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[bronco]

elkangorito, on 2007-03-31 17:28:20, said:

bronco, on 2007-03-31 14:46:17, said:

Does any one realise that a capacitor represents a short circuit to AC?

No it doesn't.

Connect a 16 microfarad cap across a 240v, 50Hz supply;

Xc = 198.9 Ohms

Current in the capacitor = V divided by Xc
= 1.2 Amps.



Power Factor correction.


that's why they are used to couple amplifiers???

As previously mentioned, I would prefer if technical debates were reserved for other existing topics.

that's why they are used to couple amplifiers, that's why when ac is used on a relay that has a capacitor across a set of contacts, you have to cut the capacitor out.
I will agre it's not a short circuit exactly, but in practical situations it must be considered.

[mosquitoman]

Some failings I notice include,

The lack of mechanical connectors, alot of the time wires have been twisted and then taped.

Cable way under size, the use of 1.0mm cable where I would have expected to see 2.5mm cable.

No fuseboard or segmenting of circuits, quite often everything gets lumped onto a single 30amp fuse which then acts as protection for lighting, sockets water heasters etc

Location of sockets and switches in wet areas such as barthrooms and kitchens.

As a previous poster pointed out very little attention to earthing, or earth bonding ie protecting metal items in contact with water.

Use of pooor quality switches, plugs etc

Mish mash of sockets, some that accept round pin, some that accept only square pin etc

MM

[taxexile]

below are some photos of wiring (for lighting and air-con units) installed in the space above the false ceiling of our condo , and under the water outlet of the sink in the kitchen.

this was done by an expensive european run company , we eventually called in a local thai electrician and an air-con company to sort out the mess (wires joined without connectors , and taped with non insulating scotch tape , messy spaghetti wiring , paper and other inflammable stuff littering the space up there , live wires left hanging and untaped etc.etc.

also included is a picture of how a sanitary towel and sellotape may be used to stop a leaking water pipe (for illustrative purposes only)

pm me if you are in hua hin and want to know who not to use.





















the thais sorted it all out after the european company would not pay attention to our complaints , and left it neater and safer.

18 months on , no fires , water leaks , or blown fuses.......... but our fingers are still crossed.

[mosquitoman]

taxexile, on 2007-04-15 09:18:52, said:

this was done by an expensive european run company , we eventually called in a local thai electrician and an air-con company to sort out the mess

My experience too, I have met alot of europeans and antipodeans here who claim to be builders etc, but are complete cowboys.

MM

[taxexile]

there is no shortage of very capable and knowledgable local electricians , the problems arise when they get too much work , and they subcontract or call their cousins away from the hammock to come and help , and the work doesnt get checked or supervised.

[technocracy]

taxexile, on 2007-04-15 03:18:52, said:

water_pi...bandage..jpg

poorly_j...er_pipes.jpg

poor_wir...ng_space.jpg

unsafe_w...trol_box.jpg

hangig_a...throom_2.jpg

fire_risk.jpg

the thais sorted it all out after the european company would not pay attention to our complaints , and left it neater and safer.

18 months on , no fires , water leaks , or blown fuses.......... but our fingers are still crossed.

All I can say is - oh my god! I've just looked through those pictures with my mouth open! To start say what is wrong is pretty much stating the obvious!

I don't know anyway could sleep at night after doing such shoddy work. The 2nd photo with the mass of taped wire right underneath a water waste outlet is just unbelieveable! Did there not even consider the risk of a leak?!? I wouldn't even allow my builders put a water pipe on the wall behind a socket (even though they tried! ).

The company who wired your condo must have shares in 3M!

[taxexile]

yes , it was a bit of a shock when i started to look closely at the work being done , but their attitude when i complained was that it wasnt really their fault because they were very busy and had to sub contract !!

they were silent and red faced when i showed them the sanitary towel though !

[quiksilva]

Just brought a place from Sansiri and moved in over Songkran.

First morning woke up, jumped in the shower and got an elecrtic shock from the metal shower faucet when I tried to turn it off!

I don't know much about domestic electrical work but I assume that this is not normal! I suppose they haven't grounded the plumbing, but how could I check? What should I look for?

[Crossy]

quiksilva, on 2007-04-23 17:51:54, said:

Just brought a place from Sansiri and moved in over Songkran.

First morning woke up, jumped in the shower and got an elecrtic shock from the metal shower faucet when I tried to turn it off!

I don't know much about domestic electrical work but I assume that this is not normal! I suppose they haven't grounded the plumbing, but how could I check? What should I look for?

HI QS. Rather than cluttering this poll with Q&A's have a look here http://www.thaivisa....showtopic=67644

I'll quote this thread over there so you get your answers

Number one, start taking cold showers

[maprao]

bronco, on 2007-03-31 14:46:17, said:

Does any one realise that a capacitor represents a short circuit to AC?

mmm well actually depends on the value of the capacitor. The formula for Capacitive reactance is Xc=1/2πfc .Capacitive reactance is the electrical resistance the capacitor has on the circuit.

