Family of three electrocuted to death at Taman Jurong

[BanCoe]

@Ender 

3 minutes ago, Ender said:

Ya, most light switches, and even the common power socket are single pole.  Means neutral is not cut.

Huh?? i blurr ....... i thought common power socket got neutral ( I see got so many coloured wires inside mah) Got green , blue and brown I remember inside   

[Ender]

2 minutes ago, BanCoe said:

@Ender 

Huh?? i blurr ....... i thought common power socket got neutral ( I see got so many coloured wires inside mah) Got green , blue and brown I remember inside   

IS it? haven't change power socket before. Did changed light switches though, which confirm only connect LIVE to the switch..  

[Kb27]

1 hour ago, BanCoe said:

@Ender 

Huh?? i blurr ....... i thought common power socket got neutral ( I see got so many coloured wires inside mah) Got green , blue and brown I remember inside   

My hdb flat original wiring to the power socket is for "single pole" switching. All the power socket only switch the "live" wire. They do not switch the neutral.

All the neutral wires are just wired from one socket to the next socket and so on. No breaks. They all joined back in continuous wires to the circuit breaker on a "bar". Same as for earth wire.

The MCB (individual breakers, in the breaker box) only connect to the "live" wire. So they break the live wire only, but don't break neutral wire.

Wire colour depend on older or newer specs.

https://www.ema.gov.sg/cmsmedia/Handbook/Poster_Cable_Colour_Code_Change.pdf

Residential power is single phase.

 

And if you have a US-powered appliance, it is a different set of wire colors. Their neutral is white, live is black, whereas our black (old colour code) is neutral.

Confusing ? Just don't touch the wrong wire. 

Edited March 10, 2022 by Kb27

[Volvobrick]

28 minutes ago, Kb27 said:

My hdb flat original wiring to the power socket is for "single pole" switching. All the power socket only switch the "live" wire. They do not switch the neutral.

All the neutral wires are just wired from one socket to the next socket and so on. No breaks. They all joined back in continuous wires to the circuit breaker on a "bar". Same as for earth wire.

The MCB (individual breakers, in the breaker box) only connect to the "live" wire. So they break the live wire only, but don't break neutral wire.

Wire colour depend on older or newer specs.

https://www.ema.gov.sg/cmsmedia/Handbook/Poster_Cable_Colour_Code_Change.pdf

Residential power is single phase.

 

And if you have a US-powered appliance, it is a different set of wire colors. Their neutral is white, live is black, whereas our black (old colour code) is neutral.

Confusing ? Just don't touch the wrong wire. 

Landed residential can have 3-phase supply. That's a bit more complicated.

[13177]

6 hours ago, Adrianli said:

They are not not safe. They were built in the 1970's so if you still operate 19870's appliances or do not use much electrical appliances, you are still safe. If you been to those elderly HDB flat which are sparsely furnished and they just have a small fan, fridge and tv. They wouldn't have any electrical problems.

But if you are going for modern day aircon, water heater, induction cooker, oven, bitcoin mining rig, big screen tv, washing machine, etc.... Then those electrical breakers will not be able to handle the load.

 

So if buy those 70s flat as resale, must redo whole house electrical wiring. Then for those who is the first owner of the flat, must move house liao. Lol.

[Lala81]

Is there some youtube video that explains electrical circuits?

 

[Volvobrick]

12 minutes ago, Lala81 said:

Is there some youtube video that explains electrical circuits?

 

This channel quite good. 

 

 

[Ender]

 

 

3 hours ago, Volvobrick said:

This channel quite good. 

 

 

Subcribe now.. Never dare to touch circuit breaker.

Edited March 10, 2022 by Ender

[Kb27]

4 hours ago, Lala81 said:

Is there some youtube video that explains electrical circuits?

 

 

[Somewhat1975]

For the old flat, three things can be done on the water heater to prevent electrocution

1) Buy water heater with build-in ELB or RCCB

like this one. 

2) don't change the plastic hose comes with the heater to a nice looking metallic hose. Electricity is mostly likely conducted via metallic hose and not through the water.

3) check the power cable connected to the heater. Some contractors are just ignorant. They might use 40/0076 cable, which can only support 10A of current. 70/0076 cable can support 15A. I am kiasi. So I change the cable installed by my contractor to 110/0076 cable or 2.5mm2 cable, which can support up to 20A.

 

  

 

[Ender]

40 minutes ago, Somewhat1975 said:

For the old flat, three things can be done on the water heater to prevent electrocution

1) Buy water heater with build-in ELB or RCCB

like this one. 

2) don't change the plastic hose comes with the heater to a nice looking metallic hose. Electricity is mostly likely conducted via metallic hose and not through the water.

3) check the power cable connected to the heater. Some contractors are just ignorant. They might use 40/0076 cable, which can only support 10A of current. 70/0076 cable can support 15A. I am kiasi. So I change the cable installed by my contractor to 110/0076 cable or 2.5mm2 cable, which can support up to 20A.

 

  

 

Yes, many thought it's the charged water that kills them. Most of the time it's the metal hose and is connected to the tank and ground..

[Camrysfa]

scary, am an instant water heater user....

just went to see the heater. We have those hoses that's metallic ( or looks like metallic ).

However, the inlet and outlet of the heater is all plastic. So, even if the heater is shorted, electricity cannot flow to the external hoses.

 

[Sosaria]

11 hours ago, Ender said:

Means you flip the switch, both live and neutral get cut off and vice versa..  Single pole switch usually cut off or turn on at the Live wire only.

Learned the hard way last time why it is not enough to switch off (cut off Live connection only) when installing new lights in a room

Turns out some of these circuits are wired in a ring so i still got zapped by the Neutral wire. 

Lesson learned is that always need to switch off one of the CB that controls the lights. Typically for HDB flat, the lights go to either one of two 10A CBs.

[Ender]

16 minutes ago, Sosaria said:

Learned the hard way last time why it is not enough to switch off (cut off Live connection only) when installing new lights in a room

Turns out some of these circuits are wired in a ring so i still got zapped by the Neutral wire. 

Lesson learned is that always need to switch off one of the CB that controls the lights. Typically for HDB flat, the lights go to either one of two 10A CBs.

Good to invest in a mutlimeter with NCV function.  If you are unsure if your working location is still LIVE after swtiching off the swtich, can just bring your NCV multimeter near to wires. It will flash and beep if LIVE wire is detected.

[Sosaria]

9 hours ago, Volvobrick said:

This channel quite good. 

 

 

Good stuff. If can have hands-on installing this distribution box, will have good understanding of the electrical supply routing from external to the various consumer loads in the home. And the various safety devices.

This kind of thing, university graduate in EE also not very sure

 

Edited March 10, 2022 by Sosaria

[Volvobrick]

3 hours ago, Camrysfa said:

scary, am an instant water heater user....

just went to see the heater. We have those hoses that's metallic ( or looks like metallic ).

However, the inlet and outlet of the heater is all plastic. So, even if the heater is shorted, electricity cannot flow to the external hoses.

 

Water is conductive. Inside the plastic is water hor! 

[Kb27]

From hwz, Mistral water heater, seems like a rubber hose leak and spray water all over, internally.

 

[Lala81]

17 hours ago, Volvobrick said:

This channel quite good. 

 

 

To me as a layman. Kb27's video is clearer to understand. More theory based.