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How can I avoid my MacBook Pro giving me minor shocks?

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Re: How can I avoid my MacBook Pro giving me minor shocks?

#91

Post by nraynaud »

Hydraulix989 wrote: post #72
algesten wrote: post #8

I have this problem in India. I suspected the mains was dodgy, because during the many power outages i never got the shocks when on UPS. I got a multimeter and measured. The neutral was 70V and the phase 300ish. So the difference was roughly 230V but a switched power adapter would make this hover around 70 too (I believe an old coil based would probably been fine). The Indian electrician didn't understand my problem…

Shark used to make an (otherwise excellent) upright consumer vacuum cleaner with a metal strip in the handle. The vacuum's power cable did not have a ground. This vacuum had the most five-star reviews on Amazon, but then a minority of people started complaining and leaving one-star reviews, saying they were getting shocked. The reactions from the fanboy crowd were non-sympathetic ("you're imagining it," "it's just st…

I would separate the issues, vacuum cleaners are famous for electrically charging dust up to quite high voltages.

Re: How can I avoid my MacBook Pro giving me minor shocks?

#92

Post by icantdrive55 »

xenadu02 wrote: post #36
kosma wrote: post #23

Earlier quoted context omitted.

This is potentially deadly advice. A neutral/grounding fault will energize all your home devices with live potential; same with a live/neutral swap (unlikely but possible with Indian wiring standards).

> This is potentially deadly advice. A neutral/grounding fault will energize all your home devices with live potential; same with a live/neutral swap (unlikely but possible with Indian wiring standards). You are wrong. In the US the NEC requires this. If you bother to look inside your breaker panel you will find the neutral and ground wires are literally screwed down to the same bus bar. Any path your body (or the so…

In the USA, where we run 240v/120v to most residential homes the ground and neutral is always connected in the main panel.

If you have a sub-panel feeding the main panel, the neutral and ground are Not bonded.

(I mentioned it because the subpanel is overlooked a lot, and wired wrong, or not to code.)

Re: How can I avoid my MacBook Pro giving me minor shocks?

#94

Post by nitrogen »

hatsunearu wrote: post #59
josefdlange wrote: post #17

Ungrounded adapter + bad mains power = zap! Ungrounded adapter + clean mains power = probably no zap Grounded adapter + bad mains power = probably no zap Grounded adapter + clean mains power = no zap It's not just the adapter and it's not just the mains power; it's when both come together. Electricity follows pretty simple rules when it comes down to it. Always always always ground your A/C connections. Why wouldn't…

"clean" mains power has nothing to do with zapping. Where'd you hear this? I've literally never heard this nonsense before.

I suppose a neutral line with a nonzero voltage could be called "dirty", but not in the traditional noise sense.

Re: How can I avoid my MacBook Pro giving me minor shocks?

#95

Post by stillworks »

sfifs wrote: post #3

Don't use Macs but I'm surprised Apple apparently didn't give an earthed power adapter by default on a metal skin product. This seems like negligence. Now that I think about it, my iPad's the same when charging.

In the U.K. they come with earthed plug.

However I still noticed "buzzing" in the MBP, MBA and even iPad when I would touched them.

Took the MBP in to the store. It didn't buzz there. They gave me a new power supply anyways and recommended I connect the plug directly into the wall socket.

Turned out that the power strip I was using is not grounded even though it has three pin sockets !

When I plug Apple devices directly into the wall socket I don't notice any "buzzing".

So now I don't connect the Apple devices via a power strip.

Re: How can I avoid my MacBook Pro giving me minor shocks?

#96

Post by Too »

Teever wrote: post #88
kalleboo wrote: post #78

Earlier quoted context omitted.

I don't think I've ever seen a three-prong outlet in Japan (maybe only new installations?), but "earth screws" are quite common (any room prepared for an air conditioner will have one at least) http://www.hakusui-trading.co.jp/safety/img/img02.jpg

What? That's crazy looking! Why not just put the third prong in there if it's wired up to handle a screw? What's the point?

Just guessing here but I think it's to allow easy grounding of old appliances and other equipment that might risk contact with electricity but are not grounded by default. Metal frame desk as example.

Re: How can I avoid my MacBook Pro giving me minor shocks?

#97

Post by londons_explore »

This problem is common.

You can solve it by opening up the power supply and ripping out the bright blue Y capacitor inside. It looks like a slim M&M with 2 legs. Both apple official and 3rd party power supplies will have one.

Do not damage the capacitor without removing it - that could lead to an electric shock. You can remove it by cutting it off with pliers or wire cutters.

The power supply will work fine afterwards, but might emit a bit of radio interference, although generally not too much.

Re: How can I avoid my MacBook Pro giving me minor shocks?

#98

Post by londons_explore »

algesten wrote: post #8

I have this problem in India. I suspected the mains was dodgy, because during the many power outages i never got the shocks when on UPS. I got a multimeter and measured. The neutral was 70V and the phase 300ish. So the difference was roughly 230V but a switched power adapter would make this hover around 70 too (I believe an old coil based would probably been fine). The Indian electrician didn't understand my problem…

Neutral can be as high as 400v relative to earth and the power still be within specification. 30 volts is more typical though.

It's the devices responsibility to design for that.

Re: How can I avoid my MacBook Pro giving me minor shocks?

#99

Post by Hydraulix989 »

nraynaud wrote: post #91
Hydraulix989 wrote: post #72

Earlier quoted context omitted.

Shark used to make an (otherwise excellent) upright consumer vacuum cleaner with a metal strip in the handle. The vacuum's power cable did not have a ground. This vacuum had the most five-star reviews on Amazon, but then a minority of people started complaining and leaving one-star reviews, saying they were getting shocked. The reactions from the fanboy crowd were non-sympathetic ("you're imagining it," "it's just st…

I would separate the issues, vacuum cleaners are famous for electrically charging dust up to quite high voltages.

I should clarify that the reports indicated that the shock originated from the hand touching the handle.
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