Is Electric Voltage Fluctuation Same All Over Samui?

[animatic]

As I stopped understanding Physics when it came to electricity most of the above is like Chinese to me...

But one thing I know: since 2001 we did not loose any electronic appliance in Lamai - even without UPS's due to voltage fluctuations. Before in New Delhi the fluctuations killed almost all of them - even with UPS. We did one thing in Lamai as we had 3 phases but only one was used - we put AC's, computers, washing machine, dryer etc. on all of the three phases and it's working.

Might be not the most helpful reply - but I do not have a reason for a "phobia".

Lamai has stable power. It is close to Raja Ferry where the transmission station is.

It also has a higher power regulating units / per users ratio.

Banrak is dead opposite Raja and has Chaweng eating up potential in a bit way before

it gets to it. And Maenam to a lesser extent. Mostly it's not enough transformers

for the new houses installed. And no one has thought of a way to group finance

or at least co-op finance enough current/voltage/amperage regulators to do the job.

They expect EACH uncomprehending landord with complaining tennants

to finance a transformer alone. Ridiculous..

[mattias33]

What a load of crap. Not even worth a comment. So............ will i.................No.

Read it and believe or read it and .

To each their own as we say on this forum.

[PoorSucker]

It blew up my Mac, and won't work at ALL for a job in Fishermans Village.

Well... it was a Mac.

[animatic]

It blew up my Mac, and won't work at ALL for a job in Fishermans Village.

Well... it was a Mac.

yeah yeah yeah.

Well it's a Mac with twin processors, 1 gig of ram , and a 1.2 terrabyte of disc space...

Not exactly a light weight iMac for net trolling..

It was a power supply burn and was fixed in BKK for 1,200b

that I wished I hadn't had to pay.

The amp is twin 90w Peavey with 8 effects built in... won't run, no power.

Was just down at the electric company today.

They have from 70-100 cap/trans banks sitting in the yard,

waiting for someone to pay the electric company into installing.

At fluctuating rates depending on WHO needs it installed.

No matter that the whole islands electrical system is out of balance,

the customers must pay huge amounts.

Not the electric company

spreading the pain over many customers

and making the system better for all customers.

Il Logic from an alternate universe...!

Edited October 15, 2007 by animatic

[elkangorito]

My comments in red.

Hi,

I live in Bang Rak, and have a constant problem with electricity. I have a digital multi-meter, and monitor the voltage fluctuations quite a bit. When it becomes most serious is during the frequent blackouts, however, every day seems to hold problems with power fluctuations, and the nature of these has changed in the 5 months since I moved here from Chonburi.

This is serious enough for me to want to do something about it, including moving to another part of the island. Is it the same everywhere? A friend said it was noticeably worse in my particular area - across from Ting Tong Bar on the Ghost Road.

My lights dim, fans and A/C slow, and my computer's UPS starts beeping. A month ago, this only occurred during the evenings, but now it starts around 8 AM. Up until last month I would see a maximum of 210v and a minimum - very low - 139v. When the power dropped below 175v it would start beeping.

These "voltage drop" problems are directly transformer related.

Now I see high numbers - up to 305v, but usually around 255v. Presently when the # drops to around 235v and less, the beeping starts. I can't figure out why the readings on my multi-meter would change. I also think I need a larger UPS, or line conditioner, to deal with some other electronic components I want to hook up. To summarize.

What you describe possibly relate to "harmonics". More at the end of this post.

Is the problem island-wide?

Are there any areas outside mine that are better?

Is there a way I can fix the problem?

Are line conditioners available in Samui?

Thanks,

Buzzer

I use to live across chaweng lake in a worn bungalow-village. There we had tre powerbreaks/week and often problems like you describe, but one look at the electric wires in the neighbourhood and one could easily understand why. Completely overgrown with tree and buches in beetween the wires.

With reference to the bolded words, this could definitely contribute to the problems on Samui.

To many houses / businesses on one transformer. Bigger problem usually with private landlords adding more bungalows but not beefing up the power supply. Next door puts the kettle on and your lights dim.

Overloaded transformers will cause a voltage drop.

This is only one brand of automatic voltage regulator, others are available, usually cheaper in Surat.

http://www.siliconthai.com/

Very important to get the bigger ones fitted by a qualified electrician.

Pay the extra and get an Automatic machine. ( it adjusts its output as the incoming voltage goes up and down )

If you choose the cheaper manual version when the power comes back to normal your transformer will give much to high a voltage and blow up your TV ect...

Very true.

Hope this helps

They put in a big new transformer in our neighborhood last year or so. But it has more than just our little offshoot line on it.

