is then neutral and grounded at the transformer, and also at the service entrance of the residence.

The secondary is center tapped and also linked to ground to provide a neutral return for the 120VAC devices.

So since neutral is center tap, the voltage from this to either Line1 or Line2 (L1, L2) is 120V.

I believe the only difference in a 240V system is one of the leads of the transformer is grounded and called neutral, and there is no center tap.

There should be no power differences unless the 50Hz 60Hz is a problem with a marginal universal motor quality as stated anther poster.

Most normal Universal motor only care about voltage, not frequency....

Does this help you further?

The 90 degree phase difference is irrelevant, except for maybe a very few old systems in the U.S. Except for those (if any are left), 240-volt systems are single-phase with center tap. I doubt that any touchable thing in your vacuum cleaner is connected to either power conductor.

Your vacuum cleaner is double insulated and requires no ground. You can use it in the the US type grid between L1 and L2 where you get 240 Volts.

Unfortunate this is not how they connect main house power outlets. Only one phase is connected in general. And you'll get 120 Volts out of it.

Different is the plug of the washer- dryer where both phases arrive.

When I wired my house, I used some EU outlets with 2 phases to get my european stuff to work. Your other option is a transformer that has primary 120 Volts and secondary 240 volts (some even give you 220 Volts)

These transformers come in versions with a receptacle plug that you need.

I have 2 of these too. BTW there is no 90 degrees phase shift between L1 and L2.

Its always wrong for a user to connect ground and neutral in most of the educated world, only some areas in the USA (I am told!) allow multi ground neutral connections I recently found out on CR4. UGH!!!

In all the countries that I know of power wise, it is expressly forbidden.....but I am sure that it is done elsewhere too, its simply not a good idea to my mind, but that's just me!!....One link only is allowed....

But why would you be worrying, he does not need neutral at all, he only needs to connect both ends of the same phase (it is NOT two phases, it is one center tapped to provide half voltage (120VAC) neutral) and the ground to the correct points.

This neutral, will be usually be linked to ground at some point between the local transformer and the user.....so don't worry!! It should only be done by the electricity supplier...not the end user.

Usually, to provide a greater power/vacuum suction from a light and small motor, the motors in vacuum cleaners are often "Universal", which means that they simply don't care about frequency (they would even run normally on a DC voltage of the same level).......

Naturally I cannot see the motor in this particular machine, but the chances of it NOT being Universal are almost nil!!

I'm not sure what you mean by 'multi ground neutral connections'.

As far as I know, virtually all homes everywhere in the entire USA are supplied from 240V center-tapped transformers, with the center tap grounded. As you say, this is two halves of a single phase, NOT 2 phase. On the other hand, since I commonly measure voltages with respect to ground, I see the two 120V lines as having opposite phases (180°).

I once taught in a classroom where one pair of outlets of a quad outlet box was wired from one phase, and the other pair was wired from the other phase (sure sounds like 2-ohase). Not knowing this detail, I plugged a computer into one outlet, and a printer into another. The instant I plugged the printer data cable into the printer port of the computer, I heard major fireworks, and the logic board of the computer was fried. The isolation capacitors were designed for 120V, not 240...

In modern USA homes and businesses, all 120V outlets are three-pin, with a hot, a neutral, and a ground. Neutral and ground are connected together, either at the outlet (not legal) or at the circuit breaker panel (legal). The actual connection to the earth is at the base of the transformer (a wire coming from the transformer down the pole to a ground rod driven into the earth near the pole, in the above-ground installation at my home).

My home was built in '62. At that time, only outlets near water (kitchen, bath, utility room, outdoor) were required to be 3-wire. All others were, and many still are, 2-wire, with polarized sockets (one flat blade wider than the other). Over the years, I have replaced a number of the 2-wire outlets with grounded 3-wire outlets. Since it would require major construction to actually run a ground wire from the breaker panel to these outlets, I have connected the ground pins to nearby copper water pipes. Thus I definitely do have multiple connections to earth, and do indeed have a potential for ground loops. Fortunately, I'm not aware of any problems due to these installations.

