question

hi, have you some details about your AC load equipments?? if the converter have fuses inside (as i think), they can be blowed by an overload (you need to open it to confirm this)..

also, if no short there, you can disconnect the AC wires output and confirm the power consumption with any cheap watts meter using a domestic ac cable extension.. check the load watts power (the peak/max) for the rush power (some equipments do a rush/start current 3-4 times of the power writed on it)..

the inverter stopped working without any real load on the AC OUT. There are 4 120v gfci outlets that are meant to be powered by Multiplus AC OUT, each protected with a 15 Amp breaker. However there is nothing plugged into 3 of those outlets. The 4th outlet has induction cooktop (I think rated for 1500 W) plugged in, but it was off when the inverter stopped working.

Maciek, though we went over this by phone I thought it good to write a little list of things-to-try.

• Disconnect the GX at the inverter (unplug) and try starting the inverter just from the rocker-switch in the front.
• Disconnect (just temporarily take the wires loose) the AC wiring from the inverter, and try starting it.
• Measure the DC Voltage at the inverter itself, with the inverter switched on, to make sure it's it's not a bad connection that drops the Voltage to the inverter as soon as there is some load (I've seen this happen twice now).

When I have some time I'll open up a Multiplus here to have a look. I seem to recall there is a fuse inside the units as well (as a measure of last resort), but am not sure.

-Rob-

Maciek, can you please post a picture of the unit after you take the front-panel off. Please make it so the DIP-switches are visible (or post a separate picture showing those in addition).

I've opened up a Multiplus 3000 here, but no fuse is visible. So either these don't have a last-resort fuse in the battery line, or it's hidden somewhere out-of-sight (my guess is there is none).

-Rob-

Rob, thx your replies. Here is the info you requested plus some additional develoments:

1. with GX disconnected (i.e. unlpugged ethernet cable from the inverter itslef) - there was no change, still the inverter wasn't turning on

2. I didn't yet disconnect AC wiring from the inverter and would like to leave it as last resort. There is not much space there and it took me quite some time to get clean connections when installing the inverter, especially for the AWG 6 wires connected to AC OUT 1

3. DC in voltage at the terminals of inverter were at 13.74 V when I measured this morning.

4. Pictures are attached. All 8 dip switches are in the off position

5. Yesterday I went to a local distributor of Victron and they connected PC with MK3/USB to the inverter. As soon as they did that (without changing any settings), the 'Inverter ON' LED lit up and 120V appeared at the AC OUT 1 terminals. They mentioned there may be a need to adjust settings of the inverter thru the app to avoid the inverter from going into this locked up state, but no settings were changed. I picked up the MK3 USB from them and could adjust the settings (but will need some guidance which ones)

6. I noticed 2 things that suprise me a bit about the inverter and how it works in my setup. I'd appreciate if you can clarify if this is normal/expected behaviour:

a) with the inverter off (i.e. toggle switch on the inverter in the middle position), there is continuity between line and neutral terminals on the AC OUT-1. Would you be able to check on your unit if you see the same?

b) when disconnect the battery bank (there is a kill switch between batteries and positive bus bar), for a minute or two there is still some residual voltage in the system and that voltage drops over those 2 minutes to zero. This started when I connected Multiplus to the setup - is this normal?

7. I'm also attaching diagram of my setup.

Thanks,

Maciek

Maciek, Victron suggests the Multiplus is switched off (from the front switch) when the MK3 is connected to it. Best I know you already tried this, but the suggestion is to switch the unit on/off with the front switch, or try connecting with VE Configure and use the virtual switch to switch on/off.

Unfortunately I don't have a setup here that can duplicate this, so my guidance is limited. Since the inverter works fine (with the MK3 connected) it is not likely there's anything wrong with the unit itself. I'll provide Victron with your phone number, so someone may call to try and talk you trough a few things (to try).

-Rob-

Rob,

Thanks again for looking into the issue and putting me in contact with Victorn SME. For the past week I've been keeping an eye on the inverter, with and without the GX remote, turned it on and off a few times and I don't see the problem reappear. Since the issue seems to have gone away lets consider this resolved.

Regards,

Maciek