Shock or No Shock on neutral bonded portable generator

Discussion in 'General Electronics Chat' started by John Samuel, Nov 4, 2015.

  1. John Samuel

    Thread Starter New Member

    Nov 3, 2015
    2
    0
    Consider a portable generator whose non-current carrying metal parts(such as fuel tank, internal combustion engine) and the equipment grounding conductor terminals of the receptacles mounted on the generator, bonded to the generator frame and the Neutral conductor also bonded to the frame.I hope this is the floating ground configuration of a bonded neutral generator.If someone were to touch a grounded part of this equipment housing while making good contact to ground, will they get a shock?


    The link to the article which promped this question is http://www.screenlightandgrip.com/html/emailnewsletter_generators.html

    .Please look under the heading "Bonded Neutral Generators".
     
    Last edited: Nov 4, 2015
  2. MaxHeadRoom

    Expert

    Jul 18, 2013
    10,548
    2,373
    In theory no, because the generator output is not referenced to earth ground.
    Max.
     
  3. John Samuel

    Thread Starter New Member

    Nov 3, 2015
    2
    0
    Max,
    The article says of the possiblity of a shock." They could receive a slight shock equal to the difference in potential between the arbitrary floating power source and ground."

    You said theoritically it is no.Is there a practical scenerio where there is a possiblity of shock?

    Thanks
    John
     
  4. MaxHeadRoom

    Expert

    Jul 18, 2013
    10,548
    2,373
    There is always the possibility of leakage of some kind, depending on the equipment being fed.
    e.g. if a live conductor was leaking or came in contact with earth ground of some kind.
    Max.
     
  5. MikeML

    AAC Fanatic!

    Oct 2, 2009
    5,450
    1,066
  6. recklessrog

    Member

    May 23, 2013
    338
    102
    That is not the full picture, In a lot of generators of the small portable type, there is no true "neutral." Both terminals are floating and APART from normal wiring convention to the terminals of the output sockets, either lead can be either live or neutral (both live like the secondary of a transformer until you start connecting it to something else) Depending on the configuration of the generator, be it purely alternator or alternator/inverter, the manufacturer will recommend the preferred method of earthing. It is usual in outdoor portable use to put a good copper earth spike into dampened soil and connect it to the frame earth terminal on the generator. Follow the generator manufacturers guide and you should be ok, but strange things happen when powering reactive loads from some so called sinewave generators. The output waveform from some, is more like a squarewave that changes depending on the type of load. The reasons for this are complex and is beyond the scope of a quick response here. Power factor correction in some cheap generators is almost non-existent.
    Beware of the cheap import "copies of well known makes" They are a fraction of the cost of the genuine article
    and so is their true performance.
     
  7. ErnieM

    AAC Fanatic!

    Apr 24, 2011
    7,392
    1,605
    Short answer is it is possible to get a shock.

    You do not state the gen frame is earth grounded so there is no assurance it is at earth potential. With gen loads typically being assembled on site with little planning it is easy to get something wrong, or portable equipment can get frayed wiring, or lots of other things can go wrong to electrify parts of the system that should not be powered.

    Hey, a large static charge has no where to go in a floating system.
     
Loading...