Operating 380V equipment on 400V supply

[khanvessel]

Hi there,

Is it safe to operate a 3 phase 380V,50Hz equipmment (including motor, UV dryers, PLC and some other auxiliary items) on 400V,50Hz supply? Similarly 220V,50Hz on 230V, 50Hz (single Ph)?

Regards

 

[Parchie]

I believe those voltages are now harmonized in Western Europe and classified as the 400V class. You can use a 380V equipment on a 400V system with confidence. Take note it's just a little over 5% of the voltage and most motor should be happy with that.

 

[khanvessel]

Thanks Parchie,

Same is for other auxiliary items as well such as UV dryers PLC etc? Can I use an auto-transformer?

 

[Skogsgurra]

The 400 V were more or less a rule in the "380" V world for many years. It is only lately (relatively) that newer equipment are rated 400 V. There are still lots and lots of 380 V equipment that now run on 400 V.

Incandescent lamps are usually the ones that die first. But the ones you buy today are rated for the higher voltage (230 V instead of 220 V).

You may experience a reduced power factor in motors and probably also a somewhat higer magnetizing current in transformers. Plus, occasionally, more inrush current. Asynchronous motors will run slightly "better" because the slip is reduced, so efficiency could improve somewhat.

All this is what we have lived with - and still live with. Not a big problem.

Gunnar Englund

http://www.gke.org

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Half full - Half empty? I don't mind. It's what in it that counts.

 

[jraef]

Yes, the "nominal voltage" concept is generally universal, because when designing a machine or system, the engineer involved will (should) know that no two distribution systems will be exactly the same, there is always a tolerance, usually of +-10% minimum. In general if a piece of equipment requires better than that level of tolerance, it will (should) be labeled as such so that the user can make appropriate adjustments.

So no, I doubt you need an autotransformer.

"Will work for (the memory of) salami"

 

[ScottyUK]

It's a bit more complex in Europe where there are still legacy systems running at 380V and 415V, but both are now nominally 400V. 380V equipment has a hard life on a 415V system and overheats because of magnetic saturation. 415V motors on a 380V system overheat because of abnormally high slip. The older gear wasn't designed with sufficient margins to operate over the full European post-harmonisation voltage range, so caution is needed moving legacy equipment to new locations.

 

[Skogsgurra]

Scotty, we have discussed this before. I say that Europe IS 400 V. I know that you have found a few places where someone didn't bother to go down to 400, but I have been travelling from Scandinavia to Slovenia to Spain and the Neherlands. Staying in most countries in-between (Germany, Austria, Italy, France, Belgium). I worked in Norway two weeks ago - and even if Norway didn't join EU - they now have 400 V. I see 400 V (or 230 V) everywhere. I will do Denmark, Germany and the Netherlands next week. I bring a full set of instruments in my van (voltmeter and scope among other things), so I shall continue my "research". Stand by for another dull report.

I did a paper mill in the Lake District (Beetham) and I am a bit ashamed that I didn't check the mains voltage. I should've.

Gunnar Englund

http://www.gke.org

--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.

 

[ScottyUK]

Hi Gunnar,

The UK was always the odd one out in Europe using 415V.

It would be interesting to see how well the change has been implemented. I'd also be interested to see how many private network operators in the UK have made the effort to drop voltages. We've recently built three new substations and they're all 400V, but that effectively makes us a dual-voltage site because of the voltage ranges stated on the hazardous area certification for our motors.

I wonder if Marmite knows what the British utilities have been doing post-harmonisation?

 

[Skogsgurra]

Marmite - that's beyond comprehension. And I doubt if any standards apply.

Good to hear (see, actually) that EU had some impact. But I'm not so sure it will last. I guess there are tap-changers to be used after you leave the EU again

Gunnar Englund

http://www.gke.org

--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.

 

[ScottyUK]

LOL. Member Marmite works for one of the DNO's. And the brown yeast-based substance is fantastic.

Off-circuit tap selectors have a reputation for causing problems if a tap position is changed after many years in service. I have never seen such problems first-hand, but people are cautious and rightly so.

Are you expecting us to leave the Eurocracy? Germany will have to bankroll the French and Spanish economies on its own!

 

[Skogsgurra]

I heard about the Scots. And someone said the the English should do a similar thing - only better!

Sorry, didn't know about member Marmite. But, do not be surprised, I use Marmite when preparing some dishes. Onion soup and some mushroom soups benefit from some Marmite and some Xerez.

Gunnar Englund

http://www.gke.org

--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.

 

[ScottyUK]

There's a secret plan to give the Scots independence, then we're gonna invade and steal all the oil for England. But don't tell anyone.

 

[sibeen]

In Australia our voltages were 'harmonised' to the European standard of 230/400 volts. In reality it just meant that the standard was changed with a higher percentage value on the upper figure, so for voltages below 1 kV the standard nominal voltage steady state is +10% -6%.

If you throw your voltmeter into any standard GPO you'll see a nice clean 240 volts.

BTW, Vegemite is a far superior product

 

[waross]

The short answer is that the equipment will work.
The longer answer is that there may be issues with some equipment if the utility voltage tends to be at the high end of the tolerance from time to time. This is an issue with long rural distribution lines, not so much in built up areas.
I worked in one area where the local utility would provide me with a floppy disk with a download from the electronic billing meter of the history of the past few months recorded at 15 minute intervals.
You may wish to attach a voltage recorder to the service for a week or so. If you see voltage peaks that may affect some of your equipment you may consider installing an auto-transformer for some or all of the equipment.
In the majority of instances, with a stable utility voltage, there should be not issues.

Bill
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"Why not the best?"
Jimmy Carter