Voltage optimisers and lighting

[Engineer54]

Maybe i'm missing something here, but all that unit seems to be, is a straight transformer rather than a regulated voltage optimisation unit!! I'd want to see far better output regulation than what's being shown here. If the whole idea is to optimise voltage to 380/220 V then that's what i'd want to be seeing on the output.... The optimisation units that i've had a look at on the Web have a wide'ish tolerance of the input voltage. that can still output a regulated 380/220 V with a very small +/- tolerance.

As for the lower than normal/expected voltage (optimised voltage) at the lighting fittings, this could well be down to the cable size used and the length of circuits involved. Which is always going to be a factor when retrofitting a voltage optimisation unit into an existing installation.

 

[Knobhead]

I notice on the optimiser it states 3Ph 3Wire not four wire. Where’s the neutral coming from for the output?

If the neutral has been simply linked across from the incoming there will be all kinds of problems with voltage imbalance.

 

[Engineer54]

I notice on the optimiser it states 3Ph 3Wire not four wire. Where’s the neutral coming from for the output?

If the neutral has been simply linked across from the incoming there will be all kinds of problems with voltage imbalance.

Yep i was going to mention that myself... but the post kept posting up. before i was finished writing!! As was also going to advise getting back to the manufacturers. Really need a schematic drawing and a working data sheet (cant think of the correct name?? lol!!)

 

[Knobhead]

An interesting read, I found the technical data sheet.

• An unreferenced star output.
• Tertiary delta winding for harmonic filtration.
• From what I can make out Fixed input taps.

It’s just a Y∆Y transformer with no active voltage regulation I can see. Had it been a Y autotransformer then the star point would be referenced.

No wonder it’s causing problems. I would only use it for balanced 3Ph loads. I wouldn’t be keen on it then due to problems of L→N faults.

The problem with YY transformers is they are virtually transparent to harmonics hence the tertiary winding.

 

[Knobhead]

Just found the same company make a plus range with dynamic switching for on load tap changing.

Doesn’t look like this baby is the plus model.

 

[Knobhead]

From the schematics I’ve found I don’t think these are intended for Ph&N use.

To my surprise it is a Y autotransformer with a high impedance part of the winding reversed to form an artificial star point.

With the tertiary, nine windings in total.

 

[Sintra]

Anything with a CE mark on it made from 1990 can be run on 220V. If the voltage is below this, it is automatically is going against manufacturers instructions!

Basically the Optimisers are a big dimmer switch, and they always work without any problems lol.

As said above, get the lighting circuits off the Optimisers. End of re-lamping every week. Good luck Sintra.

Not easy to get the lighting off the optimisers lol. Optimisers are in switch rooms feeding directly into a 400A panel. Then from this panel the sub main circuits are taken to local dist boards.

 

[Sintra]

As for the lower than normal/expected voltage (optimised voltage) at the lighting fittings, this could well be down to the cable size used and the length of circuits involved. Which is always going to be a factor when retrofitting a voltage optimisation unit into an existing installation.

I have to agree that I don't think any thought has gone into the installation of these "optimisers". All final circuits have been properly designed and installed and as I say no issues up until these where fitted.

 

[Sintra]

From the schematics I’ve found I don’t think these are intended for Ph&N use.

To my surprise it is a Y autotransformer with a high impedance part of the winding reversed to form an artificial star point.

With the tertiary, nine windings in total.

Thanks Tony for your input. At least I can go back to the client with something a little more concrete than my original thoughts.

 

[Knobhead]

Will do a drawing for you this evening.

So much for these being modern technology, I found the same thing in a 1930’s text book.