Good day

I recently installed a system at my grandma's house and setup the system to operate in UPS mode. The intention is to add panels to this system in time. The system works good ( 5kw Kodak VMIII with a US3000c battery).

However when the inverter is in line-mode (grid available), the inverter tends to switch on its fan periodically (+- every 10minutes)for about 1minute and then off again. The previous off-grid inverters from voltronics did not do this. Their fan only switched on when inverting from battery (Grid not available).

So is this related to a setting on the inverter that i missed or selected something incorrectly or is it in an embedded function of the inverter.  Don't get me wrong, if the temp sensor pics up that the invert is hot and need forced cooling, then I am all for the fan switching on. It is just a little bit irritating... especially when you know the grid is just passing through the inverter.

Please if somebody can advice

Thank you

4 hours ago, JR84 said:

So is this related to a setting on the inverter that i missed or...

I don't believe so. Fan operation of the Value Models (VM series) is a bit mysterious. I think it's one of the prices that you pay (so to speak) for the cheaper models.

I may be completely off the trail, but my guess is that you selected the battery type as PYL? 

If this is the case, the PYL settings for most versions of the firmware set the max and float voltages to be the same (settings 26,27). Many people have the same issue. 

The only way around it that I have been able to find is:

1) Change your battery type to USE and set the float voltage yourself, or

2) I see lots of mentions of this being addressed with later versions of the firmware.

My inverter/battery setup (Axpert VMIII 3KW/Pylontech UP2500) did exactly the same. I adjusted the voltages according to this post 

 
and its being behaving well. I am attempting to get updated firmware from the supplier, which is taking a awhile.

Did anyone figure out how to stop the fan running in linemode?

I recently got a VMIII (Kodak 5kW) and the fan runs 30 minutes on and few minutes off, but all on bypass. Anecdotally, it runs permanently on a sunny day. Baseload in the house is about 1A, so even the passthrough current is negligible. I have it purely as a back-up and the battery is just floating(don't have loadshedding at present). I have no idea why it needs to produce heat in standby, to the point where it needs forced cooling.