Click for Furuno Click for Cross Click for Northern Lights Click for Westport Click for Comfort

Dumb electricity question

Discussion in 'Technical Discussion' started by Blue Ghost, Mar 19, 2015.

You need to be registered and signed in to view this content.
  1. Blue Ghost

    Blue Ghost Member

    Joined:
    Feb 22, 2012
    Messages:
    299
    Location:
    The Regina systen in the Spinward Marches
    Okay, so if an American like me charters one of the big yachts cruising the Med or Aegean Sea, and I bring my lap top, what kind of electrical adapter do I need to plug into the ship's electrical?
  2. captholli

    captholli Senior Member

    Joined:
    Jan 4, 2010
    Messages:
    1,164
    Location:
    In The Bilge
    None, Your lap top's electronic power supply will accept voltage from 110 v to 240 v 50 or 60 Hz.
  3. CL-Yachts

    CL-Yachts Senior Member

    Joined:
    Feb 24, 2009
    Messages:
    16
    Location:
    Fort Lauderdale
    You may still need Euro plug adapter. Something like this:[​IMG]
  4. Blue Ghost

    Blue Ghost Member

    Joined:
    Feb 22, 2012
    Messages:
    299
    Location:
    The Regina systen in the Spinward Marches
    Very cool. Thanks guys.
  5. Chasm

    Chasm Senior Member

    Joined:
    Mar 30, 2013
    Messages:
    137
    Location:
    Germany
    Always take a look at the small print on your power supply / device / appliance.
    A quick survey (Dell HP Fujitsu Samsung) shows that the voltage range most likely will be 100-240V 50-60Hz. In that case you only need a mechanical adapter for the plug. For devices without ground the one shown above is pretty much universal in the EU. - For grounded devices not so much.

    A bit more attention may be required in Australia there the actual voltage was 250V, and still is since thats the upper limit of the allowable tolerance.

    Be extra careful with USB chargers.
    Most of the cheap ones are fakes and potential firecrackers even in 110V areas.
  6. K1W1

    K1W1 Senior Member

    Joined:
    Sep 30, 2005
    Messages:
    7,388
    Location:
    My Office

    This website has a good list of what you get where and which plugs and sockets they use standard.

    http://www.worldstandards.eu/electricity/plug-voltage-by-country/

    It does show Australia as 230V single phase and as the 3 phase voltage is shown as 400V this would make sense.

    Even if they were at 415V they would still only be giving you 240v phase to neutral.
  7. Blue Ghost

    Blue Ghost Member

    Joined:
    Feb 22, 2012
    Messages:
    299
    Location:
    The Regina systen in the Spinward Marches
    Interesting site. It seems like most every other country is running 230V, whereas here in the states we're still at 120V except for our appliances. That's kind of strange. I wonder what the justification is for going 220, 230, 240 on all circuits.
  8. K1W1

    K1W1 Senior Member

    Joined:
    Sep 30, 2005
    Messages:
    7,388
    Location:
    My Office
    The reason is 1.732. The advantages are smaller cables and switch gear as the current is halved. More places use it so you don't have as many problems when traveling this is not such a biggie now with so many dual frequency things but used to be huge.

    Can you even begin to imagine how big a job it would be to convert the world to one standard electric supply and plug/socket set?
  9. olderboater

    olderboater Senior Member

    Joined:
    Sep 2, 2013
    Messages:
    7,132
    Location:
    Fort Lauderdale
    Wouldn't the better question be what is the justification for 110? And it's really that we were well ahead of most of the world in generating electricity and building plants. The early technology however did not produce light bulbs or other equipment that could handle 220-240. Lighting was actually the primary use of early electricity. By the time that was addressed we already had a rather sizable commitment to 120, but most of the rest of the world did not and was able to start at 220-240.
  10. Chasm

    Chasm Senior Member

    Joined:
    Mar 30, 2013
    Messages:
    137
    Location:
    Germany
    In the 1980s a worldwide program started to standardize the various 220-240V 50Hz voltage systems to 230V. Voltages in Germany got raised in 1990(?) from 220V to 230V nominal to deliver more power over the same wire. (In the US 110V to 120V.)

    240V nominal voltage areas (UK, AUS) were lowered to 230V. No actual changes for them, as 240V fit into the allowable tolerance band of +6/-10% at the time. (now +/-10%)
    Just as 230V fitted into the previous 220V +/-10% band. [Fun fact, gathering my facts for this post I came across an Interpellation concerning this change. One question was if 230V would reduce the life of incandescent bulbs.]

    230V+6% 243,8V
    230V+10% 253V

    The national standard in AUS seems to be 230V +10%/-6%.
    NSW and Victoria allow higher upper limits of 264V, or 240V+10%. Which is a bit hot and supposed to be adjusted down.



