Hi everyone, I am new to the forum, but have been following

Does anyone know what this means on the slave unit of 2 X Axpert 5KVA in parallel?

I am concerned that

1. the slave inverter is not showing the "Load" that normally appears under the muted speaker sign,
2. also the occasional strange message "nE" it is showing in the top middle of the screen.
3. Additionally this slave does not seem to take any physical load (If I isolate the Master,the power to the house drops), which may be related to what is indicated here.

Background:

I have connected the 2 5kva Axperts in parallel, according to the  documentation on the sites.

1. In non-Parallel mode, each Inverter individually takes the load when supplying my house, if the other is switched off/isolated. Then all indicators, and screens are normal, showing % load etc.
2. In Parallel mode this is shown on the slave unit, the "nE" appears every now and then, and it is not showing the load icon/symbols under the muted buzzer sign. The slave unit alos does not seem to take any load, when I isolate the Master's load, the power to the house disappears.

I have configured the inverters to run in Parallel on Program 28, while they are in standby mode and this happens on the slave inverter. 

Does anyone have an idea?

 

also the occasional strange message "nE" it is showing in the top middle of the screen.

This means it's not a master and not a slave; it's a "new" machine, as in new to the party, don't know where to fit in.

 

the slave inverter is not showing the "Load" that normally appears under the muted speaker sign,

So it's not happy with the environment, and is not turning on its "load" relay.

* Does the master show HS (or MS if patched)?

* Does the slave show SL when not showing NE?

* Did you confirm that the parallel mode "stuck" after attempting to make the change?

* Did you have the inverter switch off when changing setting 28?

@Coulomb Super thanks for the quick response.

 

* Did you have the inverter switch off when changing setting 28?

Yes, On both machines, I was only able to get into setting 28 with the inverter switched off by the on/off switch(Bottom-right under units).

 

* Does the master show HS (or MS if patched)?

* Does the slave show SL when not showing NE?

See Below for the Master and the slave, both switched on now. (With LOADSHEDDING no surprise there🤪)

 

 

 

* Did you confirm that the parallel mode "stuck" after attempting to make the change?

 

I believe so, if I interpret the documentation correctly, Master is showing "HS" and Slave is showing "SL" permanently, unless of course I missed something important?

Else is there some steps I can take to check?

 

Regards, 

Fishey

 

 

The intermittent NE on the slave is a bit of a worry; it might indicate aging optos in the parallel board(s). But it could also be unreliable CAN bus wiring.

I wonder if the current sharing cables might be playing up. They're the twisted pair wires, as opposed to the VGA-like cables (for old timers who remember VGA and even EGA video adapters and their distinctive cables).

Has this been working and failed recently, or are these inverters newly paralleled?

Hi @Coulomb

I finally got the new inverter taking load. (Still flashing the "nE" occasionally)

Your mentioning the fact that the second inverter might be thinking it is "New" up had me thinking, so I powered down everything, isolated everything so nothing was active, and gave it a bit of a rest. Then when I brought the installation up by connecting the batteries first, and going through the parallelization from first steps, both are now taking load. 

 

The intermittent NE on the slave is a bit of a worry; it might indicate aging optos in the parallel board(s). But it could also be unreliable CAN bus wiring.

I wonder if the current sharing cables might be playing up. They're the twisted pair wires, as opposed to the VGA-like cables (for old timers who remember VGA and even EGA video adapters and their distinctive cables).

Has this been working and failed recently, or are these inverters newly paralleled?

This is a new installation of a couple of inverters I obtained second-hand. This is the first time I got them behaving as a parallel set. 

I think I need to do a bit of basic electrical stuff now, like cleaning the current sharing pins on the comms board, using a multimeter and checking for intermittency on the the wires. 

Thanks for the help mate. 

Best regards

Fishey

 

This is the first time I got them behaving as a parallel set.

Are the paralleling boards new or old?

 

Are the paralleling boards new or old?

Both are old. Came with the inverters, already installed. The length of the VGA-like cables are also not the same, the one is 3 times the other's length, not sure if that is relevant.

 

The length of the VGA-like cables are also not the same, the one is 3 times the other's length,

Oh. As far as I know, that means that they are non-standard; I've never seen an option for a longer cable. So it's possible that this cable is not intended for carrying CAN bus signals, but the standard cables are. I would not think that say 4 metres would be too long, but I guess it's possible. Can you buy a shorter actual VGA cable from a local electronics store? I have no idea if they are actually VGA cables or just look similar.

Consider swapping the cables to see if the problem seems to change.

Another option, if things get desperate, would be to buy one paralleling kit. That will have one standard cable, and a new paralleling board to swap with one of your existing ones.

If you're handy with electronics, you could also try replacing the opto couplers in at least one of the boards. They do lose their current transfer ratio over time, and they seem to be a little marginal to start with.

Thanks Coulomb,

Yep, I am handy with a soldering iron, and am ex military microwave techie.

I will give it go. Thanks for all your help.