It appears that the USA allows it to be done.

But what you did with your sockets would have been tolerated in say Germany 50 years ago, but to me it is still unsafe, which is why I rewired my house to a full 3 wires for all sockets and other fittings.....and added RCDs to each phase.

But I was not actually referring to the (relatively) low voltages in houses, I was actually talking about the HV supplies BEFORE the house transformer.....not after...

See here for example:-

neutral-single-earthed-or-multi-earthed

There are many references to such methods on the internet....but mostly USA I believe....here it is not allowed.

"The actual connection to the earth is at the base of the transformer"

Be careful. That center tap may be grounded but it is not connected to neutral except at (and only at) the circuit breaker panel. This is done through the bonding screw.

I was once called to a neighbor's house where he had replaced a main disconnect breaker panel. He had neglected to install the bonding screw, so none of his 120 volt appliances were seeing the correct voltage. It didn't take long for me to figure it out, but he popped a few light bulbs and burned up his TV before he'd called me.

Thanks. I've lived in this same house for 44 years, and done quite a few modifications/additions to the electrical system, such as extending the 240V dryer line to the garage to power my milling machine (I later replaced the Chinese 240V motor with a US 120V one, but the 240V is still available if needed.).

I have indeed thought about replacing my breaker panel, but it would be such a big job, I doubt if I will ever do it...

That is in fact 180° apart as its either end of the same phase. US 60Hz.

Where did you "pluck" 90° from???

Perhaps he was trying to describe the 90^o difference in a 2-phase system. Only speculating.

In this situation the two phases are 90^o different from each other.

Good Luck, Old Salt

Rarely used nowadays I believe....

Rarely used but still possibilities. Has anyone definitively and conclusively stated what the OP's system is?

Good Luck, Old Salt

That was it. :)

But who uses 90 degree 2-phase for power disribution?

I thought the standard was three phase (60 degree) run to the area, and then for home use, each house gets assigned two legs of the three-phase (selected to try and balance the load in the area, a third of the houses get legs 1+2, a third get 2+3, a third get 3+1), so each house 'sees' a 240V single phase source, which is then center-tapped at the breaker panel to create two branches of 110V, single phase (where the branches are 180 out of phase with each other, but you never combine the branches after the breaker panel, so it doesn't matter) with the possiblity to supply 220V for 'Major appliances' Such as Electric Stoves, Washer/Dryers, Refrigerators, and A/C units.

Granted, those major appliances have been redesigned over the years to run off 110V AC, 20 Amps (with the newer ones designed for 15 Amp) so the 220V branches are not needed much in the US.

Internationally, I thought power was either 220V split into 110V like in the US, or 220V used without a split, such as in the UK.

"But who uses 90 degree 2-phase for power disribution (sic)?"

I believe at least two earlier posts have answered that question - Philadelphia.

Standard three phase is 120°, not 60°.

I may well be out of touch, but I've never seen a 120V built-in electric range, cooktop, oven, dryer, or A/C. Those are all 240V in my neighborhood.

Thanks, I had my math wrong when working out the phase angles.

And while buil-in units may still use 240VAC, the wall/window units, which used to be 240V, have transitioned to 120V, 15A these days. On older buildings you might still find a 24VAV or a 120V, 20A outlet near a window in Chicago.

360 divided by 3 = 120° between phases.

You are correct and the same is true in the USA under the NEC.

The only connection to the chassis of any electrical device allowed is a separate equipment ground.

You may need to purchase an adapter plug.

A call to the manufacturer service center should answer your concerns.

Dear SHOCKHISCAN

check the OP:

"the plug fits Brazilian outlets"

Europlugs and Brazilian outlets are 100% compatible per IEC standard.

So, no need for an adapter plug.

brgds

Snel

You are assuming that it was not bought in Britain, as they have a completely different plug that is strong on safety and has been around longer than I have!

Some other countries do use them, notably those countries that are or were part of the commonwealth of GB....

Its probably the safest mains plug around.....bar none....

