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Thread: Poss. Ground problem, PSU shocking me

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    Question Poss. Ground problem, PSU shocking me

    I have a 400W inverter powered directly from the battery. The ground goes to a place I sanded to the metal and screwed directly into, what is basically, the floorboard. Now whenever if the PSU is powered on and I'm touching any part of the truck body and the casing of the PSU at the same time, I get a slight shock. Nothing heart stopping, but definitely a tingle. I've tried it with two different PSU's and still the same result. I moved the ground around trying to find a better spot, but still the same results. Is it a problem with my inverter, or should I have to ground it directly to the battery or frame?

    Thanks for any help.

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    Sounds like your ground isn't grounding. Try this - temporarily run a wire from the PSU to the negative terminal of the battery. See if it shocks you after that. If it doesn't, the problem was with your ground. If it does, check to see if the case itself is grounded properly.
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    I'll try the negative post thing, but my PSU is not inside a case. It doesn't need to be inside a case to be grounded, does it?

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    Quote Originally Posted by Khumpty
    Now whenever if the PSU is powered on and I'm touching any part of the truck body and the casing of the PSU at the same time, I get a slight shock.
    What does that mean, then?
    Quote Originally Posted by ghettocruzer View Post
    I was gung ho on building a PC [until] just recently. However, between my new phone having internet and GPS and all...and this kit...Im starting to have trouble justfiying it haha.
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    My man uses Levitra. Peoples's Avatar
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    no it doesnt need to be in a case to ground it
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    Quote:
    Originally Posted by Khumpty
    Now whenever if the PSU is powered on and I'm touching any part of the truck body and the casing of the PSU at the same time, I get a slight shock.


    What does that mean, then?
    By casing of the PSU I meant it's outer metal shell. When you said case I assumed you meant actual computer case. The computer is not in a case at all.

    Anyway, I started grounding the inverter directly to the -tive battery post. That seems to have solved the problem. Is it a good idea to also ground the PSU to the chassis?

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    Quote Originally Posted by Khumpty
    By casing of the PSU I meant it's outer metal shell. When you said case I assumed you meant actual computer case. The computer is not in a case at all.

    Anyway, I started grounding the inverter directly to the -tive battery post. That seems to have solved the problem. Is it a good idea to also ground the PSU to the chassis?
    Good to hear that fixed it.

    I've read that grounding the PSU to the chassis rather than the negative terminal on the battery (which would SEEM to be the best spot) is a good idea, but I'm fuzzy on exactly why that would be the case. I think it has something to do with the possibility of a differential in voltage between the negative battery termnal and the car chassis.

    What seems to be the common theme is to ground everything as close to the same point as you can.
    Quote Originally Posted by ghettocruzer View Post
    I was gung ho on building a PC [until] just recently. However, between my new phone having internet and GPS and all...and this kit...Im starting to have trouble justfiying it haha.
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    what part of the floor did you ground to? make sure its the actual floor pan itself (a huge piece of metal) and not something welded on like a bracket or worse something bolted onto the floor pan. spot welds and bolted on pieces have a lot of resistance.

    if you feel comfortable doing this, you might want to also consider adding a ground strap (as thick as possible) from the floor pan to the frame or to a solid ground in the engine compartment, although given that your truck is pretty new I don't think this should be necessary but you never know how tight the factory grounding is.

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    It was grounded to a sanded off piece of the floorpan.

    But just so I'm clear: I've grounded the inverter to the -tive post of the battery, and have NOT grounded the PSU at all. It is working fine, but should I still ground the PSU?

    BTW, the pics from my signature are no longer accurate. I don't have a case at all anymore. I can take some pictures if need be.

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