Electrical Vocabulary In Thai

[Crossy]

Good info there Pib, from a respected source (ABB).

I think I'm going to add a differential mode SPD to my existing 2 pole device, cannot hurt

[Sheryl]

Pib, it looks to me liek what the c=b rochure is showing are individuakl SPDs for individual circuits rather than a "whole house" SPD? In any

As in the whole of Thailand I have been able to find exactly one place that sells whiole houser SPDs I didn't have a whole lot of choice! These are the specs of what I was able to get (which is same thing it is replacing). Do they look OK?

Electrical system single phase

Nominal voltage 220 or 240 Vac

Frequency range 45 -65 Hz

Protection Mode L-N, N-E, N-E

Application Range MCOV 180 - 280 Vac

Let through voltage 600V

Surge Energy Dissipation 3080 joules

IMAX 40 kA

Leakage current <120 ua (not really u, but the u-like symbol)

Transient response time <25 ns

Design regulation TVSS standard ANSI/IEEE C62.41-1991, ANSI/IEEE C62.42-2000

3 other questions:

1. When the electrician installed it he did not put it on its own circuit breaker (which the original had been). he told me thios only after the work was all done and insisted that this was the best way. So it is only on the main. Is this worth worrying bout/trying to change? (which will not be easily accomplished so I don't want to if I don't have to)

2. As mentioned the house was wired with no grounding and the ground added afterwards. What was added was a ground from the main circuit board area. However all the individual outlets and connections are just 2 wires. I suspect taht should ideally be changed but also that it would be a huge job, or am I wrong?

3. Unrelated matter but long standing irritant -- all my fluorescent lights glow at night when off, and do so even if the circuit they are on is shut off. After innumerable local changs told me this was "normal", it was finally explained to me by an expat sparky that this is because when connected the lines were reversed, that it was not harmful or dangerous and that to fix it they would all need to be rewired. Is all this correct? And would the rewiring be something that would have to be done up in the roof or is it just a matter of switching the wires at the ballast, which even I could do? The lights in the bedroom especially are very annoying, enough to interfere with sleep. For some reason the glowing starts only around 1 AM and gets progressively brighter as the night progresses, and is much worse in the rainy season.

[citizen33]

I had a similar problem with glowing fluorescent lights after a local tradesman did some work on the house while I was away, and reversed the lines into the house at the meter. In my case I just replaced the wires in their original positions. I wouldn't have thought you need to do anything more than get phase and neutral in their correct positions, but the fact that all the lights are the same might suggest that the problem is at the distribution box (UK language = consumer unit) rather than the ballast on each light. Presumably the lights are on one or perhaps two radial circuits (i.e. a series of lights in a line rather than a ring), and you would just need to identify which MCBs are involved and look at the connections. I always think it is nice to have the colour coding right, so somebody really needs to look at your installation with a meter (presumably grey is phase and black is neutral). Even a humble neon tester will tell you which is phase. So I guess logically you start with your mains supply coming in and verify that everything is the right way around at each stage. It would make sense to look at the sockets too. If you stick the neon screwdriver in the shorter hole it should light. If you do any provisional testing yourself (beyond the neon tester) make sure the power is off. Depending on the wiring the light switch probably won't remove the power to the connections within the lamp. Also if the MCB (which is a single pole switch) has been incorrectly wired so that neutral rather than phase is flowing through it, switching that off will not save you from a shock from phase to earth. So if fiddling with the lights switch off the main supply.

The fact that the ground was not taken from the distribution box to individual sockets probably just reflects how tricky it was to add an extra wire to the original dual core cables. It isn't easy even where you can get inside the ceilings to shove a single core down an existing pvc conduit pipe, so the ground wire probably has to be run on the surface which doesn't look good. In the circumstances it is probably best to concentrate on the shower (essential), washing machine and sockets where you use a desktop PC. It may be neater to take the earth wires from the appliance/sockets straight outside the house and connect direct to the ground spike rather than the distribution box.

I think most of us have had problems with our local chang fai or chang fai fa (as they say in my village), but I have noticed some who have worked for a few years in the middle east are actually not too bad.

