Noobie Posted January 8, 2016 Share Posted January 8, 2016 So I am thinking of connecting my JoJo tanks pressure pump on to my inverter so that in the event of a power failure I won't have to go outside and turn the bypass valve on. I know, its me being lazy The pump is a 230V 850watt DAB pump, it pulls 3,8 amps running current. My concern is that the pumps start up current will trip the inverter output supply. The research I have done says that the startup current on a motor is between 3 and 5 times the running current (between 11,4amps and 19amps) The inverters surge power is 6000VA - 4800watts (3k 24v plus Mecer) @ 230 volts, this would equate to 20amps. So if I have done my calculations correctly the inverter will be able to supply enough current to start the motor without tripping out - 20amps max inverter surge output vs. 19amps motor startup current. This would be great if my pressure pump was the only thing connected to my inverter, but unfortunately this is not the case. If I am pulling a base load of 5 amps from the inverter and then the pump starts up this will push the current draw over the 20amp surge limit tripping out then inverter. I have done a bit of reading and think I may have a solution? A soft starter relay from RS components connected to the pressure pumps supply. Heres the link: http://za.rs-online.com/web/p/soft-starts/3305358/ Has anyone out there done something similar and had success or am I on the wrong path here? Quote Link to comment Share on other sites More sharing options...
Noobie Posted January 8, 2016 Author Share Posted January 8, 2016 Thanks JDP Great news, I have a pressure vessel so it should just be a question of installing the soft start relay. This forum is awesome! Quote Link to comment Share on other sites More sharing options...
___ Posted January 8, 2016 Share Posted January 8, 2016 Noobie, I have that exact same pump (DAB Jetcom, 0.85kw motor, 3.8 amp indicated on the motor), and my 1600VA Victron starts it without a hitch. The red overload LED flashes for half a second but that's it. This particular inverter can handle momentary peak power of 3kva. It's going to depend on how much other things are also on the inverter, but I haven't had a problem yet. Quote Link to comment Share on other sites More sharing options...
Noobie Posted January 9, 2016 Author Share Posted January 9, 2016 Thats good news, I will test it before I go out and buy the soft starter. I don't imagine that the base load will be more than 5 amps. Quote Link to comment Share on other sites More sharing options...
Wetkit Posted January 11, 2016 Share Posted January 11, 2016 Testing would be best if you already have the pump. You might find that the soft starter gives you a lower amp peak on startup, but it extends the duration of the peak. Quote Link to comment Share on other sites More sharing options...
___ Posted January 11, 2016 Share Posted January 11, 2016 My power failed at 5AM this morning (because I forgot to buy prepaid :-P), so this morning my irrigation system fired up the DAB Jetcom pump off the inverter... which is no biggie, except I had a couple of fans, DSTV PVR and a laptop or two, and a fridge running at the same time. So while I was in the garage punching in the newly bought code, the freezer decided to turn on. So ye olde Victron made this loud groaning Bzzznnnt noise, flashed the overload LED twice... and continued on its way, fans blowing as if it might take off. It's only a 1600VA unit... So really, I don't see why there'd be an issue starting this pump even without a soft starter. Ironman and Clint 1 1 Quote Link to comment Share on other sites More sharing options...
Novarein Posted July 2, 2020 Share Posted July 2, 2020 I know this is an old post, but want to check on feedback if the Soft Starer from RS-Online worked for the pumps. I also have the same issue with the PUMPS startup amps which Im trying to reduce as it overloads the inverter. Anyone else have experience with this setup will be greatly appreciated Quote Link to comment Share on other sites More sharing options...
Noobie Posted July 2, 2020 Author Share Posted July 2, 2020 I wound up having to replace my pump shortly after and have never bothered connecting it to the inverter. I got a DAB easy box mini I do have a bypass valve on the municipal supply so during load shedding I can use this valve to supply the house with water straight from council (bypassing the pressure pump and tank) I have only ever had load shedding and a Joburg water outage once. What I wound up doing was running an extension cord from an inverter socket and plugging the pump into this and it worked 100%. Quote Link to comment Share on other sites More sharing options...
