Re: Dangers With Electrical Appliances In Thailand

[junkofdavid2]

I was cooking on my electrical stove (max is only 1,500 watts) which has low to high... levels 1 to 6.

As I was cooking and decreasing the heat level (from about 4 to 1) there was a tiny pop coming from near the knob of the appliance... and then it was off.

Moreover, other things in my apartment plugged into other power outlets stopped working.

Turned out, circuit breaker tripped.

After switching on the circuit breaker again, everything worked fine again, INCLUDING the electric stove!

To those who know about electricals... what happened?

If a fuse blew in the stove, why was it still working after I reset the circuit breaker?

If it was a short, what could have caused it? (It was brand new, less than a month old... Hanabishi brand which is "reputable" in Thailand)

Couldn't be power overload right? Because stove's max power is 1,500W (if it's on highest level 6) but in this case, it was going from level 4 (about 800w) to level 1 (only 142W)

Any ideas?

Other info:

1) I was using a (cheap) extension cord from Lotus... because the stove's plug isn't long enough to reach the power outlet. However, the extension cord literature says it's safe up to 2,000 watts, which is 500W higher than the stove.

2) It's a stove for cooking... so naturally, liquid may sometimes drip onto the stove (but certainly not a big amount as I'm careful about that, and it should be engineered for that to some extent because it's for cooking!)

Also, is it safe to continue using it?

If any, what are safety precautions I can take?

To those who will suggest going to the service center... yes, I will do that after Songkran. However, I want to know what they're talking about and from my experience at Thai service centers, the person you're dealing with can often be an extremely mentally challenged gentleman; which is okay if he admits he doesn't know, but can be disastrous if he pretends to know just so that he can 'save face'.

Edited April 13, 2008 by junkofdavid2

[lazeeboy]

a cheap extension even though mark high maybe not,if i use my deep fat fryer and shower at the same time it trips,3 phase is whats needed,an electrian just said put a bigger fuse in the box ,go figure

[Tywais]

Actually those stoves don't work at linear power levels, they cycle full power on then full power off in order to maintain an average temperature - that is. its full 1500W then zero. Turning the dial just changes the threshold where the temperature sensor (in these cases a bimetallic strip) turns the heating element on and off.

[GuestHouse]

Some observations:

Your stove is pulling about 6Amps of Current - This is almost certainly too much for your extension cord (Which you ought not to be using anyway - especially as you probably have half the extension cable still coiled on the drum and hence a real fire hazard).

6 Amps may also be too high a current for your Circuit Breaker - so check the breaker and tell us what rating it is.

---

As for your stove. I'd measure how long a power cord you actually need and then take your stove to a local electrical repair shop and ask them to replace the flexible cord for one of the correct length (thus getting rid of the need for an extension cable and removing the fire/electrocution risk that this poses). Make sure that the wires of the cord they fit is at least the same cross sectional area as the cord they remove. If you can choose at the shop, choose a 4 square mm, multi-strand, flixible cable - a heavier duty version of the kind of thing that you might find on a clothes iron or electric hand drill.

When the shop have fitted the new cord get them to test it for you - They ought to use a mega meter to test between the cores of the wires and the metal work of the stove. At the very least they ought to use a resistance test meter (or multi meter switched to its resistance function).

Edited April 13, 2008 by GuestHouse

[junkofdavid2]

Some observations:

Your stove is pulling about 6Amps of Current - This is almost certainly too much for your extension cord (Which you ought not to be using anyway - especially as you probably have half the extension cable still coiled on the drum and hence a real fire hazard).

6 Amps may also be too high a current for your Circuit Breaker - so check the breaker and tell us what rating it is.

---

As for your stove. I'd measure how long a power cord you actually need and then take your stove to a local electrical repair shop and ask them to replace the flexible cord for one of the correct length (thus getting rid of the need for an extension cable and removing the fire/electrocution risk that this poses). Make sure that the wires of the cord they fit is at least the same cross sectional area as the cord they remove. If you can choose at the shop, choose a 4 square mm, multi-strand, flixible cable - a heavier duty version of the kind of thing that you might find on a clothes iron or electric hand drill.

When the shop have fitted the new cord get them to test it for you - They ought to use a mega meter to test between the cores of the wires and the metal work of the stove. At the very least they ought to use a resistance test meter (or multi meter switched to its resistance function).

I think you pointed out something significant.

1) The original cord si 3x1 sq.mm. while the extension cord is only 2x 0.5 sq.mm (despite it saying it's safe up to 2,000W).