Edited June 4, 2012 by citizen33

[Crossy]

Note for Citizen33. Thai wiring (like the US) is Black = Live, White/Grey = Neutral.

Sheryl, if the fluoros are glowing even when their MCB (breaker) is off I suspect your whole house is reverse polarity. This is not a situation which you should be in.

Do you have a 'Neon screwdriver'? If not go and buy one, you put your finger on the metal cap and touch a contact, if the neon glows then the circuit is live.

Your neon should glow when you touch the live side of your beakers and not glow on the neutral connection.

[citizen33]

Oopps! Thanks. In my experience Thai village electricians may do things either way so one needs to check with a meter. In any event I had been trying to make the same point that probably phase and neutral have been switched somewhere further upstream from the lights and might affect sockets etc too.

Edited June 4, 2012 by citizen33

[Pib]

Sheryl,

The surge protector specs look fine.

The surge protector should be on its own circuit but it's OK to share it with another circuit...that is the protector's Line (Live/Hot) wire hooked to say a circuit breaker that feeds a certain circuit/area in your home. Since my main circuit box is full I have my external surge protector hooked to the 16A circuit breaker that feeds my stove hood fan and one outlet in my outdoor kitchen area. A surge protector of the size (I.e., Imax 40KA) you bought should be on a 15-16A circuit breaker to take advantage of its full surge capacity capability...basically you don't want the circuit breaker to trip too easily while it allows a lightning surge to pass through it on it's way to the surge protector which will clamp the surge voltage/divert a good portion of the surge. If say it was hooked to a 5 or 10A circuit breaker the breaker would probably trip before the surge protector completed its job of handling a big surge and the next lightning surge that might be following right behind it since passing thunderstorms are normally throwing down multiple lightning bolts as they pass over. Now if it's hooked to the output side of your mains breaker I hope the breaker ain't too large, like the 80A main in my 100A service home, because if the surge protector does not have good over current protection built-in an 80A main circuit breaker would probably just continue to allow current to flow and the protector to melt itself...or the main breaker does trip and you are left in the dark for the whole house. Up to around 50A is the largest circuit breaker that should be used like if having a really big Imax protector, say 100KA or over. Additionally, the wires hooking the external surge protector to the main circuit box should not be any longer than 0.5M, preferably no longer than 0.25M. Longer connection leads allow part/a higher voltage level of the lightning surge to continue all down your individual circuit lines before before the surge gets to the surge protector and is dealt with.

Yeap, to get a 3 wire (L, N, E) hookup to all your outlets, with the Earth/Protective Earth wire running back to your grounded main circuit box, you need three wires feeding 3 hole sockets...that could be hard running new wiring and expensive depending on the construction of your home.

Regarding your fluorescent lights continuing to glow slightly after your turn them off sure sounds like the 220V is not being cut to the lights whenever you turn off the light switch....that is, the light switch is in the Neutral line versus the Hot line. Or, like Crossy said the Line and Neutral are hooked up backwards at the main circuit which would have the same effect as the light switches being in the Neutral line. I'm assuming your Earth wire that is hooked into your main circuit box is hooked to the Earth bar and the Earth and Neutral bars are "not" connected together...because if they were connected together and the wiring was backwards your main box would have smoked itself upon initial hookup. Do the check Crossy recommended....if the main box wiring is not reversed then your light switches are probably hooked in the Neutral line versus the Hot line. With the hot wire still feeding voltage to one end of the tube with the switch turned off there is probably enough of a electric field on one end of the tube combined with residual current leakage to cause the tube to continue to glow faintly. And the reason it seems to glow brighter in the middle of the night is because most people are in bed and the electrical loading in your area has been reduced which allows the line voltage feeding your house to rise to a higher voltage. And with it getting worst during the rainy season that could be due to people turning off/unplugging a lot of their electrical devices until the storm passes which reduces the area voltage loading...and the voltage rises. Plus, in rainy season with humidity and wetness residual/fault current leakage is more likely.

