1) Electrical Power Lines 2) Oscillating Power

[gdhm]

1) May I ask if electricity runs evenly along powerlines?

When power leaves the stepdown PEA transformer at 220V, is it evenly spread all along the 220V power lines it serves of does it serve those nearer to the transformer much better and those near the end of the line.

I ask because it has been confirmed we are at the end of out line (all but 4 houses) shortly 5 as a new large house has been added.

2) When we first moved into out troublesome low Voltage soi we only experienced problems with low power especially at night and in hot weather. In the first 2-3 months we occasionally experienced oscillating volts (every second or so for anything from 1 min to 20 mins).

Oscillating is between 0 to 15 Volts but is not consistent in time or change (examples it can read like 204V, 199V, 200V, 185V, 190V, 189V etc.)

or 214V, 212V 204V, 206V, 204V, 214V, 210V

However during the last 2 months it has got much worse many times a day or night and for longer periods. The only thing that has changed is that the voltage is lower than at first. but it happens when the voltage is not too bas in the mormings at arounf 212V plus or when it is as low as 178V at times in the evening.

I am hoping someone (maybe Crossy who has kindly furnished me and others with so much insight into understanding electricty and problem solving) can suggest possible causes and why a situation can worsen.

I as a layman wondered whether this sort of thing can happen if power demand is too stretched but then it happnes when volts ar enot too bas (212V) or can it be we are affected as we are near the end of the line.

3) May I ask about effect of items on voltage.

Firstly, am I correct in assuming that a strong power supply at 220V will not usually go down in volts when a few demanding items come on line (or only for a spilt second)

In our case: At night when I switch on a 18,000 btu aircon and its cooling kicks in the volts drop 4 or 5 Volts. A shower heater will knock that down another 3 V. Two aircons drop voltage by about 9 Volts This is significant when the Volts are 196V and then drop with 2 aricons to around 187V

Is this likely to be reflected in our whole Soi's (and others along the same powerlines) experience or would it be likely only our house is badly affected. We have a single meter 30 AMP with TWO power lines leading to 2 separate Mains Fuse boxes.

I suppose what I am seeking to understand: Are our voltage drops worse (when we switch on our aircons etc.)

due to our own house demands than other in the soi whose demands may be less, due to how it connected to OUR house from the meter or are ALL's volts along the line adversely affected equally.

Our PEA has told us if we pay 100,000 Baht we can have problem solved immediately otherwise we are but one of many for their inadequate budget. TYPICAL!!!. Do not have that sort of money and anyway they will opnly add more to the lien as hosues are built and then we may be back to square one in a few years.

PEA official asked us why we connected to a poor supply. OK I admit we never guessed it was bad as where we lived two sois away is perfect (different set of lines I suppose).

Tempted to respond why have the PEA just connected another new house being built at the VERY END of our Sois already inadequate supply.

The house is big and when on line will push the whole soi and others with the same supply line to critical low voltage levels (already: lowest seen 168V) Normal for hot nights 178V -185V is very common).

I need this knowledge so I am not palmed off by the PEA by false logic offered (already many different excuses) and me not understanding enough to recognize this.

Thanks Dave

[Crossy]

Quick and dirty answer, proper one later when I get more time

The power leaves the transformer probably at about 230V. If no current is being drawn (no load) you'll see that 230v at the far end

Unfortunately as you start to draw current the resistance of the wires drops some of the voltage (Ohms Law) and you see less and less at the far end. If the load changes, the voltage lost changes and hence your supply goes up and down with load (as you've noticed with the aircon and water heater). This drop will get worse the further you are from the transformer, those right next to it may not notice any drop at all.

You are near the end of a long feed and it sounds like both the feed and the transformer driving it are near their limit Adding more load (new houses) can only make things worse.

The only real solution is for PEA to upgrade the supply with a new transformer and associated wiring. The 100,000 Baht solution will get you your own transformer and high voltage feed to it. Problem solved until PEA decide that it's really their transformer and start attaching new homes to it

[katabeachbum]

We did get a new transformator, and where promised we would decide how many could connect. 3 years ago

Now PEA is connecting more and more without us accepting, and voltage is shit again.

Votlage below 200 can seriusly harme/damage your equipment.

[longball53098]

I have seen some areas or sois where the PEA adds a transformer to step down just one leg of the 3 phase and provides this phase down a soi with just a few homes. They may run the other legs to others sois.This may be the situation on you're soi. Now in you're case the feed to these 4 or 5 houses has an issue like Crossy is saying due to the length of the cable and the load from the homes on that soi. When the PEA did the original load plan for that soi maybe 10 or 20 years ago it was adequate but now with power hungry homes it cannot meet the demand. If you're soi is supplied with just a single phase of 230 volts it really needs the 3 phase to be supplied so the homes can be balanced out on the different phases.

I have a friend that just completed a house build near me and that is exactly his situation. At least 10 houses are being supplied from a single phase off a transformer somewhere about 200 or 300 meters from his house. The plan to add 3 phase down his soi is still years away.

[tjo o tjim]

I'll offer a "green" solution to your problems:

-Switch to a solar hot water heater.

