How Dangerous is 24vdc at 30 milliamps ?  ?

I’ve heard the saying it’s not the volts , but the amps that kill , I’ve also heard it’s mostly the volts , my understanding is it’s a combination . 

9 Answers

  • 1 month ago

    If it was 30 milliamps through your body, yes, it would kill you. But it's not. The current depends on the resistance of the circuit. That figure of 30 milliamps comes from measuring whatever circuit you got that figure from.  If you added a human being in series in that circuit, the resistance of the circuit would be far, far higher, and the current would be tiny. A current of a few milliamps across your heart, can kill you. But it takes a much higher voltage to drive that much current through the resistance of a human body.


  • Steven
    Lv 7
    1 month ago

    Most people can not feel 24Vdc. Skin resistance is about 10K Ohms so 24V can not cause more than 2.4mA through a human body. It would require about 30mA*10KOhms=300 Volts to cause a body current of 30mA.

    Safety depends on the fusing or breaker. An unfused 30mA supply may cause a fire if it is loaded/shorted to, say 300mA, while a 1 Amp supply can operate safely at that current. But in many cases, a low power fault condition like 24V*30mA=0.72 Watts can be safely dissipated without much protection.

    It's important to understand that the current rating is just the nominal operating limit and unlikely to be the actual current.

  • Jim
    Lv 7
    1 month ago

    Nope, probably not an issue! While any amount of current over 10 ma is capable of producing painful to severe shock, currents between 100 and 200 mA are lethal. Also, you typically need >50v to achieve that!

  • Anonymous
    1 month ago

    Not very,

    unless you probe the inside of the body.

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  • Dixon
    Lv 7
    1 month ago

    It is safe. You would need to push the wires through your skin to get electrical damage. You might get a tingle from touching on the surface of the skin and don't put 24V on your tongue.

  • 2 months ago

    The danger is the combination of Volts times Amps which is power and causes cooking burns of the body.

    A current of 1 to 3.5A can stop the heart if it passes through the chest area. The body resistance is about 10K ohms so it would take 10,000 to 3,5000V to do that. Generally DC Voltage causes burns and AC Voltages cause nerve damage and heart arrest and brain damage.

  • 2 months ago

    Look at it this way. The amps are what kill you but it is the volts that push the amps through your body. So it takes a combination of the two to be deadly. You have to have a high enough voltage to do the pushing and enough amperage to do the damage. 

  • 2 months ago

    24 volts is below the hazardous voltage limit. Current is that determined by the body resistance and the voltage. Currents above about 10 mA are painful, currents above about 100 mA can kill.

    A 24 volt 10 amp supply is not more hazardous than a 24 volt 100 mA one, in fact neither are hazardous except under unusual circumstances. 24 volt 30 mA is even less hazardous than those.

    A 200 volt 10 amp supply is not more hazardous than a 200 volt 100 mA one and both can be lethal.

    Bottom line, current is what kills, but current is determined by voltage and body resistance, I = E/R. Current thru your body is NOT the max rating of the supply, but by the calculation above.

  • Anonymous
    2 months ago

    pretty safe

    Volts and amps always go together. If one doubles or triples, so does the other

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