News Forum - Bangkok man electrocuted to death charging his phone

[Thaiger]

A young Thai man was found dead in his room in Bangkok this morning clutching a phone on charge. Police say he was electrocuted to death. At 8am, officers at Rat Burana Police Station were informed of a death in a rented room in Bang Mod subdistrict, Thung Khru district. Police, doctors from Bangkok’s Siriraj Hospital, …

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[Soidog]

Tragic but not unusual. We all see the scant regard for health and safety with many aspects of Thai life. Everything from dodgy electrics to large buses stopped in traffic with the back engine cowling open exposing moving machinery to 30 kids hanging off the back of a Songthaew after school. No education on the topic and an attitude of Mai Pen Rai. Not going to change anytime soon. 
 

On this particular case, will the authorities be checking to see if the room this young guy rents is fitted with an RCD? I’m not sure if rented properties require electrical protection devices? If they do or do not then that’s another follow up action that won’t be pursued. 

[palooka]

As most RCDs are made in China, also check that the one you bought at THAT "reputable Thai shop" actually works.  I check mine about once a month. 

TIT.  Smoke alarms I check monthly, hard wired not so much as they are passed through the RCD.

Because of toddlers now visiting the house I have had all power points (all Live in Thailand), put them through a power switch that is out of their reach. Costs but children are precious.

Son in law does the electrics and gets a bit pissed that I am looking over his shoulder all the time, BUT he is Thai trained, which means he has no formal qualifications etc etc, just like the builder most get in Thailand to build their homes.

[JJJ]

I don’t understand the chain here.

First of all how do you get from a plug missing metal parts to wires inserted directly into a socket?  In order to replace a plug with wires to be directly inserted don’t you need to cut the whole plug off and splice the wires?

Also even if that whole part was messed up how do you get from extension cord through the charging cord and the phone and then the phone to the hands. Even without an Rcd, why didn’t a main circuit break before he even picked up the phone? 

If this was an electrocution, then something else allowed main voltage to continue uninterrupted (and a lot) to electrocute presumably dry skin, through a case and glass.  

[Pinga]

43 minutes ago, JJJ said:

 In order to replace a plug with wires to be directly inserted don’t you need to cut the whole plug off and splice the wires?

Probably what he actually did - which is nuts - especially considering you can buy a new extension cord for like 50 baht instead of using a dodgy broken one. But yes- it is a mystery to me how holding a phone can actually electrocute someone - the USB cables aren't designed to deliver high voltages.

[JJJ]

23 minutes ago, Pinga said:

Probably what he actually did - which is nuts - especially considering you can buy a new extension cord for like 50 baht instead of using a dodgy broken one. But yes- it is a mystery to me how holding a phone can actually electrocute someone - the USB cables aren't designed to deliver high voltages.

My only point about the plug is the article says “it was missing metal parts”. I don’t think thats possible. You should have to cut the plug portion back to the wires. I wouldn’t describe cutting back the wire and directly inserting it as missing metal parts. maybe he did that but it’s incorrectly described by either the police or the author. 

But even then that just implies there is a cross at source of the plug—the exposed wires are touching.

But if there’s a direct cross of wires how is a main breaker not tripped? And even then, how does it go through the rest of the first cord through a second plug up a phone charger and through a phone at a lethal level. 

Put another way, even if the plug is removed and the wires are directly inserted, would that electrocute someone?  

Anyway I don’t doubt he was electrocuted but it seems like he’s been quickly blamed for his own death. As usual in Thailand start by blaming the victim  

 

 

[Soidog]

I’m assuming the answer to some of the above statements is as follows:

The original plug consisted of mental pins with a hole and screw to attach the Live, Neutral and possibly Earth (ground) to the respective pins. The pins,  for whatever reason were now missing and so he simply inserted the Live and Neutral in to the mains socket. I don’t believe this played a role in the incident. The fault, whatever it was, must have been within the charger and placed mains voltage on the 0Volt output of the charger. This could be due to a fault on the input transformer within the charger. This mains voltage on the 0 volt line of the charging cable,  which in turn is connected to the body or metal parts of the phone. When the guy held the phone, or was gripping it at the time of the fault, he would have completed the circuit and current would have passed to Earth (Ground) through him. An RCD would have protected him but a circuit breaker not necessarily so. It depends how much current was flowing through him. Most breakers for mains sockets are rated at 16Amps to 20Amps. A current as low as 0.1-0.2 Amps is enough to kill you. It’s current that kills, not voltage. In addition, circuit breakers aren’t always quick enough to isolate the circuit to stop personal injury or death, while RCD’s are. 
 

