Error 05

[bruce 1980]

good day.Got an axpert inverter installed 2 day ago now giving error 05 for output short circuit.what could be the problem which places do i check when repairing it .5Kva 48v inverter.Also is there anyone with repair manual with schematic diagram.thanks

[coulomb]

Got an axpert inverter ... 5Kva 48v inverter.

There are quite a few models that fit that description.

installed 2 day ago

Surely that should be fixed under warranty.

now giving error 05 for output short circuit.what could be the problem which places do i check when repairing it .

I assume you've isolated the output, to rule out an actual short circuited load. Fault code 05 is not terribly common. It occurs when in battery mode, the output voltage is less than 50 V, and the output current is > 20 A, all three criteria for 5 times in a row. I'm fairly sure that the 50 V criterion is 50 VAC, not instantaneous 50 V.

I'm guessing that it could be a shorted output component (e.g. a MOV, filter capacitor, relay contact). Presumably the inverter proper is working, otherwise it could not generate more than 20 A of output current. Shorted IGBTs would presumably cause fault code 09 (error 09) instead (bus soft start error, due to the bus being shorted). There isn't really a schematic trace of the inverter output, but after the inverter IGBTs there is just an LC filter (both large components, hard to miss, see also the second block diagram here), then the relays as shown in this block diagram. The MOVs are large components that are fairly easy to identify. If you decide to attempt repairing it, I suggest that you peruse the repair section of this topic (first post contains an index).

[Richo]

Most components wont survive 20A in a shorted state.
I'd go with the relay contacts welded or something outside the inverter (user error).

[coulomb]

Another thought: perhaps you have a load with a DC component, and it has magnetised your transformer. For example, some cheap hair dryers and apparently also heat guns (with a high and low power setting) use a diode to achieve the low power mode. This causes a large DC component in the output current, which can cause transformers to saturate and draw a lot of current. If so, demagnetising the high frequency transformer inside your inverter-charger may be possible and not too difficult.

Thinking about this some more, it seems to me that the excessive current drawn would be before the current sensor, so it would not "see" the excess current. However, that might cause the output voltage to fall dramatically, so that the error could be triggered by the 50 V AC lower limit, rather than the 20 A AC upper limit.