European Voltages 3

[steve5352]

I have a customer in Great Britian having difficulty. The motor is a US made, 240V ( Hot, Hot, Ground ) single phase model.
Could the european 222V ( Hot, Neutral,Ground ) service prevent it from running ?

 

[sreid]

The motor should at least run on 220-230 VAC. Is the motor supplied with a US color coded AC line cord? The UK color coding is different and they may have power and ground leads reversed.

 

[SteveKW]

The lower voltage AND lower frequency will be very hard on that motor if it is running close to it's rated HP. That motors HP should be derated because of those two factors!

What is the driven load?
What is the nameplate information?

An old timer that used to work here also had a trick of bending open the springs on the centrifugal switch to make it operate a bit earlier with the new frequency. This was done by bending open or wedging open, with a screwdriver, a coil or two of the two springs.

 

[jbartos]

Suggestion: If cost is not the major factor, the motor might be replaced by the 220V single phase motor or a suitable AC-AC converter or motor drive provided.
Visit

http://www.thomasregister.com

and type AC-AC converter
or
type Drives: Motor under Product or Service, which will return 54 converter companies or 169 "Drives: Motor" companies to approach to

 

[ScottyUK]

British voltage is still 240V as it has been for many years. The Europe-wide standard is 230V, but with very wide tolerances to accomodate Britain with 240V and the rest of Europe with 220V. Over time this situation will probably change, but given the long life of distribution plant it is likely to stay this way for the foreseeable future.

The lower frequency will obviously make the motor run at a slower speed, and the cooling fan will be less effective. Therefore derate the motor to accomodate this.

What is the nature of the problem your customer has?



-----------------------------------

Start each new day with a smile.

Get it over with.

 

[ScottyUK]

jB,

Is an "AC/AC converter" the piece of equipment the rest of us know as a transformer?




-----------------------------------

Start each new day with a smile.

Get it over with.

 

[rbulsara]

Use of a buck/boost (auto trasfromer) to boost the voltage from 222 to 240 (or anything greater than 230), can also be considered for small single phase loads.

This however will not address any issues with 50hz vs 60 hz, but eliminates one (voltage) issue.

 

[aolalde]

After identification of the terminal leads is done, you should consider:

The change from 60 HZ to 50 HZ will reduce the winding reactance and probably the magnetic circuit will be saturated, demanding very high magnetizing current. That could burn the windings in short time.

By the other hand, if the motor has a centrifugal switch to disconnect the starting circuit it could never open at 83% of the speed ( 50/60). Sustained high starting current could burn the windings too.

Regularly a 60 HZ motor has to be redesigned and rebuild to work properly at 50 HZ.

 

[jbartos]

Comment on ScottyUK (Electrical) Apr 2, 2004 marked ///\\jB,
Is an "AC/AC converter" the piece of equipment the rest of us know as a transformer?
///Yes, an AC/AC converter may include a transformer. However, the Thomas Register has a separate category for transformers, which makes the transformer manufacturers be more visible.
Essentially what I meant was:
The AC-AC converter can be a frequency converter from 50Hz to 60Hz. It might potentially be AC-DC-AC. That is why I indicated suitable AC-AC converter.
AC-DC-AC converters are sometimes incorrectly abbreviated to AC-AC if the input and output are considered only. However, there are true electronic AC-AC converters, e.g. Matrix Converters.\\

 

[constable]

I think that one or two of our subscribers have got some wrong information.
The standard voltage that is now accepted throughout the UK is 230 (two hundred and thirty) volts and this was put out by public announcement from the Central Elecricity Generating Board about four years ago.
This is endorsed by the IEE in all of their publications from the date of the countrywide change.

Constable
DART Aviation Systems

 

[jbartos]

Comment: The central Europe tends to have 380V/220V system. 220V is often seen as an option on many electronic products, e.g. computers, dryers, raios, TV, etc.

 

[Skogsgurra]

jb,

380/220 V was long time ago. Voltages are now "harmonised" throughout the European community. This means that 220 V countries have increased their single-phase voltage to 230 V and 240 V countries (mainly UK and Ireland) have decreased their voltages to 230 V. The phase-phase voltages are now 400 V.