    Why 110V?
    One explanation is that a single carbon arc lamp used 55V, times 2 so that you don't need additional resistors and you arrive at 110V. - Which does not really work, as it was 110V DC at the time, not AC.
    Times 2 again to simply avoid patents on the other side of the pond and being a bit later (= better or at least more knowledge about insulation) and you have 220V. Which also instantly saves half of the required metal in the wiring, which is expensive.

    There is always an argument about safety, but thats a bit bogus. Touching 120V will simply kill you a bit later. Safety extra-low voltage, say for medial applications, is defined as under 50V AC.


    A bit of history.
    In 1909 my grandparents farmhouse got DC servivce. The village blacksmith had bought a steam engine and generator.
    In ? they were converted to AC
    In 1958 the local and so far isolated power grid got sold to and integrated into the municipal energy company.
    In 1964(?) the other grandpartents house, build in 54, got converted form poles to underground service.


    In the end, look at your device and read the fine print on the tag. It'll tell you which voltages it can handle.
  11. K1W1

    K1W1 Senior Member

    Joined:
    Sep 30, 2005
    Messages:
    7,388
    Location:
    My Office
    That is a great and informative post.

    You seem to have a handle on the electric business so maybe you can answer this.

    Why is there such a push to 110V Power Tools in the construction business if this is still a deadly voltage?

    It was rammed down our throats when this was being explained that no one had died from 55V AC.
  12. Blue Ghost

    Blue Ghost Member

    Joined:
    Feb 22, 2012
    Messages:
    299
    Location:
    The Regina systen in the Spinward Marches
    Isn't 110V just as deadly as 220?
  13. Capt J

    Capt J Senior Member

    Joined:
    Jul 11, 2005
    Messages:
    14,432
    Location:
    Fort Lauderdale
    110v is still deadly, but 1/2 as deadly as 220volts. :D Your chances of living through getting electrocuted from 110volts are quite a bit higher than getting electrocuted by 220 volts. Both can be very deadly.
  14. Chasm

    Chasm Senior Member

    Joined:
    Mar 30, 2013
    Messages:
    137
    Location:
    Germany
    Good question, AFAIK 110V tools are not a topic over here.
    On construction sites the rules require 30mA RCD on everything under 32A. (The industry has different rules.) Mobile tools have to be checked, measured and documented at least every 12 months by an electrician (or specifically instructed employee). On construction sites this is supposed to happen every 3 months but may be extended.

    All of that is done under the equivalent of OHSA rules.
    Then there are specific rules, say working in confined spaces. That's the only time I came in contact with an IIRC 48V SELV tool. A large impact driver used to work inside tanks.


    How much safer is 110V?
    I don't know. Don't really care either. ;)
    Skin resistance is voltage depended. Higher voltage, lower resistance - which is bad. It's not exactly linear which gives 110V a slight egdge.
    OTOH skin resistance is highly moisture depended. Dry skin, higher resistance. With thick callus even more. There are quite a few old electricians here in 230V country who checked their whole life for voltage with a finger. Experience as a child showed me that I tend to get shocked real good. So I use tools. ;)


    One of the not so obvious problems with electricity is that an electric shock can kill even hours after it happened. Something to keep in mind should someone ever "stick" to electricity. Esp. if you feel ANY symptoms. Nobody manages to call an ambulance once ventricular fibrillation sets in.
    Company rule was if you get shocked instant hospital, ECG and at least 12h observation, 24h+ if there are burn marks. (OSHA accidents are expensive, but much cheaper than the alternative.)
  15. Blue Ghost

    Blue Ghost Member

    Joined:
    Feb 22, 2012
    Messages:
    299
    Location:
    The Regina systen in the Spinward Marches
    Oh wow, I did not know that. I figured if you survived the initial shock, then even though you were shaken up you were okay. That's certainly something to think about.

    Quick story, I used to live very inland in the San Jouquin Valley as a boy, and a local convenient store had a very primitive coin-op video game. Only when you grabbed the handle you couldn't let go without really forcing yourself, and there was this tingly sensation accompanied with it.

    Years later I now understand that that thing had a an exposed wire somewhere, and that juice was probably flowing and spread out through the chassis and to the ground. I'm pretty sure the game is gone now, but it makes me wonder if anybody ever got severely injured from that.

    A few years back I had an electrician try and hunt down a short in the home. He was a licensed electrician from some Asian country. And this guy really scared the hell out of me by continually going to the breaker in the garage and turning on the juice and turning it off again to tinker with the dining room light. I had a broom handy ready to knock him on his backside if I saw he was getting electrocuted. I'll never forget it. This guy worked lightening quick; juice off, fiddle with wires, juice back on, test, juice off, fiddle with wires, again and again, almost running (the very fast Asian step thing) to and from my garage. I was sure he would forget at some point of when he had turned off the electricity.