Also, we didn't start having problems like this until our neighbor put in all the aircon rooms.

**edit*** to be fair, we've always had problems but they seem to get worse during the high season esp when our neighbor has all his aircon rooms full.

If your neighbor doesn't have any problems, you should check and make sure your power consumption is under the rating of the cables to the house! If you are overloading the cables, this is a big fire hazard.

A good point but most Thai "consumer mains", aluminium or copper, are a minimum of 35 mm squared & in many cases, 50 mm squared, which can handle a 80/100 Amp supply.

Do you have a clamp-on meter amp meter that can go around one of the conductors of your incoming supply? If not, check your voltage in two different places, at the meter, and at an outlet as far away from the meter as possible.

Automatic Voltage Regulators are great at protecting yourself against PEA problems, but if the problems are internal, they do pose a higher risk to yourself. They will continue to draw equal power, no matter what the voltage is. This leads to higher current consumption at low voltages.

Very true...listen to this advice.

175-305V is not a normal range for the utility. 200-240V is beyond western specifications, but not too unreasonable for Thailand. The excessive voltage variations you see, especially at the high end, suggest a real problem. Be careful.

In actual fact, this is not quite true. For example, Australia, which has a very stable electrical supply, has an allowable tolerance of +10%/-6% of the supply voltage. In this case (Thailand), no lower than 207v & no higher than 242v, which is quite acceptable for most types of equipment. Australia uses a similar system to that of Thailand.

We have our own meter (I am guessing this is what you mean by transformer?) but are on a small line branching off from the main one. Neighbor (before us on the line) has put in large a/c house and several ac/ bungalows. Could he be drawing the power away from ours even though we do have a good size meter--we paid extra to get a meter that draws more power.

Your extra payment did allow for an increase in Maximum Demand. More at the end of this post.

Your problem is unlikely to have anything to do with the transformer and certainly nothing to

do with the meter. All a meter does is measure.

Nothing to do with the transformer? Please clarify your statement.

Most likely it is because the overhead line running to your house is too small.

Unlike in the west where copper is used for medium voltage lines, aluminium is used in Thailand

due to it's lower cost, and long runs can result in voltage reductions if the conductor size is inadequate.

Naka.

See above for standard minimum aluminium consumer cable sizes in Thailand.

So you don't think the automatic voltage regulator would do us any good then? Our neighbor is closer to the transformer than we are but I really don't see him doing anything about this since it doesn't affect him.

Could be a "Thai classic" case of incorrectly connected cables. More about this at the and of this post.

I tried a digital voltage regulator,

When power dipped below 150v it shut down.

I went away for one night it fried my Mac,

which was turned off....

Some things just WON'T run with those units.

I have a special guitar amp, NEVER works in Fishermans Village.. NEVER.

A good APC ups is the trick for computers etc.

The funky voltage usually doesn't seem to effect DVD and CD players,

though power amps can get quieter.

Closeness isn't the issue, but total load on the line

after the regulating transformer/capacitor bank. Where are these "capacitor banks"?

There just ain't enough juice and wht there is isn't often enough regulated,

to moderate the global load on the far side of the island.

This, in an other country, would be the electric companies responsability.

Making sure enough transformers for the load are out on the lines.

Not trying to palm off the cost piecemeal on clueless landlords.

I blame Surrat Thani's provincial office milking the Samui

golden Tax Goat as long as possible, before their lose it to grow,

and keeping all the cash at home,

and not helping repair the over taxed infrastructure here.

You want better roads and electric power?

Start registering out of district Thai's as Samui residents.

We get another few hundred, Samui becomes a district itself,

and MUCH more tax money stays on island.

Here are the "real" potential problems on Samui;

1] Many transformers are overloaded, which will cause a voltage drop.

2] Many farang residences use lots of power, which, if the Thai electricians have done their "typical wire twisting" (no proper mechanical connectors), will also cause a voltage drop under high load (high current). This situation can also cause fires. The "Thai" cable connections are generally cables that are twisted together & then bound by electrical tape. These types of connections are dangerous & illegal.

3] The high voltage experienced by some could quite possibly be attributed to "voltage harmonics". That is, the load is predominantly computers, compact fluorescents, electronics, "inverter" air conditioning etc. This is only severe if the supply size is similar to that of the demand. Ie the load is almost equivalent to the transformer capacity. This is NOT a consumer problem. This problem must be rectified by the energy authority.

4] Supply lines that are interferred with by trees etc can be the cause of a voltage drop problem.

