Installing a power inverter??

[Dennis Steele]

I want to install my 750w power inverter in the box of my truck.

I measured and found that I need aprox. 22 feet of cable to where I want to install it and have 6 gauge cable to do it.

My question is, can I (should I) ground the negative to the frame, or run it all the way back to the negative post on the battery.

[AQUAJOE]

It needs to go to the frame.

[Giant_Jackpot]

It should be no problem to ground right to the frame. Make sure your negative connection from the battery to the frame is good and you are set.

[H20fowlr]

Run it to the battery. If you get any leakage it will travel through the frame and into the engine. Won't be noticebale until you start wearing out bearings or interfereing with sensitive electronics like fuel systems or electronic boards.

[McGurk]

I Agree with Giant Jackpot; Use the shortest possible run of Ground wire (the same size as your positive lead, can even be the excess of the same wire wrapped in black tape for identification) to the frame (less than 18") and grind the paint off about the size of a nickel and use a good connector. Likewise make sure that the battery ground lead has a good connection to the frame under the hood. Everything else is grounded through the frame, big or small, including your starter motor and alternator.

Good Luck! McGurk

[LMITOUT]

Also make sure to put an inline fuse not more than 18" from the battery. The reason for this is if you had the fuse near the inverter (or any electrical load) and got into an accident where the power wire was severed, it could spark and ignite any flammable liquid or gas.

For the ground do as mentioned above, making sure to grind any coating off of your ground point. A lot of newer vehicles have a coated frame. It's also a good idea to use a star washer which will dig into the metal grounding spot to help your connection as well.

Good Luck!

[hitthebricks]

I hooked mine to the battry and maybe thats why when I installed a 75 watt inverter in my truck so I could run a printer from it but it would not even start the printer. I then tried a 400 watt inverter and that didn't work either, so I installed a 800 watt inverter, same result. Does anyone know why? The printer only needs 40 watts to operate and I've tried everything from light bulbs to a impact wrench and they all work.

[JollyT]

The waveform may be too rough to run electronics. That would be my guess.

[AQUAJOE]

I was told by Interstate Batteries and (DAS)dealer automotive services never go directly to the battery if it can be avoided for accesories.

Dennis call either one of them and they can explain what to do and why.

[Giant_Jackpot]

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Run it to the battery. If you get any leakage it will travel through the frame and into the engine. Won't be noticebale until you start wearing out bearings or interfereing with sensitive electronics like fuel systems or electronic boards.

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If this is true, then we all better go check our blinker fluid and muffler bearings……..

[Giant_Jackpot]

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I was told by Interstate Batteries and (DAS)dealer automotive services never go directly to the battery if it can be avoided for accesories.

Dennis call either one of them and they can explain what to do and why.

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Joe,

I gotta believe what they were talking about here was to make sure there was a fuse in the circuit as mentioned by others posting here. In one way shape or form, all of the accessories on a car are connected to the battery.

[H20fowlr]

Very Funny. As the former applications manager of the worlds second largest generator manufacture i have witnessed numerous main bearing failures on the engine and the alternator bearings due to poor grounding. The circulating currents travel through bearings and create heat. Go to one of the bearing school classes held by NTN, FAG or others and they show pictures of this type of failure.

So muffler bearings, blinker fluid, arfalator valves are funny, but not as expensive as improperly grounding and the real impact it can have on your vehicle.

[Giant_Jackpot]

I have no background to dispute what you say but I did spend a number of years in the automotive repair business and I have never heard of this happening. Personally I would not worry about it and as you say it is from improper grounding. So if Dennis follows the good advice given so far for the grounding portion of his project, he is not going to have a problem. By the way, my blinker fluid was low this morning, good thing I checked!

[H20fowlr]

Giant I like your sense of humor. Your correct if done right no problems. As far as the automotive industry experience, I would venture you did not many issues with AC electricity, unless you are in the RV industry. It is different than DC.

Our Sister Comapany is Huge in in the RV market and uses our product in RV's and use inverters. I will ask some of my peers their recommendations, and I will post.(Due to travel schedule it probabaly won't be until after next week.) They happen to make those Green Generators. Hint hint.

Good luck and I'm off to greas my muffler bearings on the snowblower before all this snow falls. BTW where can i get the Blinker fluid? Is it next to the Arfalator valves?

H20fowlr

[nytelyter]

just remember you can use a left handed monkey wrench to both remove the cap on the blinker fluid resivour. and replace those stuck muffler bearings. it is nice to have one tool instead of two speciality tools. although i like speciality tools hanging on my tool board they just look cool . .... paul

[waskawood]

Electricity takes the path of least resistance. It makes no difference if it is direct current or alternating current. If there are any bad "connections" in the frame, it is very possible that the return current could travel through a bearing or another device to find its way back to battery. I would mount the inverter as close to the battery as possible. I think the draw back to going directly to the battery with an inline fuse is that if you forget to shut the inverter off it will darw the battery down where as if you wired it to a relay powered by the ignition switch the inverter would shut off with the key.

[AQUAJOE]

Waska exactly. That is what I was trying to say about not going direct to the battery. Without that relay you are asking for trouble.

[McGurk]

That would have to be a serious relay for these big inverters, aka a solenoid(sp?). Most relays that I know about are about a 30 amp rating, anything larger than that would fry the relays. It could be done with a solenoid, though. Same thing as the inline fuse: keep it within 18" of the battery. Good Luck, McGurk

[Dennis Steele]

Thanks guys for the advice and the chuckles.

However, I am curious why it would be a bad idea to run back to the negative?

Maybee, I'll call Interstate.

[Jeremy airjer W]

6 gauge might be a little small. 4 gauge is recommended for 14 to 24 feet. This thing will be pulling around 75 amps from the battery while it is max continuous wattage of 750 watts. (ten percent of the wattage being used)

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I am curious why it would be a bad idea to run back to the negative?

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I'm curious about that myself!

[Giant_Jackpot]

Dennis,

From my point of view the only reason I suggested going to the frame would be to save the cost of the wire. There would be no problem running both positive and negative to the battery. Sorry if I caused any confusion on that one. As far as using relays and such I personally would not do it that way just to keep things simple. If you forget to unplug something from the inverter and you have a dead battery as a result, you probably won’t do it again!

And for the bearing debate? I got way too many other things to worry about in life than if some stray current is going to toast a bearing. Connect your inverter to the battery and use it (sort of the “set it and forget it” principle).

I hope this helps.