Hi All. New to the forum. An issue has arisen where the inverter is inverting while in charger only mode. Set up is a couple months old and has been running great until now. I plugged into shore today so that I could turn on a space heater and the inverter, which is usually in charger only mode (physical switch set to II and Cerbo GX set to Charger Only). At first the inverter wasn’t detecting shore power (the same power outlet I have plugged into before). A multimeter was showing 118v on the inverter input terminals.
I did a software update and reboot. It now detects the shore power, but is inverting when in charger only mode (again, physical switch set to II and Cerbo GX set to Charger Only). When I unplug the heater, it stops inverting. Plug the heater back in and starts up again. It’s never done that before. The heater draw (and only draw) is about 10A on the 15A power source, so it should not be trying to assist.
There’s nothing to indicate, other than sound, that it is inverting. System says it’s bulk charging or in storage mode. Battery is 100%. What am I missing?
Funny you should say that i have also noticed my multiplus 11 3000 inverts when in charge mode only. I have to go back to my victron installers soon so will ask about it.
“Charge Only” mode still allows passthrough when the unit is connected to shore power - that’s not inverted power, it’s just passed-through power.
When you have your unit in “Charger Only” mode and connected to AC input, it passes through AC input and charges the batteries, then when the AC input is disconnected, the MultiPlus should shut off rather than switching to provide inverted power.
Appreciate the insight Justin, but this part I understand. Prior to having the issue (and remedy) of not detecting the shore power, the inverter was quiet when passing AC power through. It is not quiet now and makes the same, not subtle, noise as when it is on Inverter mode. I can’t see the transfer relays making that much noise.
Ah, okay, noise could be a few different things, but doesn’t itself indicate inverting. These units cannot invert and charge at the same time, so if you are charging then you’re definitely not inverting.
I seem to recall a few FW versions back , late last year maybe, there was a FW version for Multis that was supposed to help with resonant noise from the transformer, not totally sure if it worked since I never had much of an issue myself to be able to compare, but possibly worth some digging into since you’ve narrowed the issue down to a noise problem rather than a (per se) functionality problem!
I will dig into that some more. Thanks for the direction. I will also test to see if it is actually charging. The only reason I wonder if it is inverting is that the noise only occurs when plugging in an AC load. Noise level is a function of load. More load, more noise.
