Discussion in 'The Projects Forum' started by Thanks4helpin, Oct 10, 2015.

1. ### Thanks4helpin Thread Starter New Member

Mar 14, 2012
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Could you kindly look at the attachment with the questions which I just made in powerpoint to illustrate my question? Again this is an important question and there are good reasons for me asking it. I've been very curious about the voltage/current of the master power strip plug vs plugs that go into the power strip (from various devices). All three questions assumes the power strip is turned on, not off. It is not a surge protector.

My hypothesis is :
In the scenerio of question 1, the shock would be the same from A or B?
In the scenerio of Question #2 the voltage/current is higher for A (leading to greater shock) vs B and C, because A should have double the voltage/current to provide evenly between B and C? Because B and C are drawing power? This is assuming B and C are drawing power to similar machines, for example one vacuum cleaner each, because i know different appliances use different amounts of power.
In the scenerio of Question #3, my hypothesis is that A will lead to a greater shock, approximately double that of touching B?

I do not intend of course, to try anything to test this out nor do I have any intention of hurting anyone or myself. I am literally asking a question that is eating at my curiosity due to my OCD. Please answer specifically in non-scientific terms and I appreciate your help! Previously some geniuses have helped me answer my
questions and I really really appreciate it and am grateful. So Thank you in advance.

LAST QUESTION #4) Imagine the power strip is on an both plugs B and C are drawing power to their respective machines which are On. what happens if a person touches the prongs of B AND C (four in total) in one hand? How will the electrical path look like? will it still be two separate electrical paths, one among B (from first prong of B to second Prong) and one among C (from first prong of C to second prong)? or will they connect somehow? I'm not looking for answers of person will die etc etc, I'm asking the effect it will have as to the electrical path through the hand.

2. ### Alec_t AAC Fanatic!

Sep 17, 2013
5,976
1,136
Do not touch the prongs of any of those plugs! You risk getting the same FATAL shock regardless of whether the devices plugged in are switched on or not.

3. ### MikeML AAC Fanatic!

Oct 2, 2009
5,451
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A is electrically connected to B through an intervening (usually 15A) circuit breaker mounted inside the plug-strip, and is at 120Vac with respect to earth ground.

Touching A or B with one hand and touching an earth-grounded object with the other hand will shock you equally, unless the C.B. is tripped, in which case B will have no voltage on it.

All other prongs are at 0V, so touching them will not shock you....

Plug strips (the kind with the high-voltage transient suppression) should never be operated without the ground prong connected to the wall socket, either by cutting off the round prong, or by using a three-prong to two-prong adapter!

If you do, the chassis of any three-prong appliance plugged into the Plug strip will give you a shock if you touch the appliance with one hand and touch an earth grounded object with the other hand.

Last edited: Oct 10, 2015
4. ### Alec_t AAC Fanatic!

Sep 17, 2013
5,976
1,136
When it comes to mains power plugs and sockets it is safest to assume that ANY pin can give you a shock (in case some eejit has been tinkering without your knowledge).

5. ### GopherT AAC Fanatic!

Nov 23, 2012
6,315
4,037
@Thanks4helpin

Each connection is only about 0.1 ohms of resistance. Your skin is about 250,000 ohms of resistance that is in series with the 0.1 ohms of resistance.

Now, the current flowing through A, or B or C will be the same for all practical calculations.

That is, current A = 120/1000.0
B = 120/1000.1
C= 120/1000.2

About 0.120 amps (120mA) is definately enough to kill. Note that current can flow in many ways one it touches your skin. Through the wet tissue (1000 ohms or less) or along moist sweaty (salty) skin (about 1000 ohms) or over dry tissue (much more than 1000 ohms initially, until better paths are created).

In any case, you can see by calculating the value of A, B and C, the difference is, "not much".

Good luck.

6. ### KeepItSimpleStupid Well-Known Member

Mar 4, 2014
1,278
224
The power strip, drawing power or the outlet are all irrelevant.

The relevant parameters can change on a whim:

You skin conductivity/resistance. This varies A LOT.

The effective resistance to a grounded object.

Whether or not you touch the HOT side (narrow blade) and nothing else is defective. the wode blade and the circular terminal is in theory 0 volts.

One finger touch to the narrow blade and standing on a wet floor could cause a shock.

"Tamper proof" outlets prevent both hot and neutral to be contacted with an object unless they are pressed simultaneously.

Mar 14, 2012
19
0