Powering up Inverter without ground

phatchink · 02-28-2005, 04:09 PM

becuase my inverter was producing a high pitched whining noice some of you guys suggested that it might be becauwse my ground was hooked onto my car battery's negative terminal. However, I unhooked it today and found that the inverter still powers up for some reason, can anyone explain to me why that is? the inverter works without grounding it!?!?!??

Also I've tried grounding it near the spare tire, but the whining noise is still there, I'm not sure if thats a good ground. I used a DMM to check but not sure if I did it right, can someone tell me how I'd go about checking?

phatchink · 03-01-2005, 02:36 AM

woops wrong seciotn

xdjxklusivex · 03-01-2005, 02:42 AM

:-P ill answer even though its in the wrong section...i ran mine through a fuse you need a inverter with a remote power on options (have not seen one but i think they make it) have fun! POST RESPONSIBLY LOL

phatchink · 03-01-2005, 04:27 PM

Quote: Originally Posted by xdjxklusivex

:-P ill answer even though its in the wrong section...i ran mine through a fuse you need a inverter with a remote power on options (have not seen one but i think they make it) have fun! POST RESPONSIBLY LOL

nono maybe your're not getting my question, i wired up to the front of the car, it does power up when I pressed the button, but it powers up WITHOUT the ground connected, why?

can admin please move this to the power supply section?

WebDog · 03-01-2005, 04:43 PM

do your not hooking it up to the car metal? is the inverter sitting on bare metal?

wizardPC · 03-01-2005, 05:00 PM

Quote: Originally Posted by phatchink

...but it powers up WITHOUT the ground connected, why?

Because it IS connected. Did you bolt it down?

'cause that might ground it

turbocad6 · 03-01-2005, 05:57 PM

If it's grounding through the case this may be part of your problem with the noise. You might want to isolate the inverter( mount on plywood or ?) & then see if you have the noise problem with the cable grounded......dual ground plain could cause noise.........

Adam432823 · 03-01-2005, 06:40 PM

Bear in mind that the inverter has no way to create an earth ground, so the ground wire on the 110 socket goes the negative terminal on the inverter (which usually goes to the battery). There's really not much more to it. The ground on the 110 socket is connected to the chassis of whatever you have plugged into the inverter. If, for some reason, that device is touching bare metal, then there's your ground. You need to make sure that you only have one grounding point (the negative lead on the inverter). Make sure that ALL your devices (including the inverter) are not grounded by way of the chassis.

It seems possible, though kind of unlikely, that maybe whatever you have plugged into the inverter is grounded incorrectly. For instance, you have a PC hooked into the inverter. The audio out socket is grounded to the chassis and then the amplifier that you have it connected to is grounding the audio in connector as well. I've heard of this situation causing ground loops in audio equipment before. Only one end of your audio cable should be grounded. In most applications, the head unit grounds the interconnect cable. But if your amp is grounding it and so is the pc, then that could be closing your circuit. This would put a lot of amperage through your signal wires, and I'd imagine they'd get hot or melt if that was the case. And naturally induce a lot of noise.

phatchink · 03-01-2005, 11:11 PM

Well The inverter is currently bolted on the computer case which is bolted in the trunk Maybe THATS grounding it!!! HUM! very interesting, I never thought about that I'm such an idiot

i'll try bolting it onto something else tmr

WebDog · 03-01-2005, 11:35 PM

Quote: Originally Posted by phatchink

Well The inverter is currently bolted on the computer case which is bolted in the trunk Maybe THATS grounding it!!! HUM! very interesting, I never thought about that I'm such an idiot

i'll try bolting it onto something else tmr

just try setting it on carpet dont worry about bolting it down yet, if that works better bolt a peice of wood to the car and then bolt inverter to the wood.

ATXaccord05 · 03-01-2005, 11:47 PM

This might be the same problem I am having, I'm grounding my inverter through my chassis. Just for future knowledge, why would grounding through the chassis make noise?

Adam432823 · 03-03-2005, 06:55 PM

Its the dreaded ground loop. Anytime you have multiple paths back to ground you're just asking for inducted noise. Your best bet: make sure you have all your grounds tied to the same spot. Usually a single bolt onto a structural part of the car.

phatchink · 03-04-2005, 01:54 PM

i tried grounding it through the battery and chasis, both produces a high pitched noise...

wizardPC · 03-04-2005, 02:32 PM

ok, this is gonna sound really wierd, but I think I know what is going on.

Your screen (or some other powered device) isnt grounded properly. It also may be the reason your inverter comes on when there is "no ground attached."

Your inverter is grounding through your screen. I kid you not, I remembered last night that I had a similar experience. The ground is coming through the screen's ground, over the VGA cable, through the motherboard to the power supply and out to the inverter. I'll bet that your inverter doesnt come on if you unplug the computer and disconnect the ground, as opposed to just disconnecting the ground

WebDog · 03-05-2005, 11:12 AM

yea. and then when you get the system up its best to take power+ gnd from pc power supply.