Can a neon sign transformer with an output of 12000V and 30mA kill you?

[Florin]

I just saw a video https://youtu.be/EOVpldbaGq4?t=24s where this transformer is limited to 30mA and I was wandering if it can kill you.
(PS: It's my first post and i'm not sure if i choose the correct category).

[dfmischler]

If you grabbed one lead in each hand while it was running it could very well kill you, if it can actually achieve 30 mA in that situation.  Some people say that it "should" take more current to kill you, but there are a lot of variables including your own medical condition.

[German_EE]

Assume YES unless you have absolute proof that this is not the case.

[Florin]

But, for example, if a transformer will be limited to, let's say, 1 - 10 mA or even lower it will be safe regardless of the output voltage?

[Zero999]

If you grabbed one lead in each hand while it was running it could very well kill you, if it can actually achieve 30 mA in that situation.  Some people say that it "should" take more current to kill you, but there are a lot of variables including your own medical condition.

Yes, there's a risk of death and serious injury such as burns and damage to the heart and nervous system.

An RCD my trip at 30mA but the current doesn't flow for long.

[German_EE]

It always depends on your attitude and training to electrical safety. I was always taught that any electrical device operating above 50V is dangerous unless proved or labelled otherwise.

[SteveyG]

That's about 360W, so well into seriously dangerous depending on duration of contact

[dexters_lab]

But, for example, if a transformer will be limited to, let's say, 1 - 10 mA or even lower it will be safe regardless of the output voltage?

safe? i would not call it safe by any means, even a few mA at 12kv will burn you at least

[xygor]

Yes, in several ways.
If it electrocutes you, a bigger one could resuscitate you.
If you ingest it, it could kill you.
If it falls on you, it could kill you.
If you collide with one, it could kill you.
If you stole it, the owner could kill you.

[Brumby]

I just wouldn't tempt fate.  I'd give 12kV some respect.

Even if you get a zap that won't kill you, it is still uncomfortable and can cause you to instinctively react.  That reaction won't be a well thought out movement and you could do something that results in more dire consequences.

[retrolefty]

From the Wik:

Magnitude[edit]
The minimum current a human can feel depends on the current type (AC or DC) as well as frequency for AC. A person can feel at least 1 mA (rms) of AC at 60 Hz, while at least 5 mA for DC. At around 10 milliamperes, AC current passing through the arm of a 68-kilogram (150 lb) human can cause powerful muscle contractions; the victim is unable to voluntarily control muscles and cannot release an electrified object.[5] This is known as the "let go threshold" and is a criterion for shock hazard in electrical regulations.
The current may, if it is high enough, cause tissue damage or fibrillation which leads to cardiac arrest; more than 30 mA[6] of AC (rms, 60 Hz) or 300 – 500 mA of DC can cause fibrillation.[7][8] A sustained electric shock from AC at 120 V, 60 Hz is an especially dangerous source of ventricular fibrillation because it usually exceeds the let-go threshold, while not delivering enough initial energy to propel the person away from the source. However, the potential seriousness of the shock depends on paths through the body that the currents take.[7] If the voltage is less than 200 V, then the human skin, more precisely the stratum corneum, is the main contributor to the impedance of the body in the case of a macroshock—the passing of current between two contact points on the skin. The characteristics of the skin are non-linear however. If the voltage is above 450–600 V, then dielectric breakdown of the skin occurs.[9] The protection offered by the skin is lowered by perspiration, and this is accelerated if electricity causes muscles to contract above the let-go threshold for a sustained period of time.[7]
If an electrical circuit is established by electrodes introduced in the body, bypassing the skin, then the potential for lethality is much higher if a circuit through the heart is established. This is known as a microshock. Currents of only 10 µA can be sufficient to cause fibrillation in this case

[uncle_bob]

I just saw a video https://youtu.be/EOVpldbaGq4?t=24s where this transformer is limited to 30mA and I was wandering if it can kill you.
(PS: It's my first post and i'm not sure if i choose the correct category).

Hi

Here's the trick that you may see:

You take the neon driver transformer and convert it's output to RF (with a Tesla Coil). You get marvelous looking arcs. The current can be quite high. Since it's RF, your body reacts differently to it than to DC or low frequency AC. You can still get burns (energy -> heat). You don't get the same interaction with the nervous system. It's a great way to do dramatic demo's. It's also a good way to give people the wrong impression about electrical safety.

30 ma at a couple of KV (DC or low freq AC) will knock you across the room from the muscle contraction.(no it does not knock you, your muscles knock you, the result is the same and it hurts). Yes I have empirical data ...

Bob

[janoc]

Oh and don't forget the lovely deep burns through the tissue where the arc has shot through. Those take very long time to heal and if they get infected because of the dead tissue deep in the muscle, you can end up with sepsis or an amputation.

That is not a voltage to take on lightly, even if it was just 1-2mA and not 30.