5] Thai energy authorities do not seem to do "area" maximum demand calculations. Therefore, if you decide to build a house or buy a place & "add on", no thought is given to the amount of power you can use. Again, this is the problem of the energy authority...not your problem. They must be able to supply you, as the paying consumer, with reliable electricity.

6] Capacitors are not used in the supply of electricity to any premises.

7] For those who don't wish to wait for the Thai authorities to solve the electrical problems, a possible solution is to employ an inverter/battery arrangement...expensive but reliable. UPS's are only required to protect computer data & are not recommended for any other purpose. If an inverter/battery arrangement is used, a UPS is redundant.

8] Automatic Voltage Stabilisers can be used but not in this situation, for reasons previously stated.

9] Generators can also be used & would be an excellent solution to the given situation. They provide a good sine wave output providing that a reputed unit is used. UPS units & inverters may NOT provide a "true" sine wave output (many of these things provide a PWM output - Pulse Width Modulated), which can affect sensitive electronic equipment.

10] Sizing inverters, UPS units & generators cannot be guessed. If help is required, ask me. I can do this.

If you are an "established" electricity consumer, do not pay for any transformer upgrade. This is the responsibility of the energy authority.

[PoorSucker]

X-good reply elkangorito

This q has come many times, maybe get pinned, (SBK?)

[elkangorito]

Thanx Poorsucker (what a handle...lol).

Believe it or not, if this sort of topic was posted in the "Real Estate etc" section, answers to these problems may have been quicker in forthcoming.

My pet peeve is when people start giving electrical "advice", which is inaccurate & can kill. Unfortunately, there is no room for error when it comes to electricity.

[PoorSucker]

I have been working with computers in all my life, and half year with car electronic.

Every time i touch a workstation here a get a chock.

Can't they do any ground here?

Now when a touch a computer case here, I try to where gloves.

Big recommend to everybody that don't have laptop..... Buy UPS.

If have seen so many going to the shop after lightning.

[ClaudeFeller]

To explain a little bit what "elkangorito" (very good post!!) means with an inverter-battery arrangement:

You need deep cycle batteries (DC voltage) and an inverter to transofrm this DC to your AC demand. A good inverter will produce a pure sinus wave output suitable for your devices. More than that you need a charge controller to recharge your batteries when grid power is reliable again. The inverter/charge controller is one unit, output between 2 kW and 8 kW as far as I know. Here an example of an installation, not on diesel generator addicted Koh Samui / Phangan / Tao but in Laos...

Edited October 15, 2007 by ClaudeFeller

[ParadiseLost]

I live on KP and my UPS (Five-Star brand?) got fried and my PC power supply was damaged by a bad brown-out last week. In fact my fridge light stopped working too!

Mention was made of protecting TV equipment - would it be okay to hook these and PCs to the same UPS; or is it advisable to protect them separately?

Can anyone please give details such as pricing and name of shop to buy a reputable UPS (APC was already recommended) on KP or KS? Perhaps Surat Thani is the best.

[elkangorito]

I have been working with computers in all my life, and half year with car electronic.

Every time i touch a workstation here a get a chock.

Can't they do any ground here?

Now when a touch a computer case here, I try to where gloves.

Big recommend to everybody that don't have laptop..... Buy UPS.

If have seen so many going to the shop after lightning.

In Thailand, the "earthing" (grounding) of the necessary electrical equipment is supposed to be done. This equipment predominantly has metal chassis'.

I live on KP and my UPS (Five-Star brand?) got fried and my PC power supply was damaged by a bad brown-out last week. In fact my fridge light stopped working too!

Mention was made of protecting TV equipment - would it be okay to hook these and PCs to the same UPS; or is it advisable to protect them separately?

Can anyone please give details such as pricing and name of shop to buy a reputable UPS (APC was already recommended) on KP or KS? Perhaps Surat Thani is the best.

I would not connect a TV to a UPS that was already supplying a computer. The reason for this is that the UPS may not be able to perform under the additional load. If you calculated the load used by the TV & computer, you would be able to purchase the correct sized UPS to do this job.

If anybody needs some electrical help/clarification, try this website;

http://www.crossy.co.uk/wiring

[Pilchard]

To explain a little bit what "elkangorito" (very good post!!) means with an inverter-battery arrangement:

You need deep cycle batteries (DC voltage) and an inverter to transofrm this DC to your AC demand. A good inverter will produce a pure sinus wave output suitable for your devices. More than that you need a charge controller to recharge your batteries when grid power is reliable again. The inverter/charge controller is one unit, output between 2 kW and 8 kW as far as I know. Here an example of an installation, not on diesel generator addicted Koh Samui / Phangan / Tao but in Laos...

Very nice set up.