    Well, he survived, but I was really scared as hell watching this guy work.
  16. karo1776

    karo1776 Senior Member

    Joined:
    Oct 18, 2011
    Messages:
    655
    Location:
    Gone
    The choices made in the various voltage and frequency in the early days of electrical engineering persisted because it is hard to change infrastructure... and the users infrastructure. There are advantages for each scheme and disadvantages.

    Electrical shock hazard is dangerous for any electrical power enough to do practical work other than operate electronics or small devices. Any wall plug in socket can produce death.

    For boats the most dangerous electrical voltage and frequency combination is absolutely 110-125v and 60 hz. but the real hazard is insulation resistance and that needs to be kept track of... to prevent accidents. Boat have a floating ground situation that can be particularly dangerous. Just like aircraft, particularly helicopters operated off boats can be very dangerous electrical shock hazards. The only place more dangerous is in the Arctic and Antarctic where grounds are squirrelly to obtain or understand.

    Why is 110-125v and 60hz turns out that voltage is enough to overcome most skin resistances but not enough to cause muscle reactions to release. You tend to clamp down if you grab a that voltage wire but if you grab a higher voltage wire it will effectively cause your body push back and release. As it turns out 60 hz. is the worst case for causing fibrillation of the heart. Now it is a matter of degree you will be just as dead with 50 hz but the probability of fibrillation is higher with 60 hz.

    The key is preventing you from becoming a conductor to ground, and increasing your resistance. Dry skin has high resistance and you might just get a nice wakeup but if you are slightly sweaty you might be dead.

    The only time in my life I have been shocked badly was doing a megger resistance check of a ultra sonic cleaner we had onboard... it had capacitors and I touched the bear plug end winding up the power cord after doing the check.

    When I was in the US Navy long time ago in charge of the electrical of a nuclear plant... I had many guys shocked badly because of stupidity. One hooked up a 440v 50 hp motor, checked for electrical safety... then that same guy later on watch checked the junction box for temperature by placing his hand on it... he was thrown across the compartment and severely shocked... came down to the EOS where I was in charge of the plant on watch... flushed and looking pretty shook up... too bad boy we don't have anybody to take your place go set down for awhile!
  17. Blue Ghost

    Blue Ghost Member

    Joined:
    Feb 22, 2012
    Messages:
    299
    Location:
    The Regina systen in the Spinward Marches
    Wait, so higher voltage is "safer" by virtue of the that it'll knock you back?

    Is that right?
  18. Capt J

    Capt J Senior Member

    Joined:
    Jul 11, 2005
    Messages:
    14,432
    Location:
    Fort Lauderdale
    Sort of. For example if you grab a live 220 volt wire, the voltage will make your muscles release and hopefully it will fall out of your hand. If you grab a 110 volt wire, you might just hold onto it and until you're completely fried as your muscles won't release.

    Karo's explanation was excellent and worded incredibly well.
  19. Blue Ghost

    Blue Ghost Member

    Joined:
    Feb 22, 2012
    Messages:
    299
    Location:
    The Regina systen in the Spinward Marches
    Well it explains why I had a hard time peeling myself away from that game way back in the 70s. It literally felt as if my hand and fingers were "frozen" to the controls, and I had this really weird sensation that almost went all over my body.

    Incredible. Thanks.
  20. Chasm

    Chasm Senior Member

    Joined:
    Mar 30, 2013
    Messages:
    137
    Location:
    Germany
    For the most part that is true.
    OTOH there is a risk, esp. if there are existing heart problems.

    I was next to one accident. The stereotypical wires in left and right hand accident in a lab. Checkup, and overnight stay for the apprentice at the instance of the employer.
    Another was an electrician who checked himself in. He worked at the bottom on an elevator shaft and "got stuck for way too long".
    Other anecdotal cases involve other injuries. Major burns after sticking a hand between 800V bus bars, broken bones from falling of the ladder after a small shock. And so on.

    Reality is of course nobody goes to the Doc for a small shock.
    However of you are dizzy, feel pain/cramps in your chest or other symptoms better get checked. As I understand it as long as the ECG is clean and they can't find burn marks (feet!) you are free to go home. If you had heart problems or risk factors you'll stay a while. Same for marks, if they exist quite a bit of energy passed through your body.


    Megger (insulation tester) ouch. Only sounds like "fun" from a distance.
    Too much beer, a pasture fence and NOT going first was also a good learning experience. (electrified fence, about 10kV over here) The dangers of rural life.