Quality chargers have other safety features built in, such a fuses rated at a few milliamperes which would have blown in such a situation. Cheap chargers often don’t have such a feature. These quality chargers also use “Opto Isolators or Opto-Couplers between the primary and secondary side of the circuit. Then there are aspects of double insulation or reinforced insulation. 
 

Morale of this story? Don’t buy a cheap charger from Lazada. Pay for a quality charger. In the long run it will last more years and perhaps save your life or that of your family. 

[engineer21]

Cheap USB chargers can kill: https://wonderfulengineering.com/cheap-chinese-phone-charger-electrocutes-woman-to-death/

Condolences to his family and friends.

[engineer21]

I belatedly read Soidog's comment above -- wholehertedly concur with his reasoning and conclusion. Words for the wise.

[Leo]

9 hours ago, Soidog said:

I’m assuming the answer to some of the above statements is as follows:

The original plug consisted of mental pins with a hole and screw to attach the Live, Neutral and possibly Earth (ground) to the respective pins. The pins,  for whatever reason were now missing and so he simply inserted the Live and Neutral in to the mains socket. I don’t believe this played a role in the incident. The fault, whatever it was, must have been within the charger and placed mains voltage on the 0Volt output of the charger. This could be due to a fault on the input transformer within the charger. This mains voltage on the 0 volt line of the charging cable,  which in turn is connected to the body or metal parts of the phone. When the guy held the phone, or was gripping it at the time of the fault, he would have completed the circuit and current would have passed to Earth (Ground) through him. An RCD would have protected him but a circuit breaker not necessarily so. It depends how much current was flowing through him. Most breakers for mains sockets are rated at 16Amps to 20Amps. A current as low as 0.1-0.2 Amps is enough to kill you. It’s current that kills, not voltage. In addition, circuit breakers aren’t always quick enough to isolate the circuit to stop personal injury or death, while RCD’s are. 
 

Quality chargers have other safety features built in, such a fuses rated at a few milliamperes which would have blown in such a situation. Cheap chargers often don’t have such a feature. These quality chargers also use “Opto Isolators or Opto-Couplers between the primary and secondary side of the circuit. Then there are aspects of double insulation or reinforced insulation. 
 

Morale of this story? Don’t buy a cheap charger from Lazada. Pay for a quality charger. In the long run it will last more years and perhaps save your life or that of your family. 

The article states (rather clearly I thought) that it was the extension cord that was "doctored", not the charger and cable that people talk about here. Can you please simplify what happened here then, and what the advice is for buying extension cords?

Edited February 9, 2023 by Leo

[Bluesofa]

8 hours ago, Soidog said:

The pins,  for whatever reason were now missing and so he simply inserted the Live and Neutral in to the mains socket. I don’t believe this played a role in the incident. The fault, whatever it was, must have been within the charger and placed mains voltage on the 0Volt output of the charger. This could be due to a fault on the input transformer within the charger. This mains voltage on the 0 volt line of the charging cable

Regarding a transformer in the charger. I've read that some very cheap nasty chargers use a capacitive dropper to reduce the voltage, rather than a transformer.

I haven't found a link so far that specifically states this, but here's a wiki link of how it works: https://en.wikipedia.org/wiki/Capacitive_power_supply   Despite R1 and R2 providing a physical connection between the incoming mains and the output to the phone, if C1 fails and goes short-circuit, then there's a lot higher voltage going to the phone.

There are also a couple of links to cheap chargers using a transformer, showing how these are dangerous:
https://poweren.com/safety/can-a-mobile-phone-charger-be-dangerous/
http://www.righto.com/2012/03/inside-cheap-phone-charger-and-why-you.html

 

 

[JJJ]

9 hours ago, Soidog said:

I’m assuming the answer to some of the above statements is as follows:

The original plug consisted of mental pins with a hole and screw to attach the Live, Neutral and possibly Earth (ground) to the respective pins. The pins,  for whatever reason were now missing and so he simply inserted the Live and Neutral in to the mains socket. I don’t believe this played a role in the incident. The fault, whatever it was, must have been within the charger and placed mains voltage on the 0Volt output of the charger. This could be due to a fault on the input transformer within the charger. This mains voltage on the 0 volt line of the charging cable,  which in turn is connected to the body or metal parts of the phone. When the guy held the phone, or was gripping it at the time of the fault, he would have completed the circuit and current would have passed to Earth (Ground) through him. An RCD would have protected him but a circuit breaker not necessarily so. It depends how much current was flowing through him. Most breakers for mains sockets are rated at 16Amps to 20Amps. A current as low as 0.1-0.2 Amps is enough to kill you. It’s current that kills, not voltage. In addition, circuit breakers aren’t always quick enough to isolate the circuit to stop personal injury or death, while RCD’s are. 
 