I hope he did buy it in mainland Europe!!! and that it has the small Euro plug, not the big one!!! People here seem to forget that there are two sizes, one with an earth connection and one without!!!

In fact there is a third one I nearly forgot, as big as the big one, but with no earth, it looks like this:-

The big one with earth:-

The small one:-

The French/Thai ones:-

I hope you now understand that any of those plugs could be fitted if mainland Europe, but it could also be one of these from the UK:-

That won't fit either!!!

Big Euro, but I have an adapter for it.

Hi Andy, Babe RuthLess,

all these are European plugs, but the "... Euroroplug (CEE 7/16) is a non-rewirable flat, two-pole domestic AC power plug that must be supplied attached to a power cord. It is designed for voltages up to 250 V and currents up to 2.5 A.[1] It was designed such that it can safely be used in the domestic power sockets of most European countries, except for the BS 1363 system found in Cyprus, Gibraltar, Ireland, Malta and the United Kingdom."

http://en.wikipedia.org/wiki/Europlug

Even the prongs are slightly "eye crossed" to have reliable contacts with older (16 A only) Schuko sockets.

I have overlooked the fact that a vacuum will draw more than a 2.5 A so it will not be delivered with an Europlug. But Babe RuthLess mentioned "a very nice Miele S2, the plug fits Brazilian outlets". Not the plug, but the adapter...

"The sticker says 220 because that's what most people say when they refer to what's actually a 240V circuit - well that and the shop didn't have any 240 stickers, though those do exist and are very common. I might change them someday."

It's not actually 240, it's 127 * 1.732 = 220 V, +/- 10%. So your sticker is right...

abraços

Snel

I sympathize, but a properly installed RCD would have removed most of the danger, but it still hurts, I an say that from personal experience....

I have an RCD (or whatever they are called nowadays!) on each of the 3 phases that come into my house, since a long time ago..... I wouldn't have it any other way.....Each phase is 230VAC to neutral by the way. Germany...

Andy: I don't think a GFCI/RCD would have tripped, as the 24VAC is transformer isolated from a 120V power. And as this is a load to the 120, there was no leakage to ground on the primary side that a RCD would protect.

I was just acting as a load of the 24V back to it's return. Which was the chassis of the condensing unit. The shock point was a terminal of a anti-short cycle timer, that is in series with the contactor 24V coil, and safety pressure switches.

You are right, an RCD would not have helped in that situation....my apologies for the misunderstanding!!

Due to what we were all talking about, I was thinking you were talking about 240VAC...that you had simply forgotten the zero!!

By the way, I was talking about a 240VAC shock that I had!!! 10 times higher than yours I fear!!!

24VAC is rarely fatal!!! I personally do not even feel it normally, but with a wet hand, I might just get a tingle...

As a young man in the RN I also received a 440VAC shock, actually twice in all, while in the RN. The first one didn't hurt as much as the second, because I had drunk my Tot of rum just before the first one. (which was also the reason I got the shock by the way!!). I was sitting on a pipe 5 meters over the engine room plates. If my legs had not been wedged between the pipe and the ship's side, I would have fallen, half conscious, backwards and down, maybe broken my neck, who knows?......

An RN friend of mine fell in a rough sea and accidentally put his right arm across the 3 phases of live 440VAC. He had the burn scars tattooed Red Yellow and Blue.....!!)

The only way I can feel 24VAC with my hands is if there is some kind of break in the skin, such as having a metal sliver poking through it. That has happened to me at least once when there was one strand of wire sticking out from a carelessly made connection.

In a similar manner, I once found one strand of wire poking through the tape (almost) insulating a 480VAC connection. That was definitely more than a tingle...

More commonly, I get a shard of metal stuck in my hand from some part I'm making, and don't realize it's there 'till I touch some point with a voltage known to be so low I would normally not notice.

Very true!!

Using 110VDC in a RN dockyard, you could always baffle the non electrical people by turning the butterfly nuts to tighten the connections with power on, arcing like crazy, with your bare fingers....impressive, but you would actually not feel thing.....

Does anyone know why??? Have a guess.

