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Author Topic: How can I have 35v to ground ?  (Read 12629 times)

Steve M Smith

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Re: How can I have 35v to ground ?
« Reply #10 on: September 27, 2014, 04:46:33 AM »

On the old guitar amps, etc., as I recall many had a .1uF, or so, cap from each leg of the line to the chassis

I thought it was just one with a switch to connect it to one or other of the power input lines.  Always looked a bit crazy to me!

EDIT: Like this:



Although this looks even more scary:



That one relies on turning the two pin plug round to get the capacitor on the neutral/ground side.

Steve.
« Last Edit: September 27, 2014, 04:52:16 AM by Steve M Smith »
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Mike Sokol

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Re: How can I have 35v to ground ?
« Reply #11 on: September 27, 2014, 08:20:07 AM »

Yikes! I had no idea about the iPhone charger electrocutions. (And there I was vaccuming away on a wet concrete floor...)

See below:

Hong Kong (CNN) -- U.S. electronics giant Apple is investigating reports in China that a woman died after being electrocuted while trying to make a call with her iPhone 5 while it was charging.

Ma Ailun, a flight attendant with China Southern Airlines, was picking up her handset to answer a call last Thursday when she received an electric shock, police said Sunday, in reports carried by the state-run Xinhua news agency.

Police, who are continuing their investigation, have not yet identified a cause -- whether the phone or anything else.

In a statement received by CNN, Apple said: "We are deeply saddened to learn of this tragic incident and offer our condolences to the Ma family. We will fully investigate and cooperate with authorities in this matter."
Why did Apple apologize to China?
Why is China upset with Apple?

Many have taken to to social media to question how the 23-year old from China's far-western Xinjiang Uygur Autonomous Region died.

"(I) hope that Apple Inc. can give us an explanation. I also hope that all of you will refrain from using your mobile devices while charging," a person identified as Ma's sister posted on Weibo, China's Twitter-like service.

Meanwhile, Ma's father, Ma Guanghui, said that his daughter was electrocuted, adding that her body showed signs of electrocution, Xinhua said.

But Monday's Xinhua report also pointed out that mobile phones have a low output of only 3 to 5 volts, which isn't enough to harm the human body.


Note that even sites like Mike Holt's forum reported that you couldn't be electrocuted from an iPhone power supply because it outputs only 5 volts. But they weren't aware that failed insulation between the primary and secondary circuits from physical damage or even water can create a low-impedance path from the 120-volt line to the secondary chassis ground. Apple got out of the lawsuit on this case because the victim used an aftermarket charger, not an actual Apple product. I had contacted Apple at the time of this electrocution, and they weren't interested in discussing the dangers of using a charger in a shower since it wasn't their brand charger. However, I think that ANY charger that's damaged or submerged in water COULD have it's line-to-output insulation compromised and present a shock/electrocution hazard. I'm not going to try this myself.

john lutz

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Re: How can I have 35v to ground ?
« Reply #12 on: September 27, 2014, 08:33:20 PM »

Open or high resistance ground connection.


Steve

Yup, found it. 
One of the outlets on the power strip had a dodgy ground recepticle.  If the power amp cord was plugged in just so.... it would loose connection.  I thought it was the switch somehow, but that made no sense. 
Thanks.
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Stephen Swaffer

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Re: How can I have 35v to ground ?
« Reply #13 on: September 27, 2014, 10:30:19 PM »

That's true for undamaged double-insulated appliances. But as you hinted, there's been at least two electrocutions this year from iPhone chargers that were damaged and passed a lot more than micro-amperes of leakage current. People standing in the shower while touching their iPhone that were plugged in for charging were electrocuted. There had been some damage to the chargers, since they really do get beat up. So you never know when something is going to fail. I, for one, would never touch anything plugged into a wall outlet while standing in water. Seems like a really bad idea to me. 

I was scanning my 2014 NEC today and noiced one change was mandating GFCI receptacles within 6 feet of a shower-I guess this explains why it made it into code, though it seems since they were required within 6 feet of sinks already, common sense would include showers?

Speaking of common sense-it is an iPhone charger which means is a battery powered device, and that battery would presumably last long enough to take a shower.  Why would you have it plugged in while taking a shower?  Darwin must be hard at work here!
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Steve Swaffer

Steve M Smith

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Re: How can I have 35v to ground ?
« Reply #14 on: September 28, 2014, 03:50:24 AM »

Speaking of common sense-it is an iPhone charger which means is a battery powered device, and that battery would presumably last long enough to take a shower.  Why would you have it plugged in while taking a shower?  Darwin must be hard at work here!

My question is - how would you plug in the charger in a bathroom?  Here in the UK, the only outlets allowed in a bathroom are for electric shavers and they are transformer isolated.

Apart from the obvious question - why would you even need to take your i-phone into the shower?!!


Steve.
« Last Edit: September 28, 2014, 03:53:21 AM by Steve M Smith »
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Mike Sokol

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Re: How can I have 35v to ground ?
« Reply #15 on: September 28, 2014, 08:13:46 AM »

My question is - how would you plug in the charger in a bathroom?  Here in the UK, the only outlets allowed in a bathroom are for electric shavers and they are transformer isolated.

Apart from the obvious question - why would you even need to take your i-phone into the shower?!!

Steve.

This answer is: You need your iPhone in the shower while you're working on the circuit breaker panel.

John Roberts {JR}

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Re: How can I have 35v to ground ?
« Reply #16 on: September 28, 2014, 11:35:27 AM »

I thought that Chinese flight attendant death was old news...any date on that CNN report? Woman killed in a bathtub by a knock off I-PHONE battery charger that clearly was not safe.

It was such a big deal for the brand image that Apple gave customers new Apple battery chargers for any old apple or non-apple chargers they brought to stores. 

JR

PS: My house is not remotely to code but I added GFCI to the one outlet in my bathroom and the one by my kitchen sink. I have one GFCI left over, I may put in my laundry room (or use it to replace one of the first two when they fail). 
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Steve M Smith

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Re: How can I have 35v to ground ?
« Reply #17 on: September 28, 2014, 03:45:16 PM »

PS: My house is not remotely to code but I added GFCI to the one outlet in my bathroom and the one by my kitchen sink. I have one GFCI left over, I may put in my laundry room (or use it to replace one of the first two when they fail).

Is it not standard practice to have a GFCI on the whole system?


Steve.
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John Roberts {JR}

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Re: How can I have 35v to ground ?
« Reply #18 on: September 28, 2014, 04:56:27 PM »

Is it not standard practice to have a GFCI on the whole system?


Steve.
Not in Hickory MS in a cheap old house. Perhaps for new builds.

In Europe it is pretty common to have RCD interrupters on every branch, I still have screw in Edison base fuses. When I bought the house there were a bunch of 30A fuses in the box that may not be legal. I think code limits branch current to 20A, Since then I have replaced the 30's with 20A fuses. 

JR
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Jonathan Johnson

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Re: How can I have 35v to ground ?
« Reply #19 on: September 28, 2014, 10:39:40 PM »

Apart from the obvious question - why would you even need to take your i-phone into the shower?!!

Because you are addicted to your online presence. That's one of the reason that pedestrian-automobile accidents seem to be rising, people walk into light poles, and into decorative fountains in shopping malls.
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Re: How can I have 35v to ground ?
« Reply #19 on: September 28, 2014, 10:39:40 PM »


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