Xc = Capacitive reactance (resistance to AC)
π= 22/7 OR 3.14 (pye)
f= frequency of mains electricity 50Hz or 60Hz Depending on country
c= value of the capacitor in Fahrads (unit of measure of capacitance)

Therefore a capacitor of the correct value would present a high resitance at the mains frequency. Again why only qaulified people should get involved in any electrical installation. Me I will still stick to drinking chang beer and pay an electrician to do the work:-)

Edited by maprao, 2007-05-02 23:13:25.

[chanchao]

That's three no's for me.

On the third question I would perhaps welcome supervision of a qualified PERSON, but I don't give a hoot if he/she is foreign or not. Rather not, actually.

[bazmlb]

All of the flouros in my place were wired to switch neutral, makes a great glow when they are turned off at night and really annoying, some didnt work as the twist joins had started to corrode or become loose

[chownah]

bazmlb, on 2007-06-02 23:51:41, said:

All of the flouros in my place were wired to switch neutral, makes a great glow when they are turned off at night and really annoying, some didnt work as the twist joins had started to corrode or become loose

This is not a big problem....if all on one circuit are switched on the neutral then just reverse the polarity at the breaker box....what?....you are worried that the wire colors will not be appropriate?....guess what!!!....in Thailand you should ALWAYS assume that the colors are meaningless because quite often they are....you should always check and never assume polarity of any circuit in Thailand....that's what Thai electricians do. If it still bothers you then make notes on small pieces of paper saying CAUTION...REVERSED POLARITY and put one in each of the switch boxes and light fixtures and junction boxes.

Of course this is just the rice farmer approach....and as you well know all us rice farmers are luckless and clueless.....

Chownah

P.S. You might be able to just swap the wires in the switch box...or the fixture...or something like that but being clueless...and lazy...I'll not suggest how this could be done.

Chownah

[bazmlb]

chownah, on 2007-06-03 02:13:31, said:

bazmlb, on 2007-06-02 23:51:41, said:

All of the flouros in my place were wired to switch neutral, makes a great glow when they are turned off at night and really annoying, some didnt work as the twist joins had started to corrode or become loose

This is not a big problem....if all on one circuit are switched on the neutral then just reverse the polarity at the breaker box....what?....you are worried that the wire colors will not be appropriate?....guess what!!!....in Thailand you should ALWAYS assume that the colors are meaningless because quite often they are....you should always check and never assume polarity of any circuit in Thailand....that's what Thai electricians do. If it still bothers you then make notes on small pieces of paper saying CAUTION...REVERSED POLARITY and put one in each of the switch boxes and light fixtures and junction boxes.

Of course this is just the rice farmer approach....and as you well know all us rice farmers are luckless and clueless.....

Chownah

P.S. You might be able to just swap the wires in the switch box...or the fixture...or something like that but being clueless...and lazy...I'll not suggest how this could be done.

Chownah

swapped them at the switch as thats where the power feed ends, they dont go to the light then run a pair to the switch as in australia, and some lights were wrong and some right so just changed the ones needing it at the switch

[frikkiedeboer]

elkangorito, on 2007-03-30 15:20:02, said:

The questions are self explanatory. If possible, please give reasons for your choices. Please cite 'real' cases & not 'stories'.

when i first came to thailand, stayed at the inlaws' place, and one night the lights fused. i looked for the cause, found nothing , and replaced the fuse with a new one. next night, the fuse blew again, and they called the "electrician" in. he did not even consider that there could be a fault/overload, and simply wound a length of thick copper wire between the two contacts, said to me: "copper, velly good!" i tried to explain to him that this was not a "velly good" solution, but he, and the rest of the family laughed at my ignorance,-after all, he had solved the problem, and my attempt (replacing the fuse with one of the correct amperage) had failed. i gave up trying to explain, and just assumed that the electrician was one of those ameteur village handyman types.
this fellow (he lived next door) then disappeared off the scene for about six months. one day he arrived back, and i asked him where he had been all this time. he said he had been employed on site at the new airport building. i asked him what kind of work he had been doing, and he replied that he had been employed as an electrician!- scary stuff!
i have no doubt that there are properly trained and qualified thais who are perfectly capable of doing a competent job, but only too often, building contractors will hire somebody off the street, with limited knowledge/ability, and the homeowner,is left blissfully living in a death-trap.there seem to be no proper controls and checks in place. at my place, (and i wired it myself),the electricity dept. came to "inspect" the installation before wiring up the meter. all they checked was the overhead cable to my distribution board, then signed it off. the inspector explained to me that as long as there was a single fuse box (doubling as an isolator) between the house and the supply, he was happy.
be scared......................