European plugs ARE polarized, except the German ones. ( can be turned 180 degrees in reference to the receptacle) All the others have a pin (or hole) for the ground.

If it's of European origin the CNE isn't used as far as I know.

No telling these days the EU has taken so many new countries in to the fold.

Are you sure it is a 2-phase system? 2-phase is seldom seen in most countries because: the equipment is much more expensive; the appliances for it are more expensive; and the wiring you are describing sounds, at least to me, like a single phase 120/240 center neutral single phase system. With this arrangement there three wires, usually colored Black (hot 120v-neutral, 240v from that black wire to the other black or red wire), the white neutral wire (120v to either of the black wires, unused for 240v) and the other black or red wire (240v to the other black wire, 120v to either of the black wires). With this arrangement it is relatively simple to change from 120v to 240v.

Europe uses mostly 240v 50Hz and not a 2-phase system. They are fairly rare.

Also Brazil is listed as having a 127v/220v 60 Hz single phase system. This would be almost identical to the USA. If it is truly a single phase system there shouldn't be any insurmountable problems. 60hz supply vs. a 50hz appliance will make the motor rotate 20% faster and perhaps heat up some from the higher rotation effecting mostly mechanical, but some electrical also such as increased power from the motor.

Since the plugs fit each other, both the country of origin and country it is to be used in, it is most likely a single phase unit. Also 2-phase electrical required normally 4 (plus ground) wire system or occasionally a 3 wire system. To have 2-phase source would require either the generator be wired that way or a phase converter used.

These are suggested sources of information:

https://www.google.com/search?q=2+phase+power+in+brazil&sourceid=ie7&rls=com.microsoft:en-US:IE-Address&ie=&oe=&gws_rd=ssl#q=2+phase+power+diagram&rls=com.microsoft:en-US:IE-Address

http://www.worldstandards.eu/electricity/plugs-and-sockets/

http://en.wikipedia.org/wiki/Two-phase_electric_power

http://www.3phasepower.org/2phasesystems.htm

http://en.wikipedia.org/wiki/File:Elementary_Two_Phase_Alternator.jpg

http://www.trade.gov/mas/ian/ecw/br.html

Running a 240v appliance at 120v is not a good thing. The power is reduced by 50%, if not more. Heat will also be a problem.

In the whole USA, only a very small section of Philadelphia, PA, has 2-phase electrical available to them at this time.

I hope this helps you solve your quandary.

Good Luck, Old Salt

I think you are being pessimistic old salt. Here in the Philippines we also are nominally U.S.-style but only the 240V is usually used (with US 120V outlets!). A bit like Brazil.

I have many European/Australian appliances including vacuum cleaners that are quite happy with 60Hz. Most modern vacs have series-wound brush-type motors and are not frequency dependent. If the unit has electronic speed control (a la light dimmer) it might behave less than optimally when not at full speed.

Not pessimistic, going by what information the poster gave and didn't give.

What he was describing as the electrical source didn't nearly fit the description of a 2-phase supply, a very rare configuration in modern times.

240v unit running on 120v is an invitation to junking the appliance. That's only 50% of the required voltage, not a good situation considering heat dissipation. How do we know that the Philippine system is identical to the Brazilian? He doesn't state the country you are referring to is the same situation? Not good for him for us to assume. We may be giving him bad information for what he has, a bum situation.

I know of many 240v motors and units that would not run properly and healthily on 120v or 120v on 60v. A few are my wood lathe, metal lathe, milling machine. table saw, drill press, air compressors, hand drills, battery chargers, pipe threader just to name a few. At this time in life I certainly could not replace all of them just because I listened to someone on a blog that I don't know the validity of their answer. Besides that, the wife wouldn't let me get all of them.

Most 50Hz motors will run on 60Hz but will rotate 20% faster due to the increased frequency. Due to this mechanical components such as bearings may get hotter.

Poster did not state what type of motor the vacuum was equipped with. Most is not good enough, at least to me to assume. How do we know it isn't one of the Other type motors?

You are certainly entitled to think that I am being pessimistic. I think I am being cautious on behalf of the original poster.