How can this cause a circuit breaker to trip, and/or how can it simultaneously produce a tiny pop in the stove?

2) As for the circuit breaker, it seems to say "current 30A" so that should be good right?

3) Assuming I can't replace the flexible cord and I use a new thicker extension cord... is it a good idea to get one with a switch and built in fuse? Does that fuse act as a first defense (pseudo mini-circuit breaker) before a spike from the appliance can reach the room's circuit breaker?

Edited April 13, 2008 by junkofdavid2

[GuestHouse]

I would suggest you replace the Stove Cord with a new cord sufficiently long to avoid needing to use an extension cable.

Installing a fuse would provide additional protection (provided it is rated less than the main breaker - if the breaker and fuse are rated at the same value the breaker will always trip before the fuse blows).

What caused the 'Pop' inside the stove? It could be a fault or moisture - get the repair shop to check it out when you get the cable changed.

[junkofdavid2]

I would suggest you replace the Stove Cord with a new cord sufficiently long to avoid needing to use an extension cable.

Installing a fuse would provide additional protection (provided it is rated less than the main breaker - if the breaker and fuse are rated at the same value the breaker will always trip before the fuse blows).

What caused the 'Pop' inside the stove? It could be a fault or moisture - get the repair shop to check it out when you get the cable changed.

Stove is only a month old and under warranty so I'll have to have it checked at the service center, or else the warranty might be voided. That's actually a pain in the A because those service centers can take long.

Okay, will try to have the cord changed but again, I'm concerned about the warranty of tinkering with the original cord.

So based on your comment about the "pop"... it has nothing to do with the extension cord? In that case, why did it happen simultaneous with the tripping of the circuit breaker? From what I understood from earlier comments, the tripping was likely caused by the lousy extension cord...?

[GuestHouse]

Sorry, I should be more clear.

I mention getting rid of the cheap extension cord because it is singularly dangerous.

[junkofdavid2]

Thanks to Guesthouse for providing very interesting input.

Now, for troubleshooting purposes...

1) Can moisture or fault in the appliance cause the circuit breaker to trip?

If yes, how so?

2) Can a cheap extension cord also cause a circuit breaker to trip?

If yes how so?

[lardy]

a cheap extension even though mark high maybe not,if i use my deep fat fryer and shower at the same time it trips,3 phase is whats needed,an electrian just said put a bigger fuse in the box ,go figure

I heard this 3 phase mentioned a lot in Thai electric circles but I dont know why? its almost unheard of in the UK for DOMESTIC properties. Lighting, power, shower and even electric storage heaters have their own circuits without 3 phase. However there is a 100 amp supply coming in to many houses. I dont know what you get in Thailand? Any electrician explain?

[junkofdavid2]

a cheap extension even though mark high maybe not,if i use my deep fat fryer and shower at the same time it trips,3 phase is whats needed,an electrian just said put a bigger fuse in the box ,go figure

I heard this 3 phase mentioned a lot in Thai electric circles but I dont know why? its almost unheard of in the UK for DOMESTIC properties. Lighting, power, shower and even electric storage heaters have their own circuits without 3 phase. However there is a 100 amp supply coming in to many houses. I dont know what you get in Thailand? Any electrician explain?

I'm also a little bit confused about it.

Anyway, here's the Wiki

http://en.wikipedia.org/wiki/Three-phase_power

[Cuban]

1) Can moisture or fault in the appliance cause the circuit breaker to trip?

If yes, how so?

If the CB in question is a simple 'break on over current' device, moisture, burnt food or a fault could cause a short circuit drawing more than the CB's rated current resulting in the device tripping. Even a large bug trying to escape the sudden heat might pop your CB as the electrical arc sprays bug over the inside of the cooker.

2) Can a cheap extension cord also cause a circuit breaker to trip?

If yes how so?

Nice long extension leads that are not Fully unwound when in use heat up, this can reach a point where the insulation melts and again a short circuit can occur tripping the CB or starting a fire if you are less lucky.

Assuming your cooker is made partly of metal and assuming your extention coil/drum is only two core cable (as most in Thailand are) - I would question if this is really a wise thing to do?

This simple thread sums up the problems with domestic electrical installations in Thailand, earthing, fusing, outlets and extension cables.

[lopburi3]

On thing not mentioned - and is a safety issue: you have a unit designed to be grounded (3x1mm proves that) and are not doing so. You need to use make sure the unit has a ground - either with the electric line or from the metal chassis. This is to protect you. I suspect it has a two pin plug but with metal strips on the side that are designed to be the ground. If your outlets have three pins (grounded) you need to buy an adapter to mate that to your plug (available in HomePro). Do not use an extension cord unless 3 wire/grounded and of sufficient capacity. If you need to install a new cord to the unit be sure they install the proper 3 wire/plug.

