3 Phase Supply Voltage Problem (Russia)

[kjedwards]

Hi, my wife and I are over in Russia where we have an almost completed house. We have a 220V 3 phase supply. Recently we have experienced some electrical problems, mainly related to low power - dim lights, etc.

I measured the voltages we are receiving at our house, which are -

Phase 1 : 182V
Phase 2 : 183V
Phase 3 : 165V

I then went to our electrical companies local supply station (where our electrical meter is located). I measured the voltages on the electrical companies side of the box, these are the same ie -

Phase 1 : 182V
Phase 2 : 183V
Phase 3 : 165V

I am completely stuck! Anyone have any ideas what can be causing the low and unbalanced voltages?

Thanks

 

[plugsandsparks]

Hi, when i look up Russia 3 phase, it is stating 220V single phase and 380V 3 phase. When you measured the voltages, are you measuring between phases or are these readings between phase and neutral / earth ?
Between phase readings are stated like this Phase 1 - Phase 2 V, Phase 2 - Phase 3V and Phase 3 - Phase 1.
Readings to neutral or earth are stated like this Phase 1 - N, Phase 2 - N , Phase 3 to Neutral.

So if your readings are between Phase and Neutral , then yes that is a significant reduced voltage and if your equipment. In this country we would simply call the local supply company and report it.
Hope this helps

 

[Silly Sausage]

ELECTRICITY: Russia's power grid, held together with spit and grit - https://www.eenews.net/stories/1060010742

Sounds like you're lucky to get any kind of supply at all!

 

[Pete999]

220 volts in Russia are derived from utilizing 2 phases, so you just see 220V at sockets etc, makes it somewhat difficult when testing (Live) and safe isolation, remember 2 phases equal DP fusing.
In some cases though, and I'm not that sure of how they do it the manage to bring Land N into a property, whenever I contacted the UPDK sort of Russian supply Authority, they became very cagey, as if it was a State Secret, so at times it cost me some cheap Voltage indicators from Finland to get any work done, and as I didn't speak Russian that well, I never did get much info, by the way this was back in the Cold War era, things may have changed somewhat.

 

[kjedwards]

Thanks plugsandsparks, all readings were taken Phase-Neutral. We will need to contact the supply company and see what they say.

 

[Pete999]

Thanks plugsandsparks, all readings were taken Phase-Neutral. We will need to contact the supply company and see what they say.

"Niet Problemo" more than likely Tovarich

 

[static zap]

Any appreciable N-E voltage -- (earth stake !)
to give a clue (phase 3 sagging as neutral lifts ? )
(heavy un-balanced load on phase 3- Turned off over xmas ?)
(if not so , sounds like a "local feature")
..Could be a local strategy to limit demand on
phase 3 if it has a weakness
-- All Speculation --

 

[kjedwards]

Could be a local strategy to limit demand

Highly likely!!

 

[Pete999]

Highly likely!!

An idiosyncrasy of Local distribution methods, is the most logical answer.

 

[Lucien Nunes]

If he's getting 173V-ish on average L-N at the moment the corresponding voltage L-L would be 300V. So I don't think that supply is supposed to be 220V L-L, just a regular 3P+N 220/380V service. Even in the 90s that was all I saw there, albeit at large sites not domestic, although I'm sure you're right about the older 220V supplies having sometimes been L-L from 3-phase delta.

I think the voltage is low and unbalanced because it's broken. Maybe someone can be remunerated to fix it.

 

[plugsandsparks]

Whats the going rate in Ltrs of Smirnoff, is this a 1 litre problem or a 5 litre problem........

 

[Midwest]

Happy New Year You filthy Animals

 

[kjedwards]

I think the voltage is low and unbalanced because it's broken. Maybe someone can be remunerated to fix it.

I measured the voltages on the electrical companies side of the box. If the problem is their side, they pay (in theory) if our side, then we pay. Is there any way I can check to make absolutely sure which side the problem is?

 

[marconi]

Re #13: Over a week:

a. With your Main Switch Off measure the phase voltages at the input to the meter, the output of the meter and at the input to your Main Switch at say 0800, 1200, 1600 and 2000.

b. Now turn on the Main Switch and load up your supply by the same amount (say 40-50A) each time and measure the same voltages as in a) at 0800, 1200, 1600 and 2000.

Plot these on some graph paper. If the spacings between the voltage readings at the suggested times remains constant over the week then there is no variation in the impedance of the supply up to your Main Switch input.

Consider the volt drop between the meter and Main Switch - is it reasonable for Russian wiring and the cable size between meter and Main Switch and constant between MS Off and MS On with load.

What do you observe for the phase voltages at the input and output of the meter? Any variation over a day or a week?

You may now have some evidence to show the fault lies beyond your property in the supply network. If it is a constant low supply voltage or a varying supply voltage is also useful to know. The former indicates something permanent - eg HV/LV transformer winding volt taps or a 24/7 large load sharing the same part of the LV network as you - whereas the latter could also include some poor connections or inadequate network cable sizes.

 

[kjedwards]

Thanks Marconi. I'll give it a try.