Is this not just a giant UPS system ?

[ClaudeFeller]

To explain a little bit what "elkangorito" (very good post!!) means with an inverter-battery arrangement:

You need deep cycle batteries (DC voltage) and an inverter to transform this DC to your AC demand. A good inverter will produce a pure sinus wave output suitable for your devices. More than that you need a charge controller to recharge your batteries when grid power is reliable again. The inverter/charge controller is one unit, output between 2 kW and 8 kW as far as I know. Here an example of an installation, not on diesel generator addicted Koh Samui / Phangan / Tao but in Laos...

Very nice set up.

Is this not just a giant UPS system ?

Yes!

As far as I know an UPS provides 200 Wh, while the set up above provides about 20 kWh.

No!

As far as I know an UPS doesn't have a wide overload capacity while the overload capacity of the set up above will allow to start the engines of air cons, refrigerators and conventional lighting, where the start up power is about triple the average load. Furthermore, the in-built multifunctional contact enables you, for example, to start a diesel generator to recharge batteries or to cut the power for less priority loads when the battery is lower than a given threshold.

[elkangorito]

As far as I know an UPS provides 200 Wh, while the set up above provides about 20 kWh.

No!

As far as I know an UPS doesn't have a wide overload capacity while the overload capacity of the set up above will allow to start the engines of air cons, refrigerators and conventional lighting, where the start up power is about triple the average load. Furthermore, the in-built multifunctional contact enables you, for example, to start a diesel generator to recharge batteries or to cut the power for less priority loads when the battery is lower than a given threshold.

You're almost on "the mark" Claude . Sorry but this will not be a short post.

UPS's come in a large range of sizes from a couple of hundred VA to many hundreds of kVA.

The purpose of a UPS is to provide "uninterrupted" power & therefore has the ability to switch from "normal" supply to "backup" supply in about 5 milliseconds (or less), which is achieved by using IGBT's (solid state devices). There are generally 3 types of UPS's, the "online" or "dual conversion" being the best. The "online" type provides a true sine wave output for sensitive equipment as well as filtering the incoming "normal" supply. Since a UPS is connected to the "normal" supply, it is prone to the effects of lightning & other transients, which can cause the UPS to fail. UPS's can be sized to accommodate the inrush currents (starting current surges) of motors etc although running a fridge with a UPS is unnecessary & overkill. Essentially, UPS's are designed to support "critical" & sensitive equipment that must not have any interruption to power supply (eg computer data centres). The "backup time" is limited to how many batteries can be linked to the UPS (battery charger capacity). UPS's can be online for as long as the batteries can last (not desirable).

An inverter has a somewhat different purpose.

Unlike the UPS, it is not in any way, connected to the "normal" supply & therefore will not provide uninterrupted power. An inverter can be activated automatically or manually & in any case, can take up to 1 minute to supply alternate power in the event of a "normal" supply failure. This is achieved by using "transfer switches". A transfer switch MUST be used as it is dangerous (& illegal) to allow the inverter supply to connect with the "normal" house supply. This switching arrangement can only be performed correctly by a licensed electrician or preferably, an engineer.

Like UPS's, inverters use a battery backup in order to supply the installation with power. Also like UPS's, there are different types of inverters, the most common being Pulse Width Modulated (PWM or psuedo/quasi sine wave). The PWM type does not provide a true sine wave output & therefore can damage some sensitive equipment like electronic fax machines, scanners, photographic equipment etc. If sensitive equipment is to be supplied with inverter power, use a "true sine wave" inverter...more expensive but much better.

The type of batteries used with inverters can vary but if backup power is required for long periods of time, "deep cycle" batteries are recommended.

What's the difference between a deep cycle battery & an ordinary battery?

Deep cycle batteries can purportedly tolerate a deeper discharge without a reduced loss of life, compared to ordinary batteries. Having said this, there is a thing called Depth Of Discharge (DOD), which affects 98% of all battery types. As a general rule, by NOT discharging batteries by more than 50% of there total charge, the life of a battery can be more than doubled. Of course, this means doubling the size of your battery bank. Deep cycle batteries are expensive...treat them nicely & they will serve you long & well.

The charging of a battery is very important.

Fast or overcharging can quickly reduce the life & the output of a battery. For this reason, most good quality inverters incorporate a "constant current" battery charger & the inverter will also have a "battery bank equalisation" function. For this reason, it is not recommended charging deep cycle inverter batteries with a standard "portable" generator.

A word on "portable" generators versus "standby" generators.