As mentioned many things could have caused the momentary short (lizard - liquid) but unit should be checked/exchanged. I would be very careful not to touch any metal part of it.

[junkofdavid2]

1) Can moisture or fault in the appliance cause the circuit breaker to trip?

If yes, how so?

If the CB in question is a simple 'break on over current' device, moisture, burnt food or a fault could cause a short circuit drawing more than the CB's rated current resulting in the device tripping. Even a large bug trying to escape the sudden heat might pop your CB as the electrical arc sprays bug over the inside of the cooker.

2) Can a cheap extension cord also cause a circuit breaker to trip?

If yes how so?

Nice long extension leads that are not Fully unwound when in use heat up, this can reach a point where the insulation melts and again a short circuit can occur tripping the CB or starting a fire if you are less lucky.

Assuming your cooker is made partly of metal and assuming your extention coil/drum is only two core cable (as most in Thailand are) - I would question if this is really a wise thing to do?

This simple thread sums up the problems with domestic electrical installations in Thailand, earthing, fusing, outlets and extension cables.

Hmmm... How long is long for an extension coil not fully unwound? Is 1m of unwound coil out of a 5m cord big?

(I have another thicker 5m ext. cord 2x1 with fuse and I was thinking of replacing with that, but haven't done so because of opinions here.)

[junkofdavid2]

On thing not mentioned - and is a safety issue: you have a unit designed to be grounded (3x1mm proves that) and are not doing so. You need to use make sure the unit has a ground - either with the electric line or from the metal chassis. This is to protect you. I suspect it has a two pin plug but with metal strips on the side that are designed to be the ground. If your outlets have three pins (grounded) you need to buy an adapter to mate that to your plug (available in HomePro). Do not use an extension cord unless 3 wire/grounded and of sufficient capacity. If you need to install a new cord to the unit be sure they install the proper 3 wire/plug.

As mentioned many things could have caused the momentary short (lizard - liquid) but unit should be checked/exchanged. I would be very careful not to touch any metal part of it.

1) The unit has a 2 pin plug (round, not flat) and in the place for the ground, there's some kind of metal hole. What do I do with that?

2) How do I know if an extension cord is 3wire/grounded? And how do you know if it's sufficient capacity?

3) Where to buy such 3wire/grounded extension cord with sufficient capacity? Would the usual places like Tesco Lotus have it?

4) By the way, the wall outlet seems to have a ground socket... which I could make use of with the proper cord or even a proper extension cord?

Edited April 14, 2008 by junkofdavid2

[Tywais]

Hmmm... How long is long for an extension coil not fully unwound? Is 1m of unwound coil out of a 5m cord big?

My engineering 2 cents on this issue. Just a possibility though. If there is any inductance in the AC cord/stove then when the control is turned to lower it will open contacts. An inductor will tend to try and maintain the current and when the switch opens the voltage across the switch will go up as the inductor's field collapses. Therefore, a spark near the knob. The back emf (inductor voltage due to collapsing field) can be high enough to arc across the insulation in a low quality cable/extension causing a temporary short tripping the breaker.

A extension coil that is wound in a coil will behave as an inductor and exhibit the above conditions. So a straight, unwound extension of just the correct length and size would eliminate this.

Again, this is an engineering viewpoint based on the information given and may or may not be the situation.

[lopburi3]

1. That plug is designed for export to Europe and does not work in Thai outlets without an adapter. The only place I have seen the adapter is HomePro stores in the packaged electrical items. It is a white plastic slip on that allows the two round pins through it and adds the additional ground pin and mates with the ground on side of plug. If you can't find have a shop install a three pin plug.

2. Check the plug - if three pin and outlets are three pin it is most likely grounded - they often sell three pin outlets with a two pin plug and you know that is not grounded. Check the rating.

3. Lotus would be my last choice (have not seen for ages). Best place are computer stores as they require the grounded outlets and sell good quality cords. HomePro or electrical supply houses should also have. Look for heavy round cord and not too long. It is really best to try and locate units closer to outlet rather than use extension cords.

4. Hopefully the outlet is really grounded - newer places should be but I would always check with a multi-meter to be sure (same voltage from hot to neutral and ground). But that is best done by an electrician with you just watching.