Cheers,

Pib

[Sheryl]

Pib, it's not on any circuit, it's directly on the main. The main breaker is marked 100. So I gather not good. Just how bad is it? (i.e. how urgently do I need to try to get someone in to change this - which will not be at all easy??)

Crossy, I feel like an utter idiot (and am when it comes to matters like this, alas -- only in the DIY forum out of desperation, would gladly not do it myself in any way had I a real choice) but I need you guys to explain more clearly exactly where I should put the tester. What contact/ where?

[Pib]

Sheryl,

Wow...a 100A main breaker. Are you on a 100A service/electric meter? Normally the main breaker size chosen is around 80% of the main service. Like for me, I'm on a 100A single phase sevice/100A meter and I have a 80A main breaker in my main circuit box. For some reason I assumed you were probably on a smaller service like maybe around 30A,or 63A (or maybe even smaller). What does your electric meter say on it regarding its service amps...it will say on a label/plate on the front of the meter...look for something that might say something along the lines of (5)15A which would be a 15A service, (30)100A which would be a 100A service, etc.

Your external whole house surge protector should be on it's own dedicated circuit breaker...not absolutely required but "should" be for safety and surge capacity purposes. But if all of your circuit breaker slots are full then hook it to one of those breakers in the 16A or 20A ballpark...even a 32A would be OK but I wouldn't go over 50A. And pick a breaker location as far left in the box as possible (close as possible to the main breaker) to maximize the surge protector's ability to deal with the surge just as soon as it passes the main breaker. You should pick a lightly loaded breaker because if say a 20A breaker is normally carrying around 15A due to items hooked to it all the time, that only leaves 5amp reserve on the breaker for the surge protector when it must deal with surges. You want the breaker chosen to have around 15A or a little more reserve current capacity to use the protector's full surge capacity.

Cheers,

Pib

[Crossy]

Like Pib, I'm a bit worried about your 100A incomer. Please post a photo of your meter (close enough that we can read the text).

Whilst you're at it post a photo of your distribution board with the lid off (care please), we can then show you where to poke your neon and what result you should expect there.

The breaker for the SPD is there so that in the event the SPD fails short-circuit you don't kill all power to your home or (worse) don't kill the power to the SPD at all resulting in a fire.

[Sheryl]

My understanding is that I have 30A coming into the house, it was built with much less and I had to pay the electric company to come and change it. the meter says 30 but then in parenthesis 100. ??

Now regarding the main breaker. I forgot to mention that I actually have 2, there is one located right outside the house and then the one at the main circuit board. The main circuit board one is 100 but the one outside the house (which AFAIK is thus between the meter and the circuit board i.e. current passes through there first) is rated 50. The reason for the additional one outside is that it was supposed to have been a SPD and indeed more over a year that's what I assumed it to be (told you I'm an idiot when it comes to these things!). At that time I had the whole house on an expensive stabilizer that kept shorting out (usually a week or so after warranty expired) so I asked to put in something that would block surges to it i.e. an SPD and this is what the "chang" then gave me instead. I eventually learned it was not an SPD and got an actual SPD installed but the 2 main breakers remain.Here are pics of each:

Breaker Outside the house:

Main Breaker on Main Circuit board:

Now here are pics of the circuit board with cover off, one straight on and 2 side views since I have no idea what exactly you need to look at. Looks like an intimidating mess to me.

There is a free circuit not being used for anything (blue tape), used to be where the SPD was.

[Pib]

You have a 100A service/meter. Just as FYI, the 30 that next to the 100 just means 30A is used as a calibration/test point.

That 50A breaker between the meter and your main box could be considered an isolator breaker in that it would allow the power to be turned off from outside your house normally during an emergency like the house is on fire and you/the fire dept wants to kill the power before spraying water on the house....and of course it would possibly come in handy in some other cases. Now when saying isolator it does not isolate/block any surges...it just allows the power between the meter and house to be cut off (isolated) from the outside of the house. I don't know if that isolator breaker should normally be a 100A to match the meter or something a little lower. But with that 50A preceding the 100A main breaker, you effectively have a 50A limit coming to your house....kinda like having a 50A main breaker.