By & large, "portable" generators are "brushless" & do not produce a good quality sine wave. The only exception to this would be the "brushless" portable generators that use output inverter technology, which do produce a clean sine wave. "Portable" generators are usually low power (under about 7.5kVA) & are designed to supply things like power tools, nonelectronic fridges, small motors & most TV's. Also, they generally can only be operated for a limited period of time (eg 4 hours) at full load. For this reason & if a "portable" generator is used as a backup supply, it is strongly recommended that the generator load does not exceed 80% of its maximum rated load, in which case it may be run for longer periods without affecting its life expectancy. Portable generators usually have a poor voltage regulating ability (>5%).

A "standby" generator is usually not "brushless", does not use electronics to produce a clean sine wave (it produces the waveform mechanically), has a good voltage regulating capability (<4%), can be run continuously at its rated load & can safely supply sensitive electronic equipment with power.

Inverter size calculation.

The first thing you need to do is determine the total load that the inverter will need to supply. The inverter must be sized to accommodate the starting current for each of fridge/freezer, plus the extra load of the lights, T.V. & phone/fax etc. You may need to look on the compressor of both the fridge & freezer to get the info you need. If possible, try to find the L.R.A. (locked rotor current) of each compressor. This info may be in any operation manuals (if you still have them). If the L.R.A. is not indicated, use the F.L.A. (full load current) & multiply it by 4.

Inverters typically have 2 ratings (like a generator)...a "continuous" rating & a "surge" rating. You may also notice that generators & inverters are sized in VA (Volt Amps) & usually not kilowatts...there is a good reason for this. Let's do a sample calculation;

Formulas - W (power) = E (volts) x I (current) x P.F. (Power Factor). We need to find the current (I) so;

I = W divided by (E x P.F.)

Power Factor is used if you can't find the FLA or LRA of the fridge/freezer & only the wattage is known. Note - I have assumed that the fridge & the freezer have a P.F. of 0.8.

Continuous Load calculation.

4 x 60 Watt incandescent lights - - - - - - - - - - 240 divided by 240 = 1 Amp.

1 x 300 Watt fridge - - - - - - - - - - - - - - - - - 300 divided by (240 x 0.8) = 1.5 Amps.

1 x 300 Watt freezer - - - - - - - - - - - - - - - - 300 divided by (240 x 0.8) = 1.5 Amps.

1 x 300 Watt TV - - - - - - - - - - - - - - - - - - -300 divided by 240 = 1.25 Amps.

1 x 100W "printer" fax/phone - - - - - - - - - - - - 100 divided by 240 = 0.4 Amps.

Total continuous Watts as listed - 1240 Watts.

Total continuous current as calculated - approx 6 Amps.

Surge Load calculation.

The only items that will have a surge current are the fridge, freezer & TV.

1 x 300 Watt fridge - - - - - - - - - 1.5 Amps x 4 = 6 Amps.

Fridge surge - - - - - - - - - - - - - - 6 Amps - 1.5 Amps = 4.5 Amps.

1 x 300 Watt freezer - - - - - - - - 1.5 Amps x 4 = 6 Amps.

Freezer surge - - - - - - - - - - - - - 6 Amps - 1.5 Amps = 4.5 Amps.

1 x 300 Watt TV - - - - - - - - - - - TV surge is approx 0.5 Amps.

Total surge current - 9.5 Amps.

Your inverter will need to supply a continuous current of 6 Amps.

Your inverter will need to supply a total surge current of 6 Amps + 9.5 Amps = 16 Amps.

Converting these figures to "Power" (VA);

16 Amps x 240v = 3 840 VA (Watts) surge.

6 Amps x 240v = 1 440 VA (Watts) continuous.

Since you will not find an inverter with these exact "continuous" & "surge" ratings, you must buy an inverter that can accommodate the surge rating. ie you will need an inverter with a surge rating of no less than

3 840 VA for the above situation.

PHEW!!

[elkangorito]

Oops!!! Sorry, I forgot that I'm in Thailand & that 220 volts is used...NOT 240 volts. Not to worry, just insert 220 instead of 240 in my calcs.

[ClaudeFeller]

Elkangorito,

Good post, your calculation is understandable.

Your "continuous load" numbers are very high, 300 W for fridge / freezer is a very large device (US standard?) and 300 W for TV is a 42'' plasma-TV. Normal devices are about 100 - 150 W. And who still has 60 W bulbs, can buy 11 W energy saving bulbs..

Assuming this you need 800 VA continuous load maybe 2000 VA for surge load - IF those devices start up at the same moment!

My set up can be overloaded by factor 2.2, so it would be good enough to have a inverter with 1000 VA continuous load, surge load of 2200 VA can be managed.