Inverter Mystery..

I understand why you said it but it isn't the case, as NM said, it was grounded through the case. The circuit board itself has a ground plane designed to limit RF harmonics and to allow the discrete devices to function properly, the other purpose is to provide a shield for the transformer in many of these designs. When you said ground plane, it makes it sound like there is an actual ground plane and not a ground buss system.

The failure was obvious as also mentioned by NM that the board carried the current and didn't have a way to get it any other way. I disagree with using the frame, the problem is that the frame ground and the ground to the battery serve two different purposes in a properly designed inverter. But also in one of these cheap ones too, so I recommend using the frame ground to ground the 110 outlet, the battery negative to use to power the unit because of the current it will need to function will cause the voltage to drop in many cases if the frame is used.

 

Not really,, if that was the case of voltage drop then all electronics in the truck would also have this issue.. Car/truck frames have been used as a ground plane for many decades...

 

I don't agree

You need to use the right term, it is just ground. Not a ground plane.

The ground plane is used for a few things, one is in RF applications, another is circuit board design.

You can use the word ground, common ground or Ground Bar or Ground Buss/bus, because those are all common ground connections.

OK why not to use frame connections, because it inserts another point of voltage drop. We are not talking about using a system that consumes 20 amps but up to 200 amps and the voltage drop with another point will cause one of a few problems, one is brown out conditions - some call it overload when the buzzer goes off but in many cases it is the low voltage on the input of the inverter. Another one is a destruction of the switching devices trying to adjust the frequency to compensate the system with the lower input voltage and there are a couple others that are hard to explain.

The best way to install any high current device, like an inverter or a lift gate pump is to have direct connections to the batteries because of the amount of current that is needed to run those devices.

 

Not true... Electrically any point on the frame is the same as the battery terminal. Just make sure you have metal to metal contact, scraping off any paint. If you don't then you may draw a higher current.

So if the starter draws high amps to turn over, why is it using the truck frame as the ground? And the starter draws more than an invertor..

Connecting a heavy-load power inverter

For powering loads of over 150 watts, you should connect the inverter directly to your car battery. This requires a 4-gauge power cable and draws power directly from the positive battery terminal. An in-line fuse or circuit breaker (typically 80 amp) installed near the battery is a must. Without one, an accidental short circuit could pose a fire hazard and damage your inverter, not to mention your car itself.

Power rings will simplify the connection of the cables to the power source. Unscrew the nut that secures the positive (+) battery terminal to the battery post, slip the power lead terminal over the bolt that secures the battery terminal to the battery post and replace the nut. Do not attach the power lead terminal directly to the battery post.

How and where to ground your inverter
The ground wire should be the same gauge as the power cable and must make direct contact with bare metal of the car or the negative battery terminal.

Look for an existing bolt or screw that makes contact with the car body near the inverter. Remove the bolt or screw, and scrape away any paint or grime. A star washer will help your ground wire maintain solid contact with the car body. Crimp or solder a ring terminal onto the end of the ground wire, slip it underneath the washer, and replace the bolt or screw.

If you can't find a convenient ground screw or bolt, drill a hole for one. Be careful not to drill into the gas tank or a gas or brake line.

 

OK what ever,

I'm offering advice based on my education and my experience.

Not an issue for me, I've got my inverters in my trucks all working as I posted, NO issues. Those who installed them on the used trucks I bought all had issues which went away after they were changed.

Starters have three ground contracts, direct cable, secondary cabling and metal to metal contact by the way.

 

I am quite aware of how a starter is grounded. Based upon 20 years of electronic schooling and experience using the frame of the truck or car to run your negative wiring has no secondary issues if installed correctly. Most will just bolt or screw it to the frame without proper cleaning to get metal to metal contact. The systems I worked on mostly were on tanks, amtraks, jeeps, trucks, and towed. So, I dealt with the grounding of many types of electronics

 

Sorry. 20years you did grounding wrong. You was trained to do so. It's cheaper for manufacturer and destroys frame what is good for manufacturer as well. Before arguing look at aircraft electrical systems or marine.

 

Sorry 20 years ground done right... amazing how all the electronics worth millions of dollars worked. and boats use a ground plane.. I own boats also..

So, what you are saying is that all those highly qualified electrical engineers were all wrong and you were right...