Power Jack 6000WLF 24Volt Inverter

[colmaudson]

The inverter has a 25.5 volt battery feeding it and shuts down on no load after 5 mins. With an electric motor 2.5amps it will shut down after approx 25mins. Why? Any suggestions?  Where can I access full information from Oztules regarding information of the extra reduction choke that was made and the diagram regarding connection. Thank you

[oztules]

Hi,
The choke is a simple ferrite ( not metal) e-core. It has 3.5 turns of heavy wire. It is an E65 core ( ebay?) It is simply connected in series with either of the wires going from the small heat sinks to the transformer.. it is in series with either lead...... very simple really.

The shut down is probably the mppt controller upsetting the unit. This can be fixed by bypassing a resistor on the board....
First ascertain this is the problem by running the motor without the mppt connected... if it runs indefinitely, then thats the problem.

It is sensing the high voltage currents from the mppt. A meter will not show them, and will read 26-27v.... but an oscilloscope will show that there are very high current pulses that average out against the low impedance of the battery as the 26v you see.
It usually happens when there is plenty of sun, and fuller batteries... then the pules will be added up by the chip, and it spits the dummy as high battery voltage fault.

I have not been successful in damping this ( haven't tried very hard either ), I simply put a 5v6 zenner across the" cut if low resistor" (R14) you will see near the chip.... this will stop the unit seeing a high voltage battery problem..... and your mppt controller will look after the battery for that situation anyway.

Note, it will also mess up the charging voltage of the unit, and it won't know when to stop charging.... but I don't recommend using the charging function as a rule, it can destroy the unit without modification anyway, as the software was written for lossy e core transformers with high leakage. when it is cut off from the grid or generator, the sine wave reverts to 50 hz, and can catch the transformer in the wrong magnetic circumstance ( near zero crossing is bad). In the lossy transformer, this transient will be swamped buy the fets, ...... but with torroids, they will likely kill the fets with the massive inrush currents. If you do the transformer mods to the inspire units, this is exacerbated further.... they are very tight, and have very low leakage, so the kick back will almost always kill the fets... and the drivers follow.... some 60 times the magnetising currents for a few cycles.

I have not found any load that annoys the unit as an inverter.. they are very tough in that regard.


john

[steve3]

Hi Oztules (John) Many thanks for all your help in the past with my PJ Lf 8000w inverter, all still seems to be working fine thanks to you, but one thing I have spotted is the inverter on light seems to be on all the time it comes on a bit brighter when its inverting, am I getting past it or what, I’m sure with the control sw in the middle position this green light was off, what’s your views on the subject, Thanks a lot M8y. Steve.

[oztules]

My unit is not normal now, and only has a spst switch..... so I cant recall... but I expect it should be OFF in the middle position.....

[steve3]

Thanks for the quick reply John, I wonder if there is anyone who has done the mod with the choke and can confirm that the green inverter light is off when the unit is just sitting there with the batteries connected, the sw in the middle position, many thanks. Steve.

[mab]

Well I didn't do the mod (my pj LF8000 24v came pre-modded with toroids), but when the switch is off (centre) all the lights are off.

m

 

[steve3]

Thanks guys for all your help, although my pj 8000w is working ok to me, but it looks like I have a fault somewhere, must get the lid off again, ha. I will keep you posted. Steve.

[off the wall]

I wonder if the MPPT spikes you're mentioning that trip out high voltage detection can be killed . . . ?

I tend to keep battery rejuvenators on my battery banks all the time and don't want those spikes to enter the inverter. It's a 24V system and I'm running a 8000LF Power Jack inverter. To connect the inverter to the battery bank I use 6 wires of 6mm solar cable (I run red and black colour coded cable throughout my offgrid system, by the way) to connect the inverter to the bus bars which are made of 25mm x 3mm lightning conductor - which is in parts copper or brown PVC covered aluminium for positive and aluminium, covered grey or black PVC for negative.

The reason why I use the 6mm solar cables (only about 1m length) is that I run them through ferrite cores on the way - cheap 1 inch diameter cores and two turns of 6mm go easily through each core.

By doing this I have not had overvoltage cutout on the inverter . . .

Best wishes

OTW