Hello Engineers,

Hope this post finds you well.  Why is it that Axpert King and always have Bus related faults especially Error 09.

Most times, it is very hard to identify the faulty the component that caused the error.

For an instance, i have a mainboard on my table right now, following the service manual, i have tested the IGBTs and its drivers, the MOSFETs and Its drivers, uc3854(u15). but i cant find any of them faulty but still, Error 09 occurring. i have tested if the C40 and C41 (500v/470uf) are charging......actual,  they charged but more than 500v as against the normal 380v - 400v.

Please what else do i need to test.

Best Regards.  

17 hours ago, victronics said:

actual,  they charged but more than 500v as against the normal 380v - 400v.

That sounds like the bus soft start circuit (basically a power supply) isn't turning off. 

Referring to the partial schematic trace (for an Axpert MKS, but may well be very similar), check for 5.2 V at pin 8 of U16, and check R250 and U17. Try a replacement control board if possible, otherwise trace back the connections to pins 1 and 2 of U17 (opto) back to the control board, probably through a buffer chip on the control board. But if pin 2 of U16 is going high (about 5.2 V) when the bus voltage reaches 350-400 V, then that's fine.

I can't think of much else that could cause the bus voltage to rise before the best soft start process is over. Actually, my reading of the bus soft start function is that it doesn't care how high the bus voltage goes, as long as the value it reads is more than a value that depends on the battery and mains voltages. Always between 280 V (for a 40 V battery) and 462 V (for a 66 V battery). So maybe it's misreading either of those? You may be able to check what it's seeing on the LC Display before the inverter shuts off. If both of these agree reasonably closely with a multimeter, then it has to be misreading the bus voltage. Check the resistive divider that cuts the bus voltage down to a measurable value; it likely has a string of high value (say 499 kΩ) resistors all in series. One of these may have gone open or not be soldered correctly.