Since I see 4 wires running to your 100A main breaker input on the bottom of the breaker , I'm assuming maybe the grey and red wires are surge protector wires since it looked like two black wires were running from your isolator breaker into your house 100A main breaker were both black and I think I see two black wires connecting to the input of your 100A breaker. Although you do have a 50A isolator breaker in front of the surge protector he really shouldn't have connected the surge protector there; he should have connected it to that 20A breaker marked with the blue tape (assuming the breaker is still good...if bad a replacement would only cost around 150 baht) as that would have provided a "dedicated" breaker for the surge protector. And since you have a couple of open breaker slots close to the main breaker where power is first coming into your house, it would be better to put/move the dedicated breaker to one of those open slots. Plus, the surge protector was to smoke itself again it could possibly trip the 50A isolator breaker feeding power to your whole house; if it was on that 20A breaker it would just trip that breaker and kill power to the protector only...plus 20A is real close to the proper breaker size for that surge protector....not 50A.

And I sure hope the surge protector is mounted just outside/real close to the main box otherwise the long lead length between it and its power connection point will greatly degrade its effectiveness....the leads should be no longer than 0.50M and preferably 0.25M or less.

[electau]

The meter is rated at 100A continuous. The main switch should be rated to the current rating of the incoming consumers mains, these should be 63A minimum. The main switch is a MCB which has overcurrent and short circuit protection for the mainswitch board on the load side of the MCB and the line side of the MCBs supplying the subcircuits. The reason that an MCB is used as a main switch is that there is no protection on the consumers mains from the meter, for some unknown reason the PEA/MEA do not install a protective device on the line side of the meter. This is normally an HRC fuse, and is supplied and installed by them. This protective device is for short circuit protection and a point for disconnection of supply.

The surge protector SPD should be connected to an MCB as a final dedicated subcircuit, if the SPD was to fail ( short circuit) the MCB would clear the fault first.

( Short circuit currents at a switch board can be high compared with normal tripping current of a MCB and depend on the size of transformer and the impedance of the conductors.

Short circuit currents can cause severe damage to equipment with arcing and burns to a victim. Electrical work should never be carried out with equipment energised, test before you touch.)

For a MCB as a main switch the rating should normally be 10kA for 220/240V and 6kA for 380/415V. Your existing Square D MCBs comply. The subcircuit MCBs are probably rated at 5kA./220V.

An MCB also fixes the max demand in amps for an electrical installation.

Reversal of polarity will not occur if correct testing procedures are carried out before connection of supply or when additions and alterations are carried out or metering is replaced.

One should never rely on colours of cables alone. The incoming mains neutral conductor should be suitably identified using sleeving, markers or other suitable method.

Edited June 5, 2012 by electau

[Sheryl]

The SPD is located not more than a foot away from the main circuit board so no problem on that front.

Pib, y our explanation of the 2 main breaker situation is what i had thought. Oddly though that 50 A breaker has never tripped that I know of.

So I gather that as far as surge protection goes, all is well except that i need to get the SPD put onto a circuit.

Now what is left besides that (and the challenge of finding someone capable of doing it) is the polarity issue. Where exactly am I supposed to test for presence of current?

Electau - I can guarantee that "correct testing procedures" were not carried out when this house was originally wired. Not much of correct anything, in fact. And I have been told by an expat sparky that a reversal of the L and N wires is the reason for the fluorescent light problem. I had the impression he was saying this was a problem with the lights only but that may have been an assumption on my part. He seemed to feel that fixing it would be difficult and time consuming and I couldn't get him to do it.

[Pib]

Now what is left besides that (and the challenge of finding someone capable of doing it) is the polarity issue. Where exactly am I supposed to test for presence of current?

I would first confirm the two incoming black wires to the bottom of the 100A main breaker are wired up correctly to you main 100A breaker polarity-wise...these are the two wires coming from your 50A breaker outside.