 

[jbartos]

Comment on the previous posting: Please, would you evidence what you are writing about?
Meanwhile, visit

http://www.exhibitineurope.com/voltages.htm

for Central Europe voltages
e.g.
220V:
Hungary
Czech Republic
Poland
Yugoslavia
Slovakia
Slovenia
Liechtenstein
Latvia
Lithuania
Estonia
Greenland
Iceland
etc.
In case that you exhibit in the above countries, you better be prepared or equipped for the 380V/220V in the above mentioned Countries

 

[Skogsgurra]

jb,

steve explicitly asked about the UK. Not central Europe.

snip; "I have a customer in Great Britian having difficulty"


The list you are referring to seems to be somewhat outdated. It says that the UK has 240 V - which is not true. Many of the countries mentioned are now members of the EU. Anyhow, the question was about the UK, wasn't it?

 

[jbartos]

Comment on the previous posting: There is also a following question in the original posting:
"Could the european 222V ( Hot, Neutral,Ground ) service prevent it from running ?"
In fact, the European 220V is often hot and neutral and no ground. The neutral is grounded instead. The receptacle has the neutral connected to the ground pin. The neutral serves as the ground wire.
The electrical stresses on winding will be somewhat different when it comes to the grounded neutral and hot power supply. The electrical stresses on the insulation will actually be smaller.

 

[CJFlatters]

Both Scotty and Constable are correct. The declaration stated that the official European voltage is 400V, but the voltage tolerance stated is +10%/-6%, ie 376 - 440V which embraces all the voltages.

Thus all equipment specified should be be suitable for use on the harmonised voltage.






_______________________________________
Regards -

Colin J Flatters
Consulting Engineer & Project Manager

 

[jbartos]

Comment: Fortunately, more and more loads; especially electronics loads, tend to have a wider input voltage window. This makes the product more suitable to meet the European Harmonized Voltage.

 

[ScottyUK]

Hi Constable -

The CEGB four years ago - that's about fifteen years after the CEGB was broken up, destroying a world-class organisation and giving us the mess we currently suffer! The Electricity Association quite probably made the announcement.

I agree with your date of about four years ago for the announcement of the change, but unless you are served by a recently installed distribution transformer you will still see 240V in your home and 415V in your works. The utilities simply can't afford to replace all the old transformers because of a decision made in Brussels, and the lower voltage is beyond the tapping range of many existing transformers. As they are replaced through old age or through failure, the replacements will be designed for the harmonised voltage of 230/400V.



-----------------------------------

Start each new day with a smile.

Get it over with.

 

[bhalfweeg]

You guys onshore have no idea, in offshore you get all sorts of voltage/frequency combinations and earthing arrangements. Through a process of design by committee we ended up with a 60 Hz system with 11 kV, 6.6 kV, 440/254 V, 230 V (UPS) and 110(55-0-55) V. We started with a 50 Hz system with 11 kV, 6.6 kV and 400/230 V until the Canadian client and tiffies stepped in.

 

[peebee]

Here's some more thoughts to help muddy things up:

240 is not a standard voltage for a US motor. 240 is a standard nominal US distribution voltage, but utilization loads, like motors, are usually rated at 220 to account for voltage drop. (same goes for 120 -- that's a standard nominal US distribution voltage, but utilization equipment is usually rated at 110 or 115 volts). Can you verify the voltage rating of the motor is truely 240?

208-volt distribution is also very common here. And I've often successfully run 220 volt motors on 208, no problem, and nothing special on the installation -- EXCEPT -- these were typically industrial-grade 1.15 service factors motors, TEFC (totally-enclosed fan-cooled), premium efficiency. You might not get such pleasant results with lesser-grade motors.

50 vs 60 hz would seem to be your #1 concern. Lots of information on derating 60 hz motors to 50 hz operation is available elsewhere here on eng-tips.

Interesting notes about the European voltage changes, I hadn't heard of that before. Every GB installation I've ever seen has been 415/240 -- although admittedly they have all been 10+ year old facilities.