[elkangorito]

I was at a friends place in Klaeng when a rather nasty electrical storm occurred. After the storm had gone, one of the neighbours arrived to seek electrical assistance - they had power & only partial lighting. Since I had my electrical tools with me, I checked it out for them.
After doing the usual checks at the distribution board (correct voltage, correct CB operation, appropriate circuit isolation etc), I discovered that this particular lighting circuit had some strange resistances and voltages between active & neutral. Because the system was not MEN (& consequently unearthed), I was unable to test comparative earth to active & earth to neutral voltages/resistances. I did, however, decide that the storm had damaged the ballasts in some lights & quite possibly the starters too. I instructed the occupants that it would be a good idea to replace the light fittings because a faulty ballast can get very hot & start a fire. I then went away to procure the appropriate equipment.
Upon my return, I found all lights blazing. I discovered that a Thai friend (of the occupants) had been & replaced the starters in my absence. The ballasts were not replaced.

Obviously the words electricity', 'fire' & 'dangerous' mean very little to many people here...or is it an ego thing to 'show up' the farang?

In any case, I believe that all the light fittings have now been replaced because another storm completely destroyed them & even the usual universal Thai electrical band-aids could not fix them.

[Gimbo]

gcad, on 2007-03-30 19:13:19, said:

-Ability to insert plugs upside down, ie. No care for polarity.
-

It's AC/DC and thus you do not have to consern yourself with that.

Else, most electrical domestic installations I have seen in Thailand are a hazard to life and limb. I am a trained electrician, and and any inspector from north of the Brenner pass would have heart attack if he saw some of the stuff in Thailand

[Gimbo]

chownah, on 2007-06-03 07:43:31, said:

. If it still bothers you then make notes on small pieces of paper saying CAUTION...REVERSED POLARITY and put one in each of the switch boxes and light fixtures and junction boxes.

Of course this is just the rice farmer approach....and as you well know all us rice farmers are luckless and clueless.....

Chownah

P.S. You might be able to just swap the wires in the switch box...or the fixture...or something like that but being clueless...and lazy...I'll not suggest how this could be done.

Chownah

You have to be pretty fast, as AC/DC current switches polarity constantly at 50 or 60Hz, thats 50 or 60 times a second. Thats why it does not matter what way you insert a plug into an electrical outlet.

What you should worry about is overloaded wiring, not dimensioned for the load, and short circuits, and not to mention earth being directly connected to one of the live wires, and carrying a current...

[paulsmithson]

Just bought a house here---many considerations amongst them basic electrics. \looked for an earth rod and found it---checked that the earth wire ran to the distribution board---it did, Paid the cash and moved in then started installing a few aircon units and wiring them into the panel. That is when I found out that the only thing earthed was the disi-board itself!!!!!Earth wire in but no earths running out.

Earthing has been a requirement of the Thai electrical authorities her for over two years now. the builder obviously knew this and blagged it!!!!!!!!!!!!!!!!!!!!!!!!!!Easy answer---I shall run the earth wires asap.

I do know many very competent Thai electricians and respect them.

[chownah]

Gimbo, on 2007-07-21 22:51:02, said:

chownah, on 2007-06-03 07:43:31, said:

. If it still bothers you then make notes on small pieces of paper saying CAUTION...REVERSED POLARITY and put one in each of the switch boxes and light fixtures and junction boxes.

Of course this is just the rice farmer approach....and as you well know all us rice farmers are luckless and clueless.....

Chownah

P.S. You might be able to just swap the wires in the switch box...or the fixture...or something like that but being clueless...and lazy...I'll not suggest how this could be done.

Chownah

You have to be pretty fast, as AC/DC current switches polarity constantly at 50 or 60Hz, thats 50 or 60 times a second. Thats why it does not matter what way you insert a plug into an electrical outlet.

What you should worry about is overloaded wiring, not dimensioned for the load, and short circuits, and not to mention earth being directly connected to one of the live wires, and carrying a current...

I'm not so fast...actually I'm kind of slow....but it doesn't matter because the polarity I was speaking of was the polarity of the wiring and by this I meant that the colors of the wires are reversed relative to the proper usage...i.e. the hot and neutral wires have the opposite color from what is proper....I forget which way is proper so I won't even make a guess at it.

I pretty much agree with you about what are the important points to worry about but if you read some of the old posts or stick around here long enough you will discover an entire army of expats who worry alot about alot of other electrifying issues!!! Now that I've made fun of them I want to point out to their credit that they are willing to go to almost any length to resolve their issues and find the proper resolution...or at least a safe one... and in the process we all benefit by learning the proper way to stay safe....don't forget...safety first.