The Line (a.k.a., Hot, Live, Phase, the one with 220V on it) must be connected to the right bottom, right hand side connector of the 100A breaker. In fact, if you look on the panel underneath the main breaker/incoming wires you should see the letters N and L which identifies that the incoming Neutral wire is to connected to the N connector on the breaker and the incoming Line wire is connnected to the Line connector on the breaker.

You may want to buy yourself one of those small screw driver looking electricial testers (they cost less than 100 baht) which looks like a screw driver with a light in its handle/grip...sold in many places. When the tester's tip touches or is brought close to a wire with voltage on it, like your Line wire carrying 220V it will light up; put that same tester on or near the Neutral wire and it shouldn't light up (although it may glow very faintly depending on any leakage currents you may have).

If this wiring polarity is correct then the polarity is correct to the main breaker which will also mean the Neutral is feeding through the main breaker to the Neutral bar just left of the main breaker and Line is feeding down a metal bar to the top backside of the individual circuit breakers...you can see parts of that metal bar where those open breaker slots are. Then the Line voltage feeds through the breakers to the wires at the bottom of the breaker...and these "hot/220V" wires continue to your outlets, switches, light fixtures, etc. Basically this means the breakers are in the "high/live/220V" side of the line which is correct.

OK, if the main box checks out polarity wise then the wires leading to your lights may have the light switches in the wrong line. Just try to envision only two wires running to your lights from the main breaker box...one wire is hot and one wire is neutral...the individual wall mounted switches for the lights need to be hooked into the hot wire; not the neutral wire. If the switch is hooked into the neutral line when you turn the switch off it breaks the current path and the light turns off; however, but, with the hot wire still applying 220V to one end of the tube this can cause enough of an electric field on the end of that tube to cause it to continue to faintly glow. But if the light switch was in the hot line when you turned off the switch it cuts off the 220V at the switch, that 220V is not reaching one end of the tube, and the neutral connection on the other end of the tube is pretty much at zero volts....so, the tube won't have have any voltage potential across it, zero volts on both ends, and it won't have a faint glow. If it continues to glow then there are other issues/possible causes such as maybe living directly under a high voltage line, next to a high voltage transformer, etc., and the electric field from these high voltage sources is causing the problem. I doubt you are living next to any of this stuff...a person couldn't miss seeing such electrical lines/transformers.

Something you might want to try tonight for a few minutes is with the lights turned off and getting that faint glow turn your main breaker off which will kill power to the whole house, the lights, everything...it cuts the connection on both the Line and Neutral wires leading to everything. If the light glow goes away after a few minutes then it's not a problem with a high voltage electric field from an overhead high voltage line, very close high voltage transformer, etc., which I doubt is the case. But this would help to confirm you most likely got a wiring polarity problem which may require simple or not-so-simple rewiring of your main box and/or light switches. Good luck.

[Crossy]

Yes PIB ^^^.

Note to Sheryl. Those neon testers are very handy. To use you put your finger on the metal cap and touch the circuit you want to test, if it lights, it's live.

Note. Since you are actually part of the circuit (the neon lights because you provide a path to earth), it is essential that you keep your tester is good condition, particularly don't let it get damp. There is an anecdote involving an sparkies apprentice who dropped one in a bucket of water, dried it off and returned it to the toolbox. The result when sparkie next used it is obvious

[Sheryl]

Just to be clear here, where exactly am i supposed to put the test probe? When you say "touch the circuit" what part exactly do I touch? The outside of the insulated wires is obviously not going to show anything so you must mean elsewhere but I don't want to mess about until I'm sure I know where.

And is it possible to do this with a 2 probe voltage meter? (As I already have one of those. -- thing with a red probe and a black probe ) In which case do I apply both probes (red and black) to the same place and if so again, where exactly? And what setting do I put the voltage meter on? It has a range of settings from 0.1 - 1000 DCV whatever that is.

[Pib]

Just to be clear here, where exactly am i supposed to put the test probe? When you say "touch the circuit" what part exactly do I touch? The outside of the insulated wires is obviously not going to show anything so you must mean elsewhere but I don't want to mess about until I'm sure I know where.

