Hi All i need help, none of the solar installers or Generator Suppliers seems to be able to solve my problem.

I have tried with the Axpert MKS / MKS II / Axpert King and Recently the Axpert Infini VIII inverters all fully offgrid. No AC input from Eskom. only solar panels and Generator

They are connected to a bank of Pylontech us2000b Batteries and i have a 6kw Diesel Generator from Bundu Power connected with some kind of small AC filter fitted

I need the Generator to just charge or top up my Pylontech Batteries during rainy day`s but when the generator is started i can see the inverter detecting the AC input from the generator at 49-50hz 230-240v. 

As soon as the inverter starts to use the generator to charge batteries or to bypass (without any load in the inverter form AC Side) the generator will just stop within a few seconds (almost seems like it trips out. I then have to switch of the generator and back on the be able to start it up again.)

The only inverter that i have been able to use that works fine was a small 4kw Axpert 105v mppt inverter wich seems just fine with it but it is to small to use my generator to its full potential as i can only get at most 2500w out of it for charging the batteries. 

I have tried the APL and UPS setting on inverters. 

I have set the max Charge to 2A as a test 

Nothing help.

what could be wrong ?

 

What is the load that the Inverters are carrying just before they try to switch to generator? Maybe it's too high? and causes a surge that causes the genset to trip? Or maybe a electric motor  that is running somewhere? Fridge, freezer, Pool, water pump, UPS,  etc that then causes a huge surge when it tries to switch over?

Maybe try turning of circuits on the DB board - all them at first and see if the inverter will switch over to genset mains, if it then takes the load, power up each of the circuits and wait a few seconds between turning on each second for the genset to catch up to the load? One maybe able to idnetify whcih db board circuit it's related to?

Alternatively if it still trips the genset with no load, only the inverters, then check for Live Neutral hasn't been reversed when comign from the genset?

With my small 3.5Kva genset I have to turn come db circuits off, while running the genset as I have some items that seem to spike the load too high and then the genset will trip/stall. Very annoying. I suspect my 3 or 4 ups's that are in the house cause it, as they are switching ups's and probably cause a large spike as they switch back to mains etc. Not a problem when running on solar, but only when running on genset at night with load shedding

Also found that one should not really exceed about 50% -70 % of genset rating for long periods, more than 40 minutes as the genset can overheat and trip out. With your diesel version it will probably prefer at least a 50% load and max 75% load? to reduce the risk of glazing the cylinders, from too light a load, from what I understand.

 

 

On 2021/04/18 at 12:00 PM, Arandoza said:

What is the load that the Inverters are carrying just before they try to switch to generator? Maybe it's too high? and causes a surge that causes the genset to trip? Or maybe a electric motor  that is running somewhere? Fridge, freezer, Pool, water pump, UPS,  etc that then causes a huge surge when it tries to switch over?

Maybe try turning of circuits on the DB board - all them at first and see if the inverter will switch over to genset mains, if it then takes the load, power up each of the circuits and wait a few seconds between turning on each second for the genset to catch up to the load? One maybe able to idnetify whcih db board circuit it's related to?

Alternatively if it still trips the genset with no load, only the inverters, then check for Live Neutral hasn't been reversed when comign from the genset?

With my small 3.5Kva genset I have to turn come db circuits off, while running the genset as I have some items that seem to spike the load too high and then the genset will trip/stall. Very annoying. I suspect my 3 or 4 ups's that are in the house cause it, as they are switching ups's and probably cause a large spike as they switch back to mains etc. Not a problem when running on solar, but only when running on genset at night with load shedding

Also found that one should not really exceed about 50% -70 % of genset rating for long periods, more than 40 minutes as the genset can overheat and trip out. With your diesel version it will probably prefer at least a 50% load and max 75% load? to reduce the risk of glazing the cylinders, from too light a load, from what I understand.

 

 

ok my generator is not connected to any load, nou ac cable connected to output side of my inverter. I basically have the invert connected to the generator and then to the batteries.

the generator wil start up and takes maybe 5 seconds then it kicks off?

8 hours ago, Leonvd1983 said:

the generator wil start up and takes maybe 5 seconds then it kicks off?

I believe that the inverter will "watch" the AC-in for a few seconds, then if it passes some tests, it will connect the inverter output to the generator and gradually increase the charging power. So it seems that it's the instant that the inverter connects (perhaps out of phase?) or when the current ramps up.

When you start or connect the generator, does the AC-in icon flash for a while, then perhaps go on solid, then go away after the generator stalls? If so, at what stage does the generator stop? 

the ac icon does flash for maybe 2 seconds then go stable then i hear the click from relay i suppose then the generator stalls out.

2 hours ago, Leonvd1983 said:

the ac icon does flash for maybe 2 seconds then go stable then i hear the click from relay i suppose then the generator stalls out.

That sounds like a generator problem then.

Have you tried putting temporary load on the generator before connecting to the inverter? After connecting to the inverter, you could then take the temporary load off. I usually suggest around a 200 W load, but since you have such a large generator, perhaps more like 500 W, give or take several hundred watts. Just so that the generator doesn't go from zero load, where it might be in some sort of low fuel condition, to non-zero power when the inverter is carefully watching its frequency.

How are you starting the generator, manually or with an auto start? If it's auto start is the auto start being disactivated?

Does the generator have a start control module with a display? Often these show the reason for shutdown.

Is the generator stable (engine sound steady)? What about in the few seconds when it connects before stopping, do you note any change in the sound?

Can you measure the output voltage (and if possible frequency) of the generator and see if it drops when the inverter transfers. Some generators will shut down if they see the voltage and/or frequency dropping out of tolerance. If there is a control panel on the generator then these parameters can usually be modified.