JohanG Posted July 23, 2019 Share Posted July 23, 2019 I have installed a Axpert MKS Plus 3kVA 2400W 24V Hybrid Inverter and Blue nova BN26V-154-4k No solar panels at present only running off ESKOM for the time being All household water is from 4 x 1000l rainwater tanks A 0.75kW pump kicks in when a tap is opend When the pump kicks in the Axpert beeps once sometimes twice probably indicating overload?????? This has to relate to the startup of the pump The inverter is rated 3kW Any views on the subject would be appreciated Quote Link to comment Share on other sites More sharing options...
Coulomb Posted July 23, 2019 Share Posted July 23, 2019 14 hours ago, JohanG said: A 0.75kW pump kicks in when a tap is opend An induction motor's surge current is usually about 7x the rated current. So it will be of the order of 750 x 7 = 5250 VA (with a poor power factor, though starting under load it will draw plenty of real power as well). That's pretty close to the surge rating of the inverter (6000 VA). Can you check the battery voltage to see if it dips during a startup? A multimeter with a min and max function would be ideal, to catch the instantaneous voltage drop. Is your wiring up to scratch? 3000 W plus about 10% at 25 V is some 132 A, so your battery cable needs to be able to handle that continuously. You'll need a stout fuse as well. Check for arcing / burn marks on the fuse and fuse holder; perhaps the Nova isn't so good at limiting in-rush current. It may be possible to suppress the beeps with settings, but first you should ensure that it's not trying to tell you something important. A new LFP battery will take some time to get its cells all balanced; during that time, it may not get charged fully. So the situation may improve over time. Quote Link to comment Share on other sites More sharing options...
JohanG Posted July 24, 2019 Author Share Posted July 24, 2019 Thanks Coulomb Since I started with solar I stand amazed at the complexity of the subject as well as the knowlage on this forum Quote Link to comment Share on other sites More sharing options...
JohanG Posted July 24, 2019 Author Share Posted July 24, 2019 Would installing a pressure tank be a solution The pump will then only be needed when the pressure drops reducing the frequncy that the pump is activated? Quote Link to comment Share on other sites More sharing options...
Jaco De Jongh Posted July 24, 2019 Share Posted July 24, 2019 On 2019/07/23 at 10:15 AM, JohanG said: A 0.75kW pump kicks in when a tap is opend 16 minutes ago, JohanG said: Would installing a pressure tank be a solution As a rule I install a 60 liter pressure tank for all my clients with pressure pumps when I install solar. Its much kinder to the batteries at night as well. I would recommend it. I prefer them running longer, but less frequent, rather than starting every time you open a tap. Quote Link to comment Share on other sites More sharing options...
Dex_ Posted August 15, 2019 Share Posted August 15, 2019 On this topic, is such a "large" motor/pump needed for a water tank application like this? I want to put in a water tank and having solar I need to consider this. Quote Link to comment Share on other sites More sharing options...
DeepBass9 Posted August 15, 2019 Share Posted August 15, 2019 On solar, as Jaco says, it is preferable to have a smaller pump running for longer, than a big pump pulling lots of current for a short time. Quote Link to comment Share on other sites More sharing options...
Dex_ Posted August 16, 2019 Share Posted August 16, 2019 13 hours ago, DeepBass9 said: On solar, as Jaco says, it is preferable to have a smaller pump running for longer, than a big pump pulling lots of current for a short time. yes but that involves a pressure tank, i am basically asking could you do it without a pressure tank but with a smaller motor? Quote Link to comment Share on other sites More sharing options...
DeepBass9 Posted August 16, 2019 Share Posted August 16, 2019 No idea, my water is all gravity fed by tanks. Dex_ 1 Quote Link to comment Share on other sites More sharing options...
Lionheart Posted August 28, 2019 Share Posted August 28, 2019 I pump from my borehole to a 5000l pump that feeds the house. The pressure pump I use is on my inverter. I use the DAB Esybox mini 3. It's quite expensive but well worth it. Its an inverter pump, and best of all keeps the pressure the same all of the time. even better than munic supply. As the requirement increases, the pump ramps up. ___ and root 2 Quote Link to comment Share on other sites More sharing options...
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