Also, the citations given clearly support my statements. Reading them may be informative or reminders to us. They were reminders to me of my previous knowledge hidden in the depths of my memory.

Good Luck, Old Salt

Yep, all good points and I appreciate your caution but let me quote the OP. " My house is wired so that I have both 120V and 240V outlets... So here's the $300 question: will I fry or slowly destroy this nice vac if I plug it in my 240V, 60Hz, two-phase outlet?"

Here the "2-phase" refers to the (incorrect but common) way of describing the US split single-phase 120-0-120 system, rather than 2 phases of 120V at 120 degrees. If I am wrong then I hope someone will correct me about the supply in Rio.

Anyway, if he plugs it into a supply of 240V 60Hz as mentioned there should be no problem even if it uses an induction motor as it will have sufficient additional voltage to reach the required RPM.

Theoretically, some motors, usually single phase 60Hz induction motors, do not like to be used on 50HZ. Though nowadays most are wound to accept either and are then so marked.

Usually, other than the speed difference, a 50HZ induction motor will run on 60Hz OK.....

Universal motors are not frequency sensitive.

Home type vacuum cleaners are generally Universal type motors....loud, powerful and cheap....nowadays they get junked when the motor needs new brushes....sadly!!

>>>Also Brazil is listed as having a 127v/220v 60 Hz single phase system. This would be almost identical to the USA. If it is truly a single phase system there shouldn't be any insurmountable problems. 60hz supply vs. a 50hz appliance will make the motor rotate 20% faster and perhaps heat up some from the higher rotation effecting mostly mechanical, but some electrical also such as increased power from the motor.<<<<

Hi Old Salt, Your Brazil example is completely different from the US residential net.

When 127/220 Volts is listed, that means that there is a 3 phase system as source:

Wye or Star as it is called. The 127 is derived between neutral and 1 phase.

(127 *1.73 = 220 volts)

Some of your points I simply do not agree with.

Firstly, universal motors are speed sensitive to the applied voltage, not to the frequency, so it should turn at approximately the same speed....

Induction motors are frequency sensitive as you mentioned. Seldom used in home vacuums I feel....synchronous motors are also frequency sensitive.....there are some others too we do not need to mention.

If we agree that the US and Brazil have similar mains supplies, then the lower voltage is generally achieved with a step down transformer, center tapped to provide a neutral for either phase end.....the same transformer also supplies both ends of the same phase for the higher voltage.

The primary of the transformer could be connected to a HV transmission line via a single HV phase of a 3 phase system, probably Delta......though I have to admit its a long time since I looked.....

Have a great day!

Thank you. Is your answer for my post? I do not see the relevance of your answer to my post. A 127/220 Volts net is not similar to the US residential 120/240 Volts.

I cannot recall me talking about speed and/or frequency relative to this post.

Best regards. D

I see a strong similarity myself....we all know that values are nominal and so they picked a slightly different nominal value. Big deal!!

Here in Germany it is nominally 240VAC, but I usually measure on either one of two good quality meters, around 220VAC....Which simply means that I live farther away from the power station/step down transformer/on a heavily loaded transformer.....or whatever.....

Your comment:-

When 127/220 Volts is listed, that means that there is a 3 phase system as source:

Is not really needed, as generally, the world over, a 3 phase system is used.....no matter what the final voltage or what the frequency.....and has as good as nothing to do with the voltage that reaches a house for example.....

Look here for a reasonable explanation:-

Electricity_generation

Where you will find this simple but accurate diagram that probably applies to most electricity generation world wide:-

Also, you did not make it FULLY clear, that you were quoting another CR4 member, (who also agrees that the supplies are similar by the way!!).....therefore it looked like YOU were saying that motors changed speed with frequency.....I personally find that its better to put the quote from another member for example, up front, something like:-

Our dear member XXXXXX wrote the following:- "and put it in quotes as well"...

Its your choice as to whether you want to be fully understood accurately or not......that was just a suggestion....there are other maybe better ways......