[JAS21]

1. That plug is designed for export to Europe and does not work in Thai outlets without an adapter. The only place I have seen the adapter is HomePro stores in the packaged electrical items. It is a white plastic slip on that allows the two round pins through it and adds the additional ground pin and mates with the ground on side of plug. If you can't find have a shop install a three pin plug.

2. Check the plug - if three pin and outlets are three pin it is most likely grounded - they often sell three pin outlets with a two pin plug and you know that is not grounded. Check the rating.

3. Lotus would be my last choice (have not seen for ages). Best place are computer stores as they require the grounded outlets and sell good quality cords. HomePro or electrical supply houses should also have. Look for heavy round cord and not too long. It is really best to try and locate units closer to outlet rather than use extension cords.

4. Hopefully the outlet is really grounded - newer places should be but I would always check with a multi-meter to be sure (same voltage from hot to neutral and ground). But that is best done by an electrician with you just watching.

Lop

I went to buy one of these 'ovens' in the local Mall, this one was 2400watts I recall. Was amazed that the plug was only two pin, yet the oven casein was metal.

So am looking for a three pin plug before purchase..thanks for the info.

So many prople just dont realise the importance of an earth. My house does have SAFE-T-CUT.

[Cuban]

1) The unit has a 2 pin plug (round, not flat) and in the place for the ground, there's some kind of metal hole. What do I do with that?

This would be a French designed plug, see this link, designed for the European French/German market. The 'extra' metal hole on the free plug is the place for the earth pin that you will find on French wall sockets. But you will need a very long lead to use your cooker in Thailand.

I think this has been discused on TV in the past. I have seen the correct French style wall mounted sockets to work with these plugs in Thailand - but they were personal imports from Europe. The plug you have will have a small nick in the edge where there is also a piece of metal - this is to allow the plug to function both in France and Germany where the plug/socket type is called Schuko, see this image.

The Thai style connector allows for both European style two pin round, and the American two pin flat plugs to be used. I have seen some that also accept the English three pin square. But as many houses do not have a real earth the whole subect is a bit academic.

Maybe better to switch to gas or charcoal?

A extension coil that is wound in a coil will behave as an inductor and exhibit the above conditions. So a straight, unwound extension of just the correct length and size would eliminate this.

When wound in a coil the safe current carrying capacity of a cable is lower than the figure stamped along the cable's length, part of the reason that a cable can pass X Amps safely is that the cable is unwound and is able to dissipate some of the heat that passing the current generates.

Extension cables - use with the cable unwound from the drum or better still do not use at all.

For high current devices like cookers - do not use extension cables of any type - you are likely to stress the cable by using it out of it's designed purpose (for TV or HiFi - fine). Also it is unlikely the extension cable provides an earth - and if it does as you are providing an earth via two sets of plug/socket connections it will not be a very good earth when you finally present the 'earth" to the cooker.

Pizza Home delivery = 1112.

[junkofdavid2]

You guys all make sense, and thanks for that.

However, now the big question is... Do a vast majority of Thai households really do all these safety measures suggested here?

(Don't use extension cords, use a ground plug even if the appliance doesn't come with a usable one, etc.)

1) If the answer is no, how do they survive?

2) I live in an apartment building with about 40 individual apartments. If I follow all this safety advise, is totally useless if the rest of my neighbors don't do it?

[lopburi3]

1. Some do - some don't - but ELB type (Safe-T-Cut) type protection is often used here so that may help keep the death rate down.

2. It is you that will lose your life in the event of electrocution and it is for you that you observe some cautions.

Most outlets in modern homes in Thailand have American/Japanese type three pin outlets that will accept either round or flat pins for hot/neutral.

[longball53098]

1. That plug is designed for export to Europe and does not work in Thai outlets without an adapter. The only place I have seen the adapter is HomePro stores in the packaged electrical items. It is a white plastic slip on that allows the two round pins through it and adds the additional ground pin and mates with the ground on side of plug. If you can't find have a shop install a three pin plug.

2. Check the plug - if three pin and outlets are three pin it is most likely grounded - they often sell three pin outlets with a two pin plug and you know that is not grounded. Check the rating.

3. Lotus would be my last choice (have not seen for ages). Best place are computer stores as they require the grounded outlets and sell good quality cords. HomePro or electrical supply houses should also have. Look for heavy round cord and not too long. It is really best to try and locate units closer to outlet rather than use extension cords.

4. Hopefully the outlet is really grounded - newer places should be but I would always check with a multi-meter to be sure (same voltage from hot to neutral and ground). But that is best done by an electrician with you just watching.

