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otrfun's avatar
otrfun
Explorer II
May 03, 2013

Using Clamp-On Multimeter to Check a/c Surge Current

I'm thinking about purchasing a Yamaha EF2400iSHC generator to power my 13,500 BTU a/c. I know the odds are in my favor that it will work, but ya never know.

Some of you have mentioned using clamp-on multimeters to check your a/c's surge current. Can any of you shed some light on which clamp-on multimeter you used and what your results were? Is anybody aware of a particular continuous or surge current reading that tends to exceed the capability of the EF2400iSHC? I know the EF2400iSHC is supposedly rated at 16.7 amps continuous and 20 amps surge. However, I've read here and there the EF2400iSHC can sustain a 30+ amp surge for 5 to 10 seconds.

I noticed Harbor Freight sells some cheap clamp-on multimeters with a "peak" function. Are these a complete waste of time and money? Or, should I invest in a more expensive unit that has the "inrush" capability? I'm thinking it might be worth the $100-$150 investment to increase my confidence the EF2400iSHC will work with my a/c unit.

Thanks!

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  • MNtundraRet's avatar
    MNtundraRet
    Navigator
    May 03, 2013
    In order to use an AC/DC clamp-on meter to do AC current (amps) you will need an extra option (device) called an AC line splitter.

    Measuring amps in DC is easy since the clamp only goes around one wire ("pos" or "neg"). Since you do not want to rip apart an AC power cord to separate the wires for a Clamp-on meter, the device plugs into an AC cord on each end to allow the clamp to go over one wire cable only.

    If the Air-conditioner is "hardwired", you need to find where the wires are separated inside the unit and check the current there. Be careful to follow all warnings since this is can be more dangerous than a simple DC, 12v amp check.

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