-Install insulation.

-Pre-cool the house by dropping the temperature an hour or two before the voltage usually sags. Increase the temperature when you hit the sags.

-Turn off lights that don't need to be on. Consider using smaller, low-wattage lamps rather than a single large light in the room.

-Make sure your appliances are as energy efficient as possible.

Try to convince your neighbors to do the same.

Eventually, you will need a new transformer. If you have 15% voltage drop, it is expensive to run, prone to fail, and will damage any motors and some electronics. It is also a fire risk. Getting it done and done right is another matter altogether. If you can push that eventuality back a year or two until growth stabilizes in your area, you are more likely to get a better long-term solution at a lower cost.

(Crossy-- Is PV viable yet in LOS? I know duties killed the economics before, but haven't checked in years.)

[skipvice]

Try to convince your neighbors to do the same. I don't think so, all my neighbors are Thai.

[gdhm]

Try to convince your neighbors to do the same. I don't think so, all my neighbors are Thai.

Same here and most are poor.

The Solar idea for hot water is good BUT we only use our showers a few minutes at a time 4 times a day and kitchen water heater when washing up. Their drain although significant in Voltage drop is only minutes at a time and infrequent.

Dave

[silentnine]

voltage in my house just outside pattaya is terrible.

i've put up with it for a year . having brown outs as i switch on more aircons . or having to switch off the aircon to use the microwave !

so today i went out and bought a couple of fancy ups unti with digital displays showing in and out votage.

the problem is now the voltage keeps dropping below 170v and the ups's don't charge ! lol

so not only can i not cook and shower at the same time.

now i can't run a ups

[gdhm]

voltage in my house just outside pattaya is terrible.

i've put up with it for a year . having brown outs as i switch on more aircons . or having to switch off the aircon to use the microwave !

so today i went out and bought a couple of fancy ups unit with digital displays showing in and out voltage.

the problem is now the voltage keeps dropping below 170v and the ups's don't charge ! lol

so not only can i not cook and shower at the same time.

now i can't run a ups

I have a UPS for my PC but like you the battery cannot cope with constant low voltage drops and cuts out. sometimes I bypass it at night so I can go on working. Problem doing this is that if my PC decided voltage is too low or the supply affects it working properly it invariably just cuts out without warning.

between the devil and the blue sea.

Crossy has advise in a different thread that a solution is an APR, Automatic Power Regulator (no battery incorporated).

I will go this route if the Senior Manager at the PEA is unable to live up to his promises

We finally after 8 months got around the staff blocking contact with this Senior Manager and he was unhappy that had happened AND that we have not been sorted out in 8 months or contact with the PEA.

He has told us to contact him alone via a nominated member of staff (who was in fact the person who "off his own bat" took us to see him as he was unhappy other staff had tried to get us to do "paying extra"options to sort out our low voltage problems which he (AND THE SENIOR MANAGER) said are THEIR PEA's responsibility to sort out free as part of their services and obligations.

The cheapest solution had been to run our own private cable to our house from the nearest satisfactory source (we were told around 10,000 Baht for laying around 200 metres of cable and connecting it)

The Senior Manager said (and I agree with him) this is not a good option and he is against it because:

1) it will cost us

2) others in the road will not be helped so it is a holding solution for one house only.

3) The PEA will get complaints sorting out people one by one "on extra payment options" when it has a duty to deal with all problems.

Maybe we are at last about to have a solution is the near future (not holding my breath completely but the Senior Manager seemed very genuine in his intentions.

Regards, Dave

Edited June 13, 2009 by gdhm

[Crossy]

voltage in my house just outside pattaya is terrible.

i've put up with it for a year . having brown outs as i switch on more aircons . or having to switch off the aircon to use the microwave !

so today i went out and bought a couple of fancy ups unti with digital displays showing in and out votage.

the problem is now the voltage keeps dropping below 170v and the ups's don't charge ! lol

so not only can i not cook and shower at the same time.

now i can't run a ups

Yup, you need an AVR in front of the UPS. Readily available once you know what you're looking for, just make sure it's the right size for your load.

The cheapo Thai UPS I bought a few months back for my TV and AV kit has a built in AVR so that would be the ideal solution if you need a new UPS too.

I'll dig out the spec.

EDIT Here we go, I have a Syndome http://www.syndome.com/innovative_ups.html Sz-801 Pro http://www.syndome.com/brochure/sz-pro-l1_innovative.pdf

Wasn't too expensive IIRC

[katabeachbum]

I just read somewhere government has issued a law about the quality of electricity EPA are allowed to deliver. It was close to Euro spec, IOW we should recieve 220-250 volt at 50Hz. Anyone seen anything about this?

[Crossy]

I just read somewhere government has issued a law about the quality of electricity EPA are allowed to deliver. It was close to Euro spec, IOW we should recieve 220-250 volt at 50Hz. Anyone seen anything about this?

I remember this too from somewhere. Unfortunately neither MEA or PEA have the financial resources to upgrade everybody's supply to meet the spec. Whoever shouts loudest (or pays) gets it done first