Chownah

[elkangorito]

Gimbo, on 2007-07-21 22:40:06, said:

gcad, on 2007-03-30 19:13:19, said:

-Ability to insert plugs upside down, ie. No care for polarity.
-

It's AC/DC and thus you do not have to consern yourself with that.

Else, most electrical domestic installations I have seen in Thailand are a hazard to life and limb. I am a trained electrician, and and any inspector from north of the Brenner pass would have heart attack if he saw some of the stuff in Thailand

Where did you do your 'electricians' training, Gimbo? By the sounds of things, you did it in Thailand because any electrician with any idea of safety, knows & completely understands that 'polarity' is very important. Failure to respect 'polarity' can lead to death or serious injury (unless of course you did your training in Thailand).

Edited by elkangorito, 2007-07-23 10:39:17.

[Gimbo]

elkangorito, on 2007-07-23 09:03:54, said:

Gimbo, on 2007-07-21 22:40:06, said:

gcad, on 2007-03-30 19:13:19, said:

-Ability to insert plugs upside down, ie. No care for polarity.
-

It's AC/DC and thus you do not have to consern yourself with that.

Else, most electrical domestic installations I have seen in Thailand are a hazard to life and limb. I am a trained electrician, and and any inspector from north of the Brenner pass would have heart attack if he saw some of the stuff in Thailand

Where did you do your 'electricians' training, Gimbo? By the sounds of things, you did it in Thailand because any electrician with any idea of safety, knows & completely understands that 'polarity' is very important. Failure to respect 'polarity' can lead to death or serious injury (unless of course you did your training in Thailand).

Polarity, as in + and - is only important when you are dealing with DC (Direct Current). Electrical installations in houses uses AC/DC. And switches polarity at a speed of 50-60Hz. Thus it does not matter what way you insert a plug.

[Crossy]

Gimbo, on 2007-07-23 15:30:22, said:

Polarity, as in + and - is only important when you are dealing with DC (Direct Current). Electrical installations in houses uses AC/DC. And switches polarity at a speed of 50-60Hz. Thus it does not matter what way you insert a plug.

Ah but it DOES, although we have alternating voltage so + & - don't matter, we have a Live and a Neutral pole (live bites, neutral [usually] doesn't as it should be grounded).

Mostly it doesn't matter with modern appliances which pole is which, but live chassis TVs (still some made like this) and lights with single pole switches can become hazardous if not plugged correctly. Having a two pin plug on a light can also put the live pole on the outer screw part of the fitting ready to bite the unwary inserter of a new lamp, always pull the plug before replacing a lamp.

Edited by Crossy, 2007-07-23 15:45:45.

[Gimbo]

Crossy, on 2007-07-23 14:13:45, said:

Gimbo, on 2007-07-23 15:30:22, said:

Polarity, as in + and - is only important when you are dealing with DC (Direct Current). Electrical installations in houses uses AC/DC. And switches polarity at a speed of 50-60Hz. Thus it does not matter what way you insert a plug.

Ah but it DOES, although we have alternating voltage so + & - don't matter, we have a Live and a Neutral pole (live bites, neutral [usually] doesn't as it should be grounded).

Mostly it doesn't matter with modern appliances which pole is which, but live chassis TVs (still some made like this) and lights with single pole switches can become hazardous if not plugged correctly. Having a two pin plug on a light can also put the live pole on the outer screw part of the fitting ready to bite the unwary inserter of a new lamp, always pull the plug before replacing a lamp.

Sorry, but English is not my first language, so may I try to see if I understnad you correctly.

I think you are misunderstanding the whole polarity bit. In a standard two pronged plug, f.ex the one to a simple desk lamp, both wires is live. There is no neutral pole per se, as the polarity of the two conection points alternates at 50 or 60Hz (depending on the standard in the country).

In a 3 pronged plug, like the britthish are using for everything, the 3rd prong is the earth (grounding, neutral, whatever you call it). This attaches the apparatus to the grounding system of the building.

In Europe (except brittain I think), grounding is only required in wet rooms, like the bathroom and kitchen. Two pronged plugs is the standard. Of course you are not even allowed to move into your house, before your electrical installation have been checked and deemed safe. In Thailand, it's another story...

[Crossy]

Gimbo, on 2007-07-23 16:06:29, said:

In Europe (except brittain I think), grounding is only required in wet rooms, like the bathroom and kitchen. Two pronged plugs is the standard. Of course you are not even allowed to move into your house, before your electrical installation have been checked and deemed safe. In Thailand, it's another story...

OK, I understand the English is not your first language.

BUT

The Euro standard 'Shuko' plug is NOT a two prong plug. It may have only two pins but the third (ground) contact is made by two side connections, except in France and Belgium where a third pin is actually incorporated into the socket, this mates with a hole in the plug and effectively polarises the outlet making it non-reversible

Which Euro country are you from, the standard varies all over the place.