 

[CatalinaWOW]

The following link implies that neon signs have killed at least one person, but probably not dozens and dozens.  (It is interesting reading overall on the topic of electrical safety.)

http://apps.ocfl.net/dept/county_admin/public_safety/risk/Construction_Workers_Getting_Electocuted.pdf

Anecdotes from people on various forums (including this one) show that many people survive contact with these supplies.  All mention that it was absolutely no fun.  Very painful and frightening.  My own experience with a lesser source confirms this.

Seems like treating it as if it could kill you is a smart move.  Even if you don't save your life you will avoid a lot of pain.

[Brumby]

Anecdotes from people on various forums (including this one) show that many people survive contact with these supplies.

That has been said on many occasions about supplies that are eminently capable of killing.  Any reader should not take that as an observation, not an invitation to regard them with any less respect.

[calexanian]

Yes. It can..

[rs20]

Anecdotes from people on various forums (including this one) show that many people survive contact with these supplies.

That has been said on many occasions about supplies that are eminently capable of killing.  Any reader should not take that as an observation, not an invitation to regard them with any less respect.

Indeed -- many people have survived Russian roulette... Obviously doesn't make it safe!

[station240]

Reminds me of a story about someone who found a fallen 11KV cable draped over the road through a puddle. He figured as it wasn't arcing and making a noise it was dead, so they coiled it up by the side of the road.

Power company showed up at that point, told him off and tested the cable. Yup live at full 11kV AC, seems that sort of voltage doesn't always kill you outright, can simply burn your insides up. Very worried driver left about 30 minutes later.

[f4eru]

Yes it's definitely lethal:



The high voltage leads to ensure a very high current will go through a human, even with a pretty high resistance (ie, you don't need a wet hand as with lower voltages)

By the way, if a transformer is marked "30mA", this is a continuous rating. In the case of a short circuit, (for example through the "low" resistance of an human), it will happily supply 10-50x more -> 300mA to 1,5A.

To these lethal effects of electric current, at that high voltages and high current, the heat of the arc will burn flesh.

A coworker of me had a hole through his hand with a source that was 5-10 mA @ 5KV AC. Material defect in an isolator. The arc got through his hand

Don't play with it.

[f4eru]

FYI, the guy in the video is really handling it unsafely :
at 0:25 he is handling at the same time both sides of the high voltage output with no proper insulation:

- The gloves are probably not rated for 12KV
- The wires are 100V wires.... Just don't.
- He is grabbing the wires. That's dangerous because in case of shock he will not be able to let go.
- He is handling both sides at the same time. Don't do that.

....no comment.

[Halcyon]

Let's err on the side of caution on this one. 'Tasers' output ~1200VDC upon contact (unsure of the amperage). They have been known to kill people who have major heart defects, on drugs etc... etc... They call it a "less than lethal" option for a reason. A more politically correct description could be "It might kill you... just depends".

[KE5FX]

By the way, if a transformer is marked "30mA", this is a continuous rating. In the case of a short circuit, (for example through the "low" resistance of an human), it will happily supply 10-50x more -> 300mA to 1,5A.

Actually neon sign transformers are designed to limit their output current at the rated figure via core saturation.  The neon tube will look like a low-resistance load once the gas ionizes, so an external series resistor would otherwise be necessary to keep from blowing a fuse, the tube, or the transformer.  Even at only 30 mA, though, it's nothing to take lightly.  People absolutely can be killed, and have been, by that much current.

I think the scariest thing I've seen on YouTube was a video where some idiot connected a couple thousand 9V batteries in series without even the faintest recognition of the hazard of insulation breakdown.  You can get 500 mA from a 9V battery for a few seconds.   

[HighVoltage]

30 to 50 mA is the typical current coming out of an ignition coil for cars at about 30 to 40 kV.
And these cars usually have a big yellow warning label in the engine compartment, warning about the high voltage.
There are probably thousands of people who have been zapped by such a high voltage current discharge but I am not aware of anyone who died from it. But this kind of discharge is just a small pulse, may be a milli second long and not comparable to a Neon transformer.

12kV at 30mA might kill you, depending on how long it is applied and what condition the person is in.

What I always find interesting is that science makes a difference between the gender, when it comes to current discharge in to the body.
Enclosed are a few tables.

[SteveyG]

Reminds me of a story about someone who found a fallen 11KV cable draped over the road through a puddle. He figured as it wasn't arcing and making a noise it was dead, so they coiled it up by the side of the road.

Power company showed up at that point, told him off and tested the cable. Yup live at full 11kV AC, seems that sort of voltage doesn't always kill you outright, can simply burn your insides up. Very worried driver left about 30 minutes later.

Explanation is likely step potential due to the wet ground, so basically no potential difference between the cable and the body of earth around him = no shock.

[Srbel]

A few mA stops the hart.