Electric shock

can you get electric shocks off PV systems. I am trying to understand the mechanics and was wondering at what point in a scale do these panels pose a threat to giving a deadly shock, if you were to handle them in a way that you came in contact with the wiring. My experience is that a car battery does not give a shock, however I imagine putting batteries in series would eventually lead to a hazard, like wise PV panels.

Comments

  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Electric shock

    actually, it isn't the voltage that kills you, but the current and only about 35ma is needed to pass through the heart to do it if memory serves. a battery can most certainly provide that current. the voltage comes into play in overcoming resistive losses making that current much more likely to occur. the nec draws a line of about 50v, but one can accidentally touch say 120vac and be fine and the next incident hit 48vdc just right and suffer a shock that could induce death. respect it all.
  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    Re: Electric shock

    Ditto, The human skin, on average, (clean, dry) is high enough resistance, that 12 & 24 are nearly completely safe, and as you get higher voltages, a little more current flows. NEC draws the line at 50V, beyond that, it's a fairly sure thing you can "feel" it. 10mA [.01A] thru the heart muscle, is all it takes to screw it up.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • FreeBrrd
    FreeBrrd Solar Expert Posts: 116 ✭✭✭✭
    Re: Electric shock

    Years ago when I was working as a small engine mechanic, I got my metal watchband across battery on a riding mower. It burnt a hole in my wrist under the watch, watch didn't work any more either. I've never worn a metal watch band since unless I'm getting dressed up (and hopfully not working around batteries). Someone else had to pull the watch off. Didn't shock me, but burnt me.
  • nigtomdaw
    nigtomdaw Solar Expert Posts: 705 ✭✭
    Re: Electric shock

    12v unless u lick the poles at the same time nothing, pretty much the same at 24v but you start to get a tingle at 48 volt. Plus please remember a 48v nominal array in VOC is more close to 70v and u will get a more than a tingle at this level. I got a belt from a nominal series array at 72v voc 104 v and u are well aware of it. Its differnet from Ac where you get a muscle wobble at 50 or 60 Hz more of a constant buzz thats not comfortable.


    I guess the experts will frown at my observations but as I advise higher nominal system voltages DC Im learning to respect the power these systems can pass through the carbon life form. IE Me :blush:

    But Im not the first or last to not respect PV power as low volume output or input, would I grab my live terminals from my 2.4kw array on a cool sunny day at 24v not on your Nellie.
  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    Re: Electric shock

    Why is it that motorcycle batteries have such a great affinity for metal. A co-worker somehow got his wedding ring welded to his motorcycle battery, and it literally cooked his finger off. No saving that digit.
    So why do they say to tape up wrenches and such when working around batteries ...
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,