Ground Wire from Inverter getting hot, I have a few ideas but looking for advice

[Iceni John]

I've found lots of clamp-on DC ammeters that read up to about 400 amps, but that may not be enough to read starting current for a big diesel.   Craftsman has (had?) their so-called Professional series 800 amp AC and DC ammeter, model 73756, but its actually an Extech EX730 with the Craftsman name on it.   When I bought mine it was missing its thermocouple probe, so Sears had Extech send me a replacement!   I don't know if it's still available, but I paid less than $100 for mine.   I haven't had a chance yet to measure any high-amp DC currents with it, but it seems like a decent inexpensive meter for occasional use.   Obviously a Fluke would be nice, but for the little I'll ever use mine I'm happy with it.

John

[Gordie Allen]

I noticed in your diagram you have your batteries linked by a daisy chain, Is your inverter also a charger? If so, I read a number articles last year that recommended all cables be the same length with all the positive cables going to a common post and all the negative cables doing the same. I have four 250ah 8D deep cycle gel cells. I made a large bus bar with two 3/16" x 1.25" x 10" copper bars screwed to a 4" x 6" x 12" block of wood that all the cables bolt to. From there I have one positive and one negative going to the inverter/charger. All are 0000 cables of equal length. The bus bar is enclosed!  The point of the articles was that each battery further down the chain gets a little less voltage and the reverse is true when pulling energy from the batteries, shortening the life of the batteries. I have a 400 amp fuse between the batteries and the inverter. I'm not a professional electrician, but I thought it made sense assuming that the batteries closest to the charger don't modulate the voltage for the next battery down the line. Just thought I'd throw this out since I haven't posted anything in a year or so.

[bevans6]

I think his main problem, aside from the possible bad crimp, is he's pulling a big overload when he tries to start that old AC unit.  Dropping output voltage from the inverter to 70 volts indicates a massive overload.  I am surprised the inverter is still working, I had an AIM inverter that ate it's output MOSFETS for lunch when I had an over-current situation.  No warranty, no possible repair, all they would offer was swap the unit for full retail.  I bought the Magnum.

[neoneddy]

re:bevans6 , the smoking / hot end was happening when the AC was running fine, normal current loads.   Aims LCD would show 50-60% usage of the 3000 watt capacity.

Going to pickup the new AC Today will report back on the AC / Inverter thread.

[windtrader]

I had an AIM inverter that ate it's output MOSFETS for lunch when I had an over-current situation.

All this overloading of inverters is making me poop my pants. Don't even the most basic inverters have quick acting fuses/breakers to prevent damage when feed too much of a load?

[Jon]

I'm guessing the folks intent on running A/Cs through inverters are not concerned about the long term damage, but instead are looking for ways to do what even the inverter manufacturers cannot recommend.

Regardless of the inverter rating the newer styles are not intended for the handling of the starting current.

[Oonrahnjay]

...   Aims LCD would show 50-60% usage ...

     Yeah, AIMS inverter.  You're not the first ...

[neoneddy]

Sounds like we nee to do an Inverter round up.  Have some litmus tests  we cna all run and measure.

Eventually I hope to  go full Victron

[Oonrahnjay]

Sounds like we nee to do an Inverter round up.  Have some litmus tests  we cna all run and measure.

Eventually I hope to  go full Victron

     Yeah, me too (although as savvy as the Technomadia folks are, they have struggled a bit because, as they put it, Victron is more oriented toward home/off-grid systems and not mobile/vehicle/boat systems and they've had some issues with not-optomized-for-vehicle problems that Victron didn't seem to care about.  Maybe Victron's customer support has gotten better.)

[neoneddy]

First to finalize my initial issue.

I was testing my new Mach 3 Plus AC setup and noticed my battery was draining, even with the bus running  my bank read 23-24v .. not good. (under 90 or so amps of load).  I checked the coach battery / alternator output.. it was good at 28-29 ... the house battery bank ground was completely hosed.

I crimped a new cable and grounded to the frame from the  inverter / battery common ground point.  I think I'll add a secondary as a backup, similar to how home electrical systems have 2 grounds, goof enough for me.

Additionally I use a small butane torch, flux and solder to make an even stronger connection.   I do realize that if the terminal gets hot enough like before the solder would melt, but it only got that hot because of a poor crimp connection.  This is crimped and soldered now.  Cool as can be.


Re: Technomadia / Victron - Do you know what threads they talked about their troubles?  I followed their youtube channel and didn't catch much negatives.  Chief's Prevost youtube also used Victron, kinda figured it was the gold standard.     What I liked most is how it all works together with the Color Control LCD panel and it shows power coming from batteries , solar and shore or generator power.   Even shows what you used, etc.

[windtrader]

What I liked most is how it all works together with the Color Control LCD panel and it shows power coming from batteries , solar and shore or generator power.

I believe most MPPT charge controllers have advanced features such as this; I do not believe it is unique to Victron units.

[Oonrahnjay]

... Re: Technomadia / Victron - Do you know what threads they talked about their troubles?  I followed their youtube channel and didn't catch much negatives.  Chief's Prevost youtube also used Victron, kinda figured it was the gold standard.     What I liked most is how it all works together with the Color Control LCD panel and it shows power coming from batteries , solar and shore or generator power.   Even shows what you used, etc. 

      ISTR it was the "solar" postings.  Don't get me wrong, they talk about a LOT that's right with the Victron, but there were a *few* aspects.  And I seem to remember that those posts were from about 2013, only a year or so into their lithium experiment.  And yeah, the color panel display is total drool candy.  (BTW, they've bought a boat now too -- I guess they wanted to spread their money pits out!!)

[neoneddy]

In this video I show my new ground location and the grid tie inverter in action.

https://youtu.be/11c1enwgk6g


Sent from my iPhone using Tapatalk