And is it possible to do this with a 2 probe voltage meter? (As I already have one of those. -- thing with a red probe and a black probe ) In which case do I apply both probes (red and black) to the same place and if so again, where exactly? And what setting do I put the voltage meter on? It has a range of settings from 0.1 - 1000 DCV whatever that is.

Yes, it's possible, even better, to do it with a multimeter...what you are calling a 2 probe voltage meter.

Set the multimeter to measure AC voltage, not DC voltage. Hard to tell from the picture but it's probably the red colored area on the meter's switch...usually with a little sine wave mark next to the letters AC. Select a range that can measure at least 250VAC...you don't want to peg the meter like setting it to say the 50VAC range and then measure 220VAC...just pegs the meter/over-ranges the meter.

Touch the black lead to the Earth bar (the case of the main box) and then the Red lead to the terminal you want to measure like those incoming leads from your 50A breaker to the 100A breaker. When you get a reading of approximately 220V that means it's a hot/live line; measure the other incoming line and it should only be a few volts or less...something pretty close to zero volts...that would be your neutral line.

With that tester mentioned earlier you don't need to actually touch an uninsulated point...you can also just bring it real close to the insulated wire or even touch the insulation with the probe tip...it will pickup induced voltage. As Crossy mentioned, your body then provides enough of a return path to earth to make the little neon light come on if voltage is detected.

[Sheryl]

OK, I did it. Results: the main breaker inside the house is OK, the bottom lower right wire is the hot one and the one to the left is neutral.

But at the breaker outside the house (the insulator) it is the opposite -- the left is hot and the right is neutral.

So am I right in assuming this means that when the insulator was installed, its polarity was reversed? And that this potentially explains the problem? It does make some sense as the problem was not present when the house was first built, developed later, so maybe that was the precipitating factor. I didn't make the connection at the time (no pun intended) but it might have been after the insulator was installed that I started to notice the problem.

If so, what needs to be done to correct it? Obviously, switching the wires to where they should be on the insulator but I am wondering if after doing that they will also need to be switched at the main breaker inside the house? (since the wiring coming in had been crossed, does uncrossing it make the current sequence crossed? Hope you know what I mean).

[bankruatsteve]

Not to butt in... but if you're looking for a quick response... the outside breaker SHOULD be hot on the left and neutral on the right. So, that's good. (It's not a left/right thing but a "Line" and "Load" = voltage).

If the cables are correctly sized for 100a, you could eliminate the 50a breaker (just connect the wires together inside the box). Chances are you will never exceed 50a anyway and perhaps you would have done just as good with a 15/45 meter. But, that's did and done.

Hope you getting close to mellow.

[Pib]

That's good to hear that your main circuit box is wired corectly polarity-wise. And that ouside breaker is also OK since the Line voltage comes in and out on the left side per its polarity markings...it's OK polarity-wise also.

Now you are getting closer to hopefully resolving your florescent lights problem. You might want to try turning off the main breaker like dicussed above, but actually you don't even need to do that now since the polarity to the main box has been confirmed. Just turn off one of those sub breakers that feeds an area/room with lights....like that bathroom light you said had the brightest glow when turned off. If the light stops its low glow in that room/area after a minute or so (probably much less than that) then that is still pointing towards that light switches being wired into the neutral line feeding each light versus the hot line. Now depending on how the wiring is run to the lights and switches that could be either an easy/quick or semi-hard job to fix.

P.S. As I'm writing this, here is western Bangkok we are having a thunderstorm with plenty of lightning...in fact the time between the lightning and the thunder is approx 5 seconds which means those bolts are only about a one mile away. The storm is going west to east....heading towards Swampy Airport.

[electau]

Reversal of the L and N conductors can occur at the meter, or at the point of connection to the distribution network or at the main switch board . It will not occur if correct testing procedures are carried out. The main incoming neutral should be clearly identified. Make sure that the neutral conductors terminate at the neutral bar or link.

Polarity reversal is not a fault but a serious defect that must be rectified.

