how many amps?

Discussion in 'Tech/Mech General' started by pappajohn, Nov 23, 2007.

  1. pappajohn

    pappajohn Funster Life Member

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    To get 7amp from my onboard charger/power supply(thats what its rated at)how many watts/amps must i put in, either mains or genny.
    my current genny is a 650w cont, 800w peak and it dont seem to be up to it.
    also can i use the gennies 8amp dc battery charge facility AND still connect the genny to the 240v mains socket without having to turn off the onboard charger.
    thinking of getting a 2.2kw pure sinewave kipor so i can run the aircon when off hookup.

    john.
     
  2. olley

    olley Funster

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    Hi papa 7amps at 12volts is 7*12=84watts 230v divided by 84watts is 84/230=.36 of an amp at 230volts so a 650watt genny should walk it.

    In answer to the second question I would no due to different maximum voltaged

    Charge rate is voltage dependant, if your battery is fairly well charged no matter how many amps you have available it will not make any difference. For instance I have 3 batteries totalling 580amph even when nearly flat the maximum charge is never over about 105amps from the alternator, I recken 20% of battery capacity is normally about your maximum charge rate, and a lot less as the battery reaches it fully charged state.

    Olley
     
  3. GeorgeTelford

    GeorgeTelford Deleted User

    Hi John

    Olley as summed up the onboard "chargers" power requirements, it is generally not worth attaching the 12v output from gennies unless using it as a power supply because it is usually only 12v output, to charge effectively the voltage needs to be higher.

    What model is your air-con? or the BTU's? The reason I ask is that the start up current on compressors can be quite high, in some cases the compressor uses over 3 X the normal operating wattage on a fridge, I cannot remember the exact figures for starting Air con but I seem to remember it was 5 X running current..
     
  4. pappajohn

    pappajohn Funster Life Member

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    i'll get back to you on that George. cant remember the make off hand(poss ELECTROLUX) but i think it needs 1.7KW which is 7amp at 240v.
    if im right and your estimate(X5) is correct then it will need 35amp to start.
    on hookup its on a 16amp mcb thru a 32amp 30ma rcd main switch. neither of which trip out with aircon running.
    the genny im thinking of has a rated output of 2.2kw and peak of 2.6kw.

    john.
     
  5. pappajohn

    pappajohn Funster Life Member

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    cheers olly.

    john.
     
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