Low Voltage problem What type PLC use?

is it a stable 208VAC? or does if fluctuate between 220VAC and 208VAC? This is important. First, call the local utility and complain loudly so that they will do something about the low voltage problem. Most utilities will fix the problem if you complain both vocally and more importantly, in writing. You apparently are at the end of the line or transformer drop for your neighborhood and have a voltage support problem. They need to either add another line transformer for you or add capacitors to boost the voltage support. But, if you don't complain in writing, nothing will happen. Second, PS audio makes power conditioners/generators where you can actually increase the output voltage to your system. Look on PS Audio's web site. But answer the first questions first. does your voltage fluctuate? if so, you must have the local utility fix the problem. You need voltage support for your area. They will fix this.

208V doesn't seem to be an issue.

If the Hong Kong electrical system standard is anything like that of the UK, with a lower limit of -6%, then 208V is within normal voltage tolerance range.

Are you sure what you are describing is due to low voltage?

I don't know, the OP did state that the voltage standard is 220VAC. This to me means that if your equipment was designed to operate at 220VAC, the 208VAC may trigger problems. I know that for my Audio Research REF 3, if the voltage dropped by the same percentage here, it would go into low voltage shut down. Turn Table motors won't run correctly at such a low voltage. It sounds like a pretty large issue to me.

enjoy

If low voltage is indeed the problem, a voltage regulator like those from Furman should solve that issue. Here's a link to the Furman distributor in Hong Kong, Sanecore Audio:

http://www.sanecore.com/

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Thanks for everyone advice.

Hi, Minorl, it's not only low voltage problem happens in my house, but also the voltage will fluctuate very much sometime. Last night (~10pm), I measure the voltage and it keeps swing among 208V-212V-218V-206V-212V..... it rises and drops, and then rises and drops..... it is really unstable.

I already write to the local utility abt this unstable and low voltage problem, and they are carrying out on-site inspection. They also apply a "voltage recorder" device to my house to record the voltage data for a week, but they haven't given me any result found. So, I think they are still in investigations. After 1 or 2 more weeks later, if I still get any reply, I will write to them again.

In the meantime, I try Stavol transformer (made in Japan), which is also a stablizer and able to keep 220V output. I measure the output from Stavol and it's 222V-223V. The soundstage focus improves and the sound is more lively, like a person in good spirit!! I also try Equi=tech Q1 (not sure the model name but the smallest model in the toppest grade) before, and I got the same result. However, I find that the sound, is somewhat "artificial" (not natural enough). I don't know how to describe it. Compared with plugging directly to powerbar or wall sockets, the "step-up" transformer will make the sound not natural enough. Plugging into powerbar or wall socket gives me a kind of "relax" feeling.

Cykeric; It sounds to me as if the local utility has jumped on the problem, is investigating it and will fix it with the solutions I mentioned earlier or something else. they know that low voltage can cause all sorts of damage to very expensive equipment and typically, when people complain in writing, they investigate and fix the problem. I'm sure they will fix it and I hope things work out for you.

enjoy

Thanks Minorl. I am not sure if they are still investigating or not. People usually tends to be lazy, and need someone to push or pressure to get the good job done.

The very worst outcome may be, they just say the voltage swing & low is due to highly use of home appliances (eg. air cond in summer), and it's unavoidable, because it's still in +-10V range. Anyway, I will check up with them abt the current status.