[Sheryl]

That's good to hear that your main circuit box is wired corectly polarity-wise. And that ouside breaker is also OK since the Line voltage comes in and out on the left side per its polarity markings...it's OK polarity-wise also.

Now you are getting closer to hopefully resolving your florescent lights problem. You might want to try turning off the main breaker like dicussed above, but actually you don't even need to do that now since the polarity to the main box has been confirmed. Just turn off one of those sub breakers that feeds an area/room with lights....like that bathroom light you said had the brightest glow when turned off. If the light stops its low glow in that room/area after a minute or so (probably much less than that) then that is still pointing towards that light switches being wired into the neutral line feeding each light versus the hot line. Now depending on how the wiring is run to the lights and switches that could be either an easy/quick or semi-hard job to fix.

No problem when the main breaker is off, but when the circuit that the lights are on is off, they still glow . So what does that mean?

[Pib]

That's good to hear that your main circuit box is wired corectly polarity-wise. And that ouside breaker is also OK since the Line voltage comes in and out on the left side per its polarity markings...it's OK polarity-wise also.

Now you are getting closer to hopefully resolving your florescent lights problem. You might want to try turning off the main breaker like dicussed above, but actually you don't even need to do that now since the polarity to the main box has been confirmed. Just turn off one of those sub breakers that feeds an area/room with lights....like that bathroom light you said had the brightest glow when turned off. If the light stops its low glow in that room/area after a minute or so (probably much less than that) then that is still pointing towards that light switches being wired into the neutral line feeding each light versus the hot line. Now depending on how the wiring is run to the lights and switches that could be either an easy/quick or semi-hard job to fix.

No problem when the main breaker is off, but when the circuit that the lights are on is off, they still glow . So what does that mean?

Wiring/switch issues...maybe leakage currents. What you may want to try on one light, like that bathroom light, is at the light fixture where the Line & Neutral wires comes into the fixture and hookup to fixture wires/maybe a ballast is: reverse those connections. That would be no different than unplugging a two prong electric cord device, rotating the plug 180 degress and plugging it back in. But the wire reversal will change which end of the tube holder the 220V goes to and possibly ballast loading conditions which may affect the glow. Your ballast is still in the circuit, if the fixture uses a ballast.

[electau]

You should check the polarity at all light switches, they must switch on the line conductor, any ES lampholders must have the switched line to the centre teminal.

The fluor lights most likely glow when switched off because the polarity is transposed.

Black is the line and grey or white is the neutral. Switches must operate in the line conductor only unless the line and neutral are switched simultaneously.

Edited June 8, 2012 by electau

[Pib]

Sheryl,

And if the switching around the connections don't work you could try put an electronic ballasts on your lights which basically works by converting the 50Hz feeding the light to a much high frequency (20,000 Hz ballpark) which eliminates that startup blinking, flickering, etc...this also basically isolates the 50Hz from the bulb...it's also kinda like putting an electronic switch (controlled by your light switch) into the circuit that also converts 50Hz to a much high frequency when turned on.

I know when I bought my house about 5 hears ago all the fluorescent lights were the standard ballast type and when turning them on you got that blinking/flickering during startup that is common with flourescent lights and I just hated....especially when walking into a dark room at night, turning on the light switch, and wanting to look down/close my eyes for a few seconds as he lights started up/did their strobe light type startup thing. Even with the most capable starter the lights would still flicker/blink on startup which is just the electrical nature of most fluorescent bulbs----unless they use an electronic ballast...then they are pretty much instant on like an incandesent bulb. I have changed approx 90% of my flouresent fixtures to electronic ballasts...the other 10% are in locations that are kinda hard to get to so I'm just waiting until I "have" to get to them to change a bad bulb. Electronic ballasts cost in the 150-250 baht ballpark. They are pretty easy and fast to install.

Pib

[Crossy]

Glowing fluorescents when 'off' is invariably a switched neutral. Since it seems the main wiring is the correct way round then the switching needs investigating.

Did you buy a neon? If not go and get one, this test is far easier with one than with a meter.

With the light off check both incoming connections to your light fitting, if it is correctly wired you should see NO glow on the neon. If the neon glows on one or both of the connections then the switch is in the neutral.