American residential power is 120 - N- 120. To operate a 230-240V appliance on American power, have an electrician connect a single phase, 240V plug the cord and simply connect the appliance to the 240V outlet. To operate a 120V appliance, follow the same procedure except for 120V. 50 Hz appliance connected to 60Hz power will have a higher reactance (Z = AC Resistance) therefore will not run as efficiently because the apparent power will be less. You will not burn up the appliance but it wont work as well.

According to the USA Dept of Commerce, International Trade Commission,

http://www.trade.gov/mas/ian/ecw/br.html

Brazil has at least ELEVEN different combinations of nominal voltages, phases, frequency, and frequency stability!

Do we have sufficient correct information to make the statements we are? How much are we assuming (ass-u-me) based on possibilities and not facts? Are we really answering the originator's question? Are we possibly going on our own assumptions, answering based on them, posting these, baffling the OP and probably ourselves?

Should we be getting more and better facts so that we can give more applicable and accurate answers? Good Questions bring Good Answers, Bad Questions bring Bad Answers. We probably all think we are giving the best answer to the question. Do we really have enough correct information to give a good answer?

Just a thought.

Good Luck, Old Salt

Thank you for all your replies, I'm actually surprised my question started a long (and rich) discussion.

I think an apology and quite a few corrections are in order to clarify my original question. I think I used many wrong terms here, not being from an engineering background and not researching enough before asking.

So first of all, let me replace "phase" by "hot" or "live" wire. There may well be eleven different combinations of nominal voltages, phases, frequency, and frequency stability in Brazil (most likely in industrial settings from various times), as old salt mentions, but I don't know enough to comment on any but the two common residential types we have here: US-style 120V 60Hz and our own 240V 60Hz. Those two types of installations have, for each outlet, a hot wire, which I mistakenly called "phase"; a ground wire; and a neutral wire.

In Rio, if I put a voltmeter to most of my place's mains outlets, I get 123V from hot to neutral and from hot to ground. In, say, Brasília or Recife, if I do the same I'll get 240-ish V hot to neutral or hot to ground.

Now, in Rio, São Paulo and other 120V regions, you can ask the power company and your electrician to wire 240V outlets whose two "hot" wires give 120V to ground and 240V between each other.

All of this in 60Hz.

I have to pay a little extra to the power company every month in order to have those 240V outlets; I recently renovated my flat and had to change the meter, the circuit box and all the wiring in order to able to do that. The reason was I wanted to get rid of my gas connection (very small, very old flat, not enough ventilation) and install electric water heating and an induction cooktop. Those things can only be found in 240V form in Brazil. Since I was paying extra for the privilege, I thought I might as well have other 220V outlets. That'd allow me to import items cheaply from Europe and China, plus I have family in parts of the country that use 240V and there have been a few instances of equipment like hair dryers not working etc.

So that's the background. I stand corrected and apologize for my imprecisions. Hope this helps.

Now, about the vacuum, from what I've seen on Google images the motors have 120V or 240V on their labels, but no mention of frequency. I'm assuming that's because Miele uses universal motors, as I think dvmdsc said (sorry, can't go back to the thread right now). So things are looking up for me, right? :-)

Should I expect a loss in performance anyway, for the Euro Miele, compared to using a 120V model? I think that's my main question, loss of performance and durability in this context.

And now one more thing (sorry, as I said I'm no engineer so please bear with me!): I noticed from the specs that the Miele S2 sold in the US, for 120V systems, has a 1200W motor whereas this 240V model has a 1600W unit. The US model is capable of 141 CFM (cu. ft. / min), which works out at about 66 Litres / sec. Miele Europe states that the 1600W, 240V S2 is capable of sucking 43 L / s.

I assume there's a difference in current being fed to each motor (120V taking 10A vs. 240V taking in 6.6A), which may explain the difference in performance; or it may just be that US and Europe measure vacuum performance differently (considering the hose or not, for instance). Anyone care to comment?

Again, may thanks for your inputs, your interest and your patience. I feel I came to the right place to ask those questions. :-)

Thanks for getting back to us! Many don't... You clearly underestimate yourself; you came up correctly with the 6.6Amps for your 240V Vac. Some questioners here could not!