Heres a photo of the Schuko plug and adapter,,,,,,,,,,,maybe it will help the poster

[junkofdavid2]

1. That plug is designed for export to Europe and does not work in Thai outlets without an adapter. The only place I have seen the adapter is HomePro stores in the packaged electrical items. It is a white plastic slip on that allows the two round pins through it and adds the additional ground pin and mates with the ground on side of plug. If you can't find have a shop install a three pin plug.

2. Check the plug - if three pin and outlets are three pin it is most likely grounded - they often sell three pin outlets with a two pin plug and you know that is not grounded. Check the rating.

3. Lotus would be my last choice (have not seen for ages). Best place are computer stores as they require the grounded outlets and sell good quality cords. HomePro or electrical supply houses should also have. Look for heavy round cord and not too long. It is really best to try and locate units closer to outlet rather than use extension cords.

4. Hopefully the outlet is really grounded - newer places should be but I would always check with a multi-meter to be sure (same voltage from hot to neutral and ground). But that is best done by an electrician with you just watching.

Heres a photo of the Schuko plug and adapter,,,,,,,,,,,maybe it will help the poster

Thanks! Will look for that!

So now, on my HomePro list:

1) Schuko Adapter

2) Longer appliance cord similar to the one which comes with the appliance (actually detachable), of similar or greater thickness of 3X1 sq.mm. If this new cord already has a 3 pin, then no more need to buy the Schuko adapter mentioned above.

3) Anything else I might need for added safety?

One 'good' thing about the dangerous extension cord is that it has it's own 10-15A fuse which acts as a mini circuit breaker and first defense. If I simply replace the cord to a longer one, I will lose this advantage. Anything I can do to still have a mini circuit breaker despite losing the extension cord?

[lopburi3]

If you can install an ELB, RCD, GFI (Safe-T-Cut type unit) it is a very good investment (even if you have to pay for it). It shuts off the electric supply fast enough to save your life in most circumstances. So having grounds and the ELB is a very wise move.

[junkofdavid2]

If you can install an ELB (Safe-T-Cut type unit) it is a very good investment (even if you have to pay for it). It shuts off the electric supply fast enough to save your life in most circumstances. So having grounds and the ELB is a very wise move.

What does it look like?

[lopburi3]

A large circuit breaker. If you go to HomePro there will be a wall of them for sale. You may already have - ask your landlord. If not he might buy or pay part. They are in very common use here (they also work when there is no ground as is often the case).

[junkofdavid2]

A large circuit breaker. If you go to HomePro there will be a wall of them for sale. You may already have - ask your landlord. If not he might buy or pay part. They are in very common use here (they also work when there is no ground as is often the case).

Oh, I already have one of those inside my room I think... each apartment room has it. It's about 7 inches tall and 10 inches wide, with about 2 + 4 rows of black switches on it... and connected to this sorta main switch.

That's the one which tripped and had to simply reset one of the 6 switches on it.

I studied it closely just now and indeed, the main switch says EARTH LEAKAGE CIRCUIT BREAKER.

Is that the one?

If indeed it is the one, is one enough for my apartment room or do I need one specially for the cooking stove?

Edited April 14, 2008 by junkofdavid2

[Rimmer]

The purpose of an MCB or an HRC fuse or even a rewirable fuse in the distribution board is to protect the cables. That is all. Even electrical engineers often loose site of this little known fact.

An MCB does not and is not intended to protect life.

An MCB gives what is called close protection, it is better than an HRC fuse which has different tripping characteristics

and discrimination under fault conditions.

If an MCB trips suddenly as the OP describes then there could be a L to N fault. If there was a problem with the cable extension reel or plug pins heating this is a different tripping mechanism within the MCB and will often take many hours to trip under such overload conditions.

If your appliance tripped out the breaker within a few minutes of turning it on best to get it checked out. Modern MCBs do not trip quickly for no reason at all.

[lopburi3]

I studied it closely just now and indeed, the main switch says EARTH LEAKAGE CIRCUIT BREAKER.

Yes that is the ELB/RCD/GFI.

[junkofdavid2]

If an MCB trips suddenly as the OP describes then there could be a L to N fault. If there was a problem with the cable extension reel or plug pins heating this is a different tripping mechanism within the MCB and will often take many hours to trip under such overload conditions.

If your appliance tripped out the breaker within a few minutes of turning it on best to get it checked out. Modern MCBs do not trip quickly for no reason at all.

Circuit breaker tripped after stove was "on" for some time, maybe about 40 min... but it happened as I was turning the knob DOWN to a lower heat level...

Very strange...

Edited April 14, 2008 by junkofdavid2