A switched neutral is not going to cause a fire or anything similar, it is however a hazard because even with the light switched off the fitting is live and will happily kill you when you are changing the tube. It does really need to be fixed.

Installing electronic ballasts may fix the glow, but there is the danger of introducing a more annoying effect whereby the tubes flash at relatively long intervals (possibly once an hour), I've not seen it with full sized tubes, but it's very common with low-energy lamps even if they are correctly wired.

[Pib]

Not to say it couldn't happen, but I've got at least 10 electronic ballasts installed in my home 30/32W circular-type fluorescent tubes for several years now and never experienced such a flashing problem.

[Crossy]

Not to say it couldn't happen, but I've got at least 10 electronic ballasts installed in my home 30/32W circular-type fluorescent tubes for several years now and never experienced such a flashing problem.

Are they all on switched neutrals??

Like I said, I've not personally seen it on full sized fluorescents but it's very common on CFLs, particularly when they are on two-way switching (stairs lights). It's all down to capacitive coupling charging up the main reservoir capacitor, once it hits a high enough voltage the tube fires once, discharging the capacitor and re-starting the sequence.

[Sheryl]

Glowing fluorescents when 'off' is invariably a switched neutral. Since it seems the main wiring is the correct way round then the switching needs investigating.

Did you buy a neon? If not go and get one, this test is far easier with one than with a meter.

With the light off check both incoming connections to your light fitting, if it is correctly wired you should see NO glow on the neon. If the neon glows on one or both of the connections then the switch is in the neutral.

A switched neutral is not going to cause a fire or anything similar, it is however a hazard because even with the light switched off the fitting is live and will happily kill you when you are changing the tube. It does really need to be fixed.

Installing electronic ballasts may fix the glow, but there is the danger of introducing a more annoying effect whereby the tubes flash at relatively long intervals (possibly once an hour), I've not seen it with full sized tubes, but it's very common with low-energy lamps even if they are correctly wired.

I got the neon but am obviously doing something wrong as it doesn't light up when I touch any part of the fixture even with the circuit on (when it clearly does have current) so I must be touching the wrong place. It is not the tester as it works fine when I try it in for example a socket.

Where on this am I supposed to put the tester? Or was I supposed to disconnect the whole business and touch the incoming wires? I tried where the wires enter the ballast etc but no luck

[Pib]

Not to say it couldn't happen, but I've got at least 10 electronic ballasts installed in my home 30/32W circular-type fluorescent tubes for several years now and never experienced such a flashing problem.

Are they all on switched neutrals??

Like I said, I've not personally seen it on full sized fluorescents but it's very common on CFLs, particularly when they are on two-way switching (stairs lights). It's all down to capacitive coupling charging up the main reservoir capacitor, once it hits a high enough voltage the tube fires once, discharging the capacitor and re-starting the sequence.

Have no doubt it can occur; I just haven't personally experienced it. I've got around a dozen CFLs inside/outside the house and haven't experienced any flashing problems over the last 4 years of living in my house; the only thing I have experienced is they don't last anywhere close to the hours they are rated for and I've tried various CFL brands over the years from the name brands to the cheapies...they all seen to last about the same length of time...seems I'm real lucky to get two years out of CFL...or at least in my house they don't last anywhere close to their rated hours. When one fails it fails to where it don't even try to turn-on...it's just dead...I figure some of it electronic starter/ballast circuitry died versus the little tube itself going bad. Maybe cheap light switches sending too many voltage spikes on each turn-on and turn-off to the light. Before the switch for my front door outside light would make my DVD hiccup every time I turned the light on or off..changed the switch last year and the problem went away...dirty/corroded/sparking switch I figure which was causing a healthy voltage spike. But my regular straight tube/circular tube fluorescent lights which have the separate electronic or standard ballast last a long time. The only place I have a two-way switching is on the stairs and it uses a 32W circular tube type...it's one of those I haven't converted to an electronic ballast yet because it so hard (high up) to get to...and that light has over 4 years under its belt right now.