When you say US-style, does that mean you have the same outlets?

Surely the 240V outlets are different! We have several different styles of 240V outlets, generally only used for higher power devices like water heaters, driers, many cooking devices, etc.

Actually, you can, in most browsers at least, get back to the original thread simply by clicking the Left-Arrow to the left of the address. Once there, a Right-Arrow should appear, to go back to your reply once you've seen what you needed to see.

Your math is also correct converting 141CFM to 66 l/s. It is indeed a bit strange that the higher powered unit has a lower rated flow, but there are many possible explanations. One that occurred to me would be noise suppression. Vacuum cleaners, like many devices powered by high speed universal motors, are notoriously noisy. Reducing the noise will almost certainly reduce the flow. In fact that noise is the main reason I installed a built-in vacuum cleaner; the noise is out in the garage. I can vacuum most of the house while my wife is asleep without waking her!

*many thanks (typo)

Great post, thanks. I actually felt that you did quite a good job with the original post, but now you have qualified that info further....thanks.

You also cleared up the sticky question that some may have had here as to the compatibility with the USA electrical system.

I can safely say that where you live its as good as totally USA compatible....I see no difference whatsoever...

Your questions may have already been answered already today, so I will read down the list before answering anything else.

I always read from the top down....slowly!!

I think DKW probably answered your question best as it would appear that the higher voltage machine not only has a lower "suck", but may also be MUCH quieter than the other....its certainly a different spec for some reason other than just voltage....

No other explanation that I can think of better explains the differences......but thats just me, maybe someone else knows better!

Right, I had a few photos of some of my actual outlets because they weren't aligned and I had to send an e-mail complaint to the builders (who have yet to correct this, and I'll probably just let go).

They're standard Brazilian outlets, you can't buy anything else here, these are mandatory:

These are 127V outlets in two versions, 10A and 20A (the one with slightly larger holes). The 20A outlet is for my Nespresso machine, which comes with a thicker plug to match - and prevent it from being used on "lesser" outlets. (BTW you can see the trims don't align, irritatingly. The right-hand-side trim is just an access door to some wiring, but it should be aligned, my outlets are all crooked or misaligned... D*mn builders... Oh well. That was an off-topic rant. Sorry.)

Here's a 220V outlet, I picked a different color (red) and put "220 Volts" stickers to make sure no-one uses a 120V appliance with those:

That's it. They look the same and it was my choice to clearly mark the 240V outlets in red. I could've just used the stickers (you need to identify different voltages or the utility won't accept your installation). The sticker says 220 because that's what most people say when they refer to what's actually a 240V circuit - well that and the shop didn't have any 240 stickers, though those do exist and are very common. I might change them someday.

Hope this helps you guys help me. :-)

WOW! so a 120V plug will physically fit a 220V outlet!? That's absolutely incredible! You were very wise choosing the red outlets for the 220V locations.

I have to believe that an awful lot of 120V devices get destroyed by being plugged in to 220V outlets.

The same occurs here with regard to the rated vs. actual voltage. You will hear people talk about 110V, 115V, 117V, and 120V appliances. All plug in to the same standard outlet.

In practice, homes are usually pretty close to 120V. Mine is 122.1-122.3V this evening, dropping to about 120.5V when the A/C comes on. Of course the A/C uses 240V, but I'm measuring at the same 120V outlet either way. It's been hot today, (97°F, 36°C) and the A/C is still coming on periodically at 9:30PM.

For a variety of reasons, I see a lot more variation in the '120V' outlet voltage measured in industrial settings. Anything from 105V to 130V can be found at various locations within our plant. A couple of years ago, I had to rewire an outlet where an ignorant electrician had connected the 'stinger' of a 240V Delta transformer, leaving 190V on that '120V' outlet. They burned out 3 coffee makers and a microwave oven before they asked me to investigate.

I have to ask, how is 190VAC achieved by a dumb electrician in the USA?Thanks in advance.

