Acer E5-575 laptop current flow design

slnacer

Recently I noticed tingling+uncomfortable shocks in touching most areas of keyboard in E5-575 laptop.
Local Acer service centre guys when contacted replaced laptop adaptor/charger as it was not charging battery inside saying it was faulty , moreover advised to use a grounded/earthed connection in case I am not using already.
I use grounded wall socket only .
Here I would like to know why current leaked onto keyboard when charger/adapted fails.
Is the safety design to remove stray/leaked currents away from end user not at all in design or that didn't work which is even more risky?

Can someone knowledgeable throw light on earth/ground wiring design,metal casing wiring on laptop etc in E5-575 models?

JackE

The charger's function is to provide mains isolation, not the laptop's. Jack E/NJ 

slnacer

Thanks for your reply.
But don't you think the laptop build should have sufficient insulation to protect end user from such critical faults in accessories say a connected charger/adapted.
I have used dell laptops for last 10+ yrs never I have experienced shocks upto keyboard or near touch pad. I used to get mild pricks near some ports in sides at the max.
Acer e series laptops build not upto mark imho

JackE

No. No laptops, indeed no portable rechargeable devices of any kind, are built to protect the user when a charger fails in such a way that mains isolation is lost and mains voltage reaches the charger's plug. This is why ground fault mains circuit interrupters are recommended even for double insulated devices. Jack E/NJ

slnacer

Hmm.little hard to believe though.
But still I wonder despite of no earthing issues with my wall outlet(verified with a qualifiedelectrician...)I thought current should have gone through ground wire before it reached laptop...didn't happen.

Thanks anyway for reply

JackE

Doesn't matter if there are no issues with the mains or the mains receptacles. You simply don't have a ground fault circuit interrupter (GFCI) installed on the mains receptacle that you're using. I have GFCIs installed in my bathroom and my workbench receptacles because if a device like a shaver or electric drill fails, I could get electrocuted due to nearby ground points (plumbing).That's what a GFCI receptacle or breaker does. It monitors the current from the hot mains wire into the charger (or any device plugged into the mains) and also monitors the current out of the charger or device to the mains neutral wire. If the current in, is more than the current out, then there's a leak to ground in the charger or device. The GFCI detects this inequality and will shut the mains off. Jack E/NJ

slnacer

I understand the purpose of GFCI to detect what you said leak. But excuse me for my ignorance still if any here that:
Is it not the purpose of earthing(as it is called in my region) or ground wire to send away such stray or leaked current thereby prevent end user getting exposed to that current reaching ground through him or her.? In my case was there a break somewhere in ground wire or is it not working as efficient as it should be?
 Ground fault interrupter I will consider.
Thanks

JackE

Yes. But the mains ground wire only protects the circuit from an electrical fire via a convential circuit breaker or fuse --- it doesn't protect you.. The mains ground and fuse can carry far more lethal amperes than a GFCI will allow. Remember, the amperes in from the hotwire must equal amperes out thru the neutral wire for the GFCI to remain on. So if there's a small sub-milliampere level difference between the two (probably enough for you to feel a tingle since you were not grounded that well) the GFCI will shut off --- it happens so fast that you might not even have felt the tingle. Without the GFCI, the tingle would continue until you touched a good ground and then, well, you might get zapped. If you want near 100% safety from any plug-in device, install a GFCI receptacle on your mains outlet or a GFCI circuit breaker instead of a usual mains circuit breaker. Jack E/NJ

PS: I learned my lesson a long time ago with a double-insulated drill that had a wire fray inside touched a metal mounting nut on the drill that my hand touched. I couldn't let go on the damp cellar floor. Luckily my sister heard me screaming and rushed down to pull the plug. From then on only GFCI receptacles on my cellar workbench. Jack E/NJ