June 20, 20197 yr HI Guys recently installed 2x Axpert in parallel. Previous installations the inverter came on with batteries. This installation the inverters came on with PV. Is this normal?
June 21, 20197 yr On 2019/06/20 at 5:57 PM, Fazil said: This installation the inverters came on with PV. If the inverter is off, it's normal to "wake up" when PV is applied. But normally it requires batteries for that to work. Are you saying it came on with PV and no battery?
June 21, 20197 yr 3 minutes ago, Coulomb said: Are you saying it came on with PV and no battery? Once, ONCE I switched the inverter off, then the DB breaker to it, then I disconnected the batteries. To test all was off I switched the inverter back on and ... low and behold ... it powered up again feeding the loads with NO Eskom and NO batteries! I forgot to switch the panels off. 🤣
June 21, 20197 yr 3 minutes ago, The Terrible Triplett said: it powered up again feeding the loads with NO Eskom and NO batteries! Right, but that was a grid tie system, right? I believe that some Axperts, some of the ones with the 450 V MPPTs, actually can do this too. Edited June 21, 20197 yr by Coulomb "basically" → "some of"
June 21, 20197 yr 2 minutes ago, Coulomb said: ... that was a grid tie system, right? Correct. But by switching the main breaker from the DB to the inverter off, it was "off-grid". Would also have worked with that main breaker from the DB left on. But I thought it was enough for one day and did not want to try that. 🙂
June 21, 20197 yr Let me also note that the REASON why it worked with Eskom and batteries disconnected, was because the MPPT is connected direct to the inverter's battery connections. That is why it "thinks" there is a battery.
June 21, 20197 yr 2 minutes ago, The Terrible Triplett said: That is why it "thinks" there is a battery. It doesn't know where the DC is coming from. The solar chargers are also fairly accurate in the voltage they create and will charge the capacitors on the DC bus to whatever you told it, and if the AC loads are nice and smooth and don't draw large amounts of power faster than the MPPT can adjust, it will work just fine in this manner... You can disconnect a Multi completely, and then turn it back on afterwards... and it will run from its internal capacitors for several seconds.
June 21, 20197 yr 1 minute ago, plonkster said: ... and it will run from its internal capacitors for several seconds. And THAT is why I always switch it on after everything is disconnected BEFORE I open it or what not.
June 21, 20197 yr Author 2 hours ago, Coulomb said: If the inverter is off, it's normal to "wake up" when PV is applied. But normally it requires batteries for that to work. Are you saying it came on with PV and no battery? Yes brand new inverters Mecer brand MK2 in parallel. So when it switches to battery at night, there is about 2 second change over delay and this is driving me nuts. I will be fitting a change over external contactor soon to see if that improve the switching time.
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