A picture in return to give you an answer

Yep! You got it. The 190 was a round number from memory. I don't recall whether that transformer was heavily loaded, had a low input voltage, or what else... It may have been over 200.

In any case the electrician connected the 120V outlet between X0 and X1, instead of X0 and either X2 or X3. The 208V is indeed the correct theoretical value.

Very interesting, many thanks for posting.

It appears that there are dangers associated with this old fashioned system (according to various websites). Special markings are needed to follow code.

Its disadvantages out weight the advantages nowadays it would appear...

Loading on the mains 3 phases is also unequal, which is probably why Neutral current should be limited to a max of 5% of transformer output.

Basically, an old "quick & dirty" method.....which I never ever saw used in the UK or here in Germany......

One way the USA has avoided some of your quandary is by having approximately 150 different plug/socket possibilities. There are generally a different plug/socket configuration based on the different voltage(s), different current ratings, grounded or ungrounded and different categories of types. A few of the categories are: straight blade, twist lock, IEC, explosion proof, etc.

For instance the choice for the 120v, 15amp,:include: grounded or ungrounded; straight blade; non-polarized or polarized; twist-lock; explosion proof; and IEC among several options.

This is all done mostly to prevent the cross connection of different type plugs/sockets being connected. This mostly true but some types can be forcibly be altered to connect with a different type plug or socket. For example a 120v 15amp twist lock plug can be forcibly be widened to fit a 20amp socket. I'm not endorsing this but know it has been done.

Charts of some of the different types are:

http://www.stayonline.com/reference-nema-straight-blade.aspx

http://www.stayonline.com/reference-nema-locking.aspx

As you can see there are many configurations to prevent cross connection of different ratings.

Hope this helps your understanding the various types and the need for them.

Good Luck, Old Salt

Interesting! The outlet style is similar to one of the Swiss designs. I still have one on a device I wired for use at a TV Symposium exhibition in Switzerland 20 years ago. If you remove the center pin (ground) it will mate with the regular Schuko outlet.

As for mixing 120V and 240V in similar style outlets, that is very common in S.E. Asia. where 120V U.S. outlets (parallel blades) are routinely used with 240V because the governments lack the incentive to force the adoption of proper International standards. An exception is S. Korea where they have both voltages using U.S.-style for 120V and Schuko for 240V (actually nearer 115V and 230V). I have used that system in my own home.

The 10A rating for the 120V version of the vacuum cleaner is probably due to the need to limit the current whereas that is not needed on the 240V version so a nominally higher power is practical.

It is a good start that you mark the outlets. I hope you are awake enough all the time and that you concentrate about it.

It happened to me a few times that power drills got destroyed in de wrong receptacle. When you live alone the chances are better,

I simply replaced the regular outlets with a different, not interchangeable type.

I haven't destroyed anything yet, but I just moved in (April). Give me time. :P

I'm a bit confused with all the answers to be honest, so let's sum up the info we've got so far. Please correct my assumptions as you see fit:

1. It's safe to assume that the 240V European Miele vacuum will work as intended on my U.S.-type 240V supply, which uses two "hot" wires. That includes the control electronics.

2. It's also safe to assume that the vacuum uses a universal motor and that both the motor and the control electronics won't be affected by the fact that my electric supply is 60Hz.

3. There won't be any significant loss in performance from operating this thing in my system.

4. Any stated differences in performance between US and Euro Miele products is probably due to different regulatory requirements (eg. noise limits, max. current draw, different ways of measuring flow etc.) rather than different voltage/current and frequency specs.

If what I'm assuming is correct, then I'll keep my Euro-spec vacuum and save myself a pretty penny. If not I'll just bite the bullet and exchange it for a proper 120V model.

Thanks again!

Hi Babe RuthLess,

I live in Brazil and have used many appliances including vacuum cleaners intended for 230 V (standard European) voltage on 220 V as derived from 2 hot 127 V wires.

Agree with all your 4 points.

No need to exchange your vacuum. It will not be damaged in case someone plugs it to a 127-V outlet.

brgds

Snel

I like your summing up!