sharpener Posted July 21 Share Posted July 21 (edited) 15 minutes ago, dpmiller said: As it's a matched VFD I'd expect the colours codes to be a match If only it were that easy. Terminals are U, V, W. Wires are brown, grey, black (though not in that order). Go figure! I guess we will find out shortly, if @Hastings is still with us. Edited July 21 by sharpener Link to comment Share on other sites More sharing options...
Hastings Posted July 21 Author Share Posted July 21 (edited) 50 minutes ago, sharpener said: Yes swap the wires going to terminals marked V and W. Good luck! OK, but if L1,L2,L3 corresponds to U,V,W / Brown,Black,Grey then I have all 3 wires in the wrong places! Is it not safer to check with the supplier tomorrow? Edited July 21 by Hastings Link to comment Share on other sites More sharing options...
sharpener Posted July 21 Share Posted July 21 19 minutes ago, Hastings said: OK, but if L1,L2,L3 corresponds to U,V,W / Brown,Black,Grey then I have all 3 wires in the wrong places! No it does not matter. As others will be able to confirm all three windings on the motor will be identical. And all three outputs of the VFD are electrically equivalent to each other, except for a 120 degrees phase difference in the waveform (see Wikipedia article). So it makes no difference which is connected to what, there are six possible ways. However for 3 of the six the motor will run in one direction and for the other 3 in the other direction. Swapping any two wires - as @dpmiller also recommends - will change the direction. I was only joking, there is no danger to you, the VFD or the motor in trying it out. 1 Link to comment Share on other sites More sharing options...
Hastings Posted July 21 Author Share Posted July 21 BINGO! Swopping over black and brown seems to have fixed things entirely. Can now set the static pressure up to 2.5 bar (haven't tried higher yet as I haven't got time right now to check for leaks in the house) and the pump now draws up to only 600W or so. I can't tell you how happy I am and how grateful I am for everyone's help. Max cudos and thanks to @sharpener of course for taking quite so much trouble. 1 Link to comment Share on other sites More sharing options...
sharpener Posted July 21 Share Posted July 21 It's been an enjoyable ride and am so pleased for you. Just glad we could all help, that's the power of BuildHub. If it now draws only 600W (don't quite understand why that might be but an added bonus) then maybe it will run without crashing your battery so much, keep us posted about that too. Link to comment Share on other sites More sharing options...
Hastings Posted July 21 Author Share Posted July 21 1 hour ago, sharpener said: So it makes no difference which is connected to what, there are six possible ways. However for 3 of the six the motor will run in one direction and for the other 3 in the other direction. So is there a possibility that I can get even better performance by making another change in the wiring? I mean... could it have been running originally at 1/3rd performance, now is running at 2/3rds capacity and that there is still another wiring correction to make to reach 100%? Link to comment Share on other sites More sharing options...
JohnMo Posted July 21 Share Posted July 21 23 minutes ago, Hastings said: So is there a possibility that I can get even better performance by making another change in the wiring? I mean... could it have been running originally at 1/3rd performance, now is running at 2/3rds capacity and that there is still another wiring correction to make to reach 100%? Just test against it's pressure flow curve. At full speed and closed head (zero flow) it should produce around 5 Bar (check your curve for exact pressure or head). If your making close to 5 Bar your connected correctly and achieving full speed 1 Link to comment Share on other sites More sharing options...
sharpener Posted July 21 Share Posted July 21 1 hour ago, Hastings said: So is there a possibility that I can get even better performance by making another change in the wiring? I mean... could it have been running originally at 1/3rd performance, now is running at 2/3rds capacity and that there is still another wiring correction to make to reach 100%? Sorry to burst your bubble but the motor can only turn clockwise or anticlockwise, there is no Third Way! 3 of the wiring options give one and the other 3 the other as upthread. There is no more to be had, focus now on seeing if the Victron inverter behaviour has got any better. 1 Link to comment Share on other sites More sharing options...
Hastings Posted July 21 Author Share Posted July 21 Minor update: The pump IS after all running up to almost full power consumption 1.1kW, not just up to 600W as I posted earlier, which was what I recorded in response to a short toilet flush. However, it does so for a much much shorter time and starts slowing down towards a stop once the demand ends, far sooner than before. So quite a bit less power is being consumed per litre pumped than previously. Link to comment Share on other sites More sharing options...
sharpener Posted July 31 Share Posted July 31 Hello @Hastings. Did reversing the motor direction make any difference to the problem of the pump tripping your battery inverter system? Link to comment Share on other sites More sharing options...
Hastings Posted August 1 Author Share Posted August 1 Difficult to answer that precisely at the moment because at this time of year the battery bank stays fairly well-charged all of the time and there is mostly only me occupying the house and using water. But looking at the power meter when water is flowing I can see that maximum power draw (1200W) appears to be rare and even then very brief. The filling of the toilet cistern which is the most frequent demand draws a maximum 450W or so. The shower running is about the same. A slow flow from a tap settles at about 350W. Compare that with the previous situation (pump running in reverse) when the pump always ran up to 1200W for every and any level of demand and you're talking an improvement in power saving of, I am guessing, at least 4 or 5 fold. Never mind the all-important but now almost non-existent maximum peaks that were causing low battery voltage shut downs. I have 3 people staying next week which will be a much better test of the batteries. [Note for readers new to this thread: battery bank is 48V lead acid, original capacity 10kWh (at max 50% discharge) now about 1-2kWh] Link to comment Share on other sites More sharing options...
sharpener Posted August 1 Share Posted August 1 26 minutes ago, Hastings said: [Note for readers new to this thread: battery bank is 48V lead acid, original capacity 10kWh (at max 50% discharge) now about 1-2kWh] Sounds like the VFD is now doing a proper job of controlling the power according to demand. But given what you asay about the history of the batteries I would guess that as well as reduced capacity they have now got quite a high internal resistance so the terminal voltage drops a lot when under heavy load, possibly getting down to the lower limit on the Victron. Investment in newer/bigger/better batteries might be called for. You can check the battery voltage reading from the Victron front panel and see the effect of turning on e.g. a kettle or water heater. IIRC 46V is when things stop working properly. Even my brand new 7.1 kWh Pylontech stack had this issue. So in winter it would struggle to boil the kettle first thing when down to <20% SoC after powering the house all night. Have now added a third module to increase it to 10.65 kWh and is now a good deal better. Link to comment Share on other sites More sharing options...
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