Mains down to 161V

[JoeyDaRench]

I've noticed at night mostly that the lights dim and the fans slow down. My AVR that I use for my computer devices will be clicking away. I knew all this was due to voltage fluctuations but I really didn't give it much thought.

Tonight, our main house pressure pump stopped working. It was extremely hot. This had happened once before and I cooled it off with a fan which allowed it to reset. Again, I didn't give it much thought. Tonight when it happened again,

I just figured it was a faulty pump. But, I also have an irrigation pump that is the exact same brand/model and I plumbed the system to easily switch between the pumps. When I re-routed the water and turned on the second pump, I noticed the

distinct sound of a VERY laboring pump. The light bulb in my brain lit up. I got the meter out and the mains voltage coming in was at 161 volts.

This clearly has been happening for quite some time (dimming lights, slow fans, etc) but I just didn't put 2 and 2 together. Now I know. Shortly later, the lights got brighter and the fan faster. I checked the voltage. 185 volts now. Still not right, but better.

The pump sounded better, but certainly not right.

Our house is at the end of the main line. We're about 550 meters from the transformer that feeds our village...I would guess maybe 50 or so houses. The line on the poles from the transformer to me is 35mm2. There are a few places (powered by the same transformer) that may use a heavy load such as a couple of auto body shops, but they really don't look all the high end. Maybe a compressor or two.

I will go to the PEA tomorrow, but I'd sure like any suggestions on how to best speak with them in a way that will get them to help me. I've checked the voltage during the day and it's around the 220 mark. I'm guessing that when/if they come over, that's where it will be.

Hard to show the problem when it's intermittent.

One last thing, I've noticed lately at around mid morning my AVR starts going nuts-clicking away. Again, I haven't looked at the incoming voltage as I really didn't notice any other trouble and the AVR was doing it's job.

Any help would be great.

Thanks.

[stoneyboy]

If it's any consolation we had a complete power cut for 3 hours the other night.

I was sweating like a Paedophile in a playground.

[RichCor]

Are you on a Single or 3-Phase service?

If Single-Phase you may want to investigate the voltage level available on the remaining two phases, and if they are stable when yours drops down, then have PEA switch you to a different phase.

What time frames do you notice the power drops occurring? Evenings would indicate residential use by Air Conditioners, Water Pumps, TVs and Fans as people come home up to the time they get ready for bed. If you could isolate a neighborhood culprit then PEA may have a better idea of mitigating the problem.

If PEA can't or won't provide you with a more stable mains feed then your other alternative is to get a whole-house AVR (hopefully one that can work with the variation occurring on your mains line (160VAC ~ 240) on 3-Phase or the best of the Single-Phase feeds.

[Crossy]

Indeed ^^^. Your first stop should be PEA, if possible keep a log of the supply voltage so you can show them the fluctuations.

If PEA fail to come up with the goods it's time to get an AVR, there are a couple of threads about these, where to get them and how much to expect to pay.

[JoeyDaRench]

Thanks all for the information. We are on single phase.

I will be talking with the PEA this morning, but I do suspect they will blow me off.

[JoeyDaRench]

Spoke with PEA this morning. I was VERY WRONG. They were tremendously helpful. Actually sent someone right over. During our meeting at their office, they were clearly trying to say that we just have too high of a load. Once I explained the load at the time was less than 10 amps, and they figured they couldn't BS me (although all the talking was through my wife), they agreed to come by. Luckily, at the time they got here at 9:30am, the voltage as at 192 and we only had a 4 amp draw. They said they were going to raise the line voltage by adjusting the transformer. I didn't know they could do that. But, this afternoon, they were out again, the power went out for a half an hour and they came back saying they charged our transformer to a different phase to hopefully help. We are single phase (2 wires) coming down the 550 meters to our house so they did what they did at the transformer. Right now we're at 225 volts and things seem fine. I'll be watching carefully tonight.

[Crossy]

Great.

Continue to keep an eye on it, do watch the maximum voltage too, if it goes over 240V it's worth going back to PEA.

[JoeyDaRench]

So now I'm beginning to wonder. I'm sure it's that I don't know what I'm looking at but.....

I just went out and looked at the transformer. On the poles coming into our village, at the very, very top center (actually extended up about a meter) there is one wire going to all poles. I believe this to be a grounding or common wire. Below that are 2 wires-I believe these to be the high voltage wires. From those, the transformer is connected and off the transformer, there are 2 wires running up and down the village and to our house. One would be hot, the other neutral. Now here's the question. I figure that the high voltage wires are similar in that one is hot and the other neutral. If that is the case, how did they "connect the transformer to another phase"? Maybe they did it at the main road where the high voltage wires are connected, but I really don't know.

But, it's now 7:00 pm and the voltage is at 199. One of my fluorescent bulbs won't lite. All else seems okay but I'm sure it's not good for our pumps. Last night, the trouble was at around 8:00. I'll keep watching it.

Any ideas on how they did their "phase change"?

Thanks again.

[Gonsalviz]

So now I'm beginning to wonder. I'm sure it's that I don't know what I'm looking at but.....

I just went out and looked at the transformer. On the poles coming into our village, at the very, very top center (actually extended up about a meter) there is one wire going to all poles. I believe this to be a grounding or common wire. Below that are 2 wires-I believe these to be the high voltage wires. From those, the transformer is connected and off the transformer, there are 2 wires running up and down the village and to our house. One would be hot, the other neutral. Now here's the question. I figure that the high voltage wires are similar in that one is hot and the other neutral. If that is the case, how did they "connect the transformer to another phase"? Maybe they did it at the main road where the high voltage wires are connected, but I really don't know.

But, it's now 7:00 pm and the voltage is at 199. One of my fluorescent bulbs won't lite. All else seems okay but I'm sure it's not good for our pumps. Last night, the trouble was at around 8:00. I'll keep watching it.

Any ideas on how they did their "phase change"?

Thanks again.

The fluorescent lamps that look like they are all made together will light with low voltage.

[JoeyDaRench]

Well, it's 8:05pm and we at 180V. The PEA (who said to call and they'd come out) says "well there's really nothing we can do tonight". They say they know there is a problem, just not what is causing it.

Here we go. Round and round.

[RichCor]

In our area the Neutral wire is BARE, and the 3 individual Phase lines run just below it.

Each house meter taps the Neutral and one of the three Phase lines (in an attempt to keep the 3 phase line usage balanced).

I'm guessing that two of the Phase lines run through your village, and the other Phase line runs off in another direction?

Unless you have someone inside your village pulling major amperage at night I would say that the main High Voltage transformer is just too small to service all the users.

Such things happen when a little village goes from being agrarian farmers in need of nothing to TV-watching consumers of all things electrical.

Your village needs a larger High Voltage transformer.

[IMHO]

Your village needs a larger High Voltage transformer.

... But it's highly likely your PEA doesn't have any budget to buy one, so you will be offered to pay for it

[Crossy]

Give PEA a little longer to sort the issue, but start looking into whole-house AVRs, these will be a lot cheaper than funding PEAs new transformer.

200V (-9%) shouldn't be an issue but much lower will start causing motors to overheat etc.

EDIT one of several AVR threads here http://www.thaivisa.com/forum/topic/671566-voltage-drop-solved/