Sine Wave Inverter Anomaly

brulaz wrote:
Could it be your Surge Guard doing this?

SoundGuy wrote:
I wasn't going to bother since I've now established that my inverter installation is working just fine but your question and this discussion have peaked my interest so when I get time later I'll unplug my Surge Guard and see if the results are the same without it. One the advantages of owing a trailer short enough to fit on the driveway! :B

brulaz wrote:
And how are you testing that this auto-bonding is happening?

Obviously the first indication that bonding is occurring is when the polarity tester no longer shows an error. I'm still not clear why this tester shows an "open ground" error when in fact it's seeing a "floating neutral" but confirmation that bonding has occurred is easy ... just measure with a DVM and if the voltage reading between hot and neutral is the same between hot and ground then obviously neutral and ground have been bonded.

I did my aforementioned test and as I expected the trailer's electrical system behaved exactly the same whether my Surge Guard was in the circuit or removed entirely. The inverter's output is definitely floating but shows up on the polarity tester as an "open ground", which it isn't :h ... as soon as the main service cable is plugged in (with the converter turned completely off, including it's master breaker) that so-called "open ground" error goes away, with or without the Surge Guard in the system. Everything works as it should, voltage measurements are exactly what they should be where they should be, and there are no errant voltages where they shouldn't be ... my guess is your new EMS will behave the same.