Reverse Polarity Changeover Unit

Discussion in 'Motorhome Chat' started by canopus, May 15, 2011.

  1. canopus

    canopus Funster Life Member

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    My mate Graham has one of these polarity sensing devices in his van and when he connects his Kippor generator, both LED's are illuminated and the buzzer sounds on the device. Has anyone experienced this phenonemon and is the supply safe? Tried my Kawasaki genny with similar results. Any advice would be much appreciated.:cry:
     
  2. Reallyretired

    Reallyretired Funster

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    This is probably because there is no earth on the generator output. If so this is normal.
     
  3. M1TCH

    M1TCH Read Only Funster

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    Thanks Ken for posting the question and thanks for the answer, i tried an earth rod in the ground connected to the earth point on the genset but no change both lights are on and the buzzer sounds, my next question is if i can`t cure this is it safe to use, i can live with the buzzer its in a wardrobe so can`t hear it when the doors shut i just don`t want to damage anything including the change over box thanks Gray. :thumb:
     
  4. canopus

    canopus Funster Life Member

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    Im sure it will be safe to use otherwise generator manufacturers would go out of business. The sensing device in your van must need a reference to earth to function correctly. As you saw on the Martindale plug in tester, the genny only has live and neutral displayed.:Doh:
     
  5. JayDee

    JayDee Funster

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    Not a lecky, but it seems to me that the genny earth would need to be linked to the motorhome earth for the polarity sensor to read true. I imagine that the genny would need to be earthed as you tried and the MH earth connected to to the same point. But don't take that as gospel - I'm just an enthusiastic (still alive!) amateur. :RollEyes:


    John
     
  6. Jaws

    Jaws Funster Life Member

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    I do not know for sure.. but I THINK it is caused by the following.

    Most modern genny's produce 12v or 24v which is fed in to an inverter

    All modern inverters put out a pure sine wave..

    I have a feeling all the so called polarity detectors ( which of course they are not as AC does not have poles as such ) cannot 'see' what they are looking for, so will either ignore the sine wave completely or worse, think that it is connected to something that is dc as the rise and fall rates are identical ( due to the output being pure sine )
     
  7. M1TCH

    M1TCH Read Only Funster

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    I thought that, but im not a sparky either just a lowly joiner, its been said i could not join a Christmas club :Rofl1:, im not keen on mixing AC with DC earths if you know what i mean :Confused: Gray.
     
  8. Jaws

    Jaws Funster Life Member

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    CQ CQ ? de G4VEL :BigGrin:
     
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