Quality chargers have other safety features built in, such a fuses rated at a few milliamperes which would have blown in such a situation. Cheap chargers often don’t have such a feature. These quality chargers also use “Opto Isolators or Opto-Couplers between the primary and secondary side of the circuit. Then there are aspects of double insulation or reinforced insulation. 
 

Morale of this story? Don’t buy a cheap charger from Lazada. Pay for a quality charger. In the long run it will last more years and perhaps save your life or that of your family. 

Obviously we can only apply logic to the few details that are provided— but this makes a lot more sense then the official explanation.

Also I guess the extension cord also didn’t have a fuse either? 

As I noted before whenever the RTP and media blame the victim you can almost be sure someone else is actually at fault—here both the manufacturer and of course the “system” that allows cheap untested devices in. 

I have imported electric devices for sale before through the proper channels and it’s time consuming and expensive. You can be sure the 50 baht chargers didn’t come in the same way. 

[HolyCowCm]

Thai welders are always putting bare wires into plug outlets so him doing this doesn't suprise me of the mentaility.

[Soidog]

6 hours ago, Leo said:

The article states (rather clearly I thought) that it was the extension cord that was "doctored", not the charger and cable that people talk about here. Can you please simplify what happened here then, and what the advice is for buying extension cords?

The “doctored” comment refers to something that has been changed or modified from its original state to make it work. In this instance it seems the pins of the plug had perhaps been damaged, so rather than buy a new extension cable, he simply took the wires out of the plug and placed them directly in the socket on the wall.
 

Without being there it’s not possible to be 100% sure, but its not easy to see why doing that would make the phone Live, as the connection to it was passing through the charger. This then indicates to me, that it was the charger that subsequently went faulty and the so called “doctored” cable was just a coincidence. 
 

The main advice for buying an extension cable would be to normally look for a specific “standards marking” such as CE for goods used in Europe. However, these are easily faked and so my main advice is more about Power Rating.  I see people buying these cheap 100 baht cables from BigC and then plugging a kettle, hair dryer or washing machine in to it. It’s all about the Power rating, but in particular the Current rating. (Power = Voltage X Current). These cheap extension leads should only be used for small low power appliances. If you are going to be using power tools, or plugging a kettle in to it then make sure it’s at least 20 amp (current) rated.
 

The other advice with an extension cable is to buy one that has a safety cut out built in, Ideally an RCD. Although this will make it more expensive, this will protect you if the cable gets damaged such as cutting it by mistake or the appliance you are using develops a fault; as perhaps in this incident.  I would also say that it is essential to have an RCD if used outside. After that, making sure you don’t damage it and keep it in a good condition and it should be fine fine for years. 

[Soidog]

6 hours ago, Bluesofa said:

Regarding a transformer in the charger. I've read that some very cheap nasty chargers use a capacitive dropper to reduce the voltage, rather than a transformer.

I haven't found a link so far that specifically states this, but here's a wiki link of how it works: https://en.wikipedia.org/wiki/Capacitive_power_supply   Despite R1 and R2 providing a physical connection between the incoming mains and the output to the phone, if C1 fails and goes short-circuit, then there's a lot higher voltage going to the phone.

There are also a couple of links to cheap chargers using a transformer, showing how these are dangerous:
https://poweren.com/safety/can-a-mobile-phone-charger-be-dangerous/
http://www.righto.com/2012/03/inside-cheap-phone-charger-and-why-you.html

Yes, this type of supply is very dangerous other than in fixed installations such as security lighting using LED’s. It’s possible there are chargers on the market with this arrangement which of course makes them highly dangerous. As you say, single component failures can place mains voltage on the output. Many phone chargers use a simple rectifier followed by a high frequency oscillator and then a transformer. This keeps the size and cost of the transformer much lower than a transformer placed on the input of the charger. I would never wish to use a capacitive dropper on anything I was going to touch on a regular basis. 

I guess it’s like all things in life. Generally the more you pay the better they are. If it’s life threatening then you should be buying a quality make and quality brand. This of course presents its own problems in Thailand as an “Apple” product doesn’t mean it’s a genuine Apple product!