Novarein Posted July 3, 2020 Share Posted July 3, 2020 Thanks for the feedback! Yeah I actually have the same setup though with a Borehole integrated into the water system. Looking at the specifications of the DAB E.SYS it doesnt go above the rated KW and only reaches its peak on demand. Ill have to just check the water flow as I have irrigation also with my 1.5kw pump (2.5 startup). This is useful, so maybe this is my better option on the long run! Quote Link to comment Share on other sites More sharing options...
Johan Rabie Posted July 9, 2022 Share Posted July 9, 2022 I have a 5kwatt Growatt inverter. My waterpump is a 0.6kwatt leo pump. It refuses to start early morning. When I unplug and insert the plug again it starts and work perfect during the day, until cold start the next morning. Please help, plugs and pump were changed with no success Quote Link to comment Share on other sites More sharing options...
Noobie Posted July 11, 2022 Author Share Posted July 11, 2022 Thats an odd one to solve... Maybe the capacitor on the pump is no good and discharging out its stored energy when not in use (at night) Or maybe it has something to do with the cold at night? Or maybe there is no non return valve to prevent water flowing back to the source, in turn slowly spinning the motor backwards when not in use, discharging the capacitor. Seeing as you have already swopped the pump and plugs, I would suggest looking at the non return valve first. Quote Link to comment Share on other sites More sharing options...
Scorp007 Posted July 11, 2022 Share Posted July 11, 2022 42 minutes ago, Noobie said: Thats an odd one to solve... Maybe the capacitor on the pump is no good and discharging out its stored energy when not in use (at night) Or maybe it has something to do with the cold at night? Or maybe there is no non return valve to prevent water flowing back to the source, in turn slowly spinning the motor backwards when not in use, discharging the capacitor. Seeing as you have already swopped the pump and plugs, I would suggest looking at the non return valve first. Just something on the capacitor. Most if not all capacitors have a built in resistor to discharge and prevent a shock should you switch off the pump. The capacitor will charge up at 50Hz when power is switched in to create the split phase in order to turn when used on a single phase. Have no idea why a 5kw cannot start the pump. @johan Rabie Have you tried disconnecting the pump before the 1st start in the morning to see if it fails. Yes I know it doesn't make sense. Quote Link to comment Share on other sites More sharing options...
Conrad Botts Posted December 6, 2022 Share Posted December 6, 2022 We sits also with a single phase 0.75 kw presser pomp.when start up trips the breakers. some sagest a soft starter, but some say no, the soft drops the volts and the amps increase. so it will overload again. so someone else say we must use a ME-drive, but it is a single phase in and 3 phase out, so its not gone work. any suggestion. Quote Link to comment Share on other sites More sharing options...
Johandup Posted December 7, 2022 Share Posted December 7, 2022 How big is the breaker and how old is it? Sometimes it is worth it to replace it to ensure it is not the problem. A mcb can trip on overload as well as a short. Quote Link to comment Share on other sites More sharing options...
Scorp007 Posted December 7, 2022 Share Posted December 7, 2022 18 hours ago, Conrad Botts said: We sits also with a single phase 0.75 kw presser pomp.when start up trips the breakers. some sagest a soft starter, but some say no, the soft drops the volts and the amps increase. so it will overload again. so someone else say we must use a ME-drive, but it is a single phase in and 3 phase out, so its not gone work. any suggestion. I find it interesting that we do see with valid reason why not to run any stuff at lower volts. Now... 95% of all induction motors over 7.5kW are started with star/delta starters to reduce starting current. 220/380V. This was the going old style starting method for decades before new tech got designed. The above is excluding slip ring induction motors. Correct me if I am wrong. Quote Link to comment Share on other sites More sharing options...
Vaal Posted December 25, 2022 Share Posted December 25, 2022 On 2022/12/06 at 3:39 PM, Conrad Botts said: We sits also with a single phase 0.75 kw presser pomp.when start up trips the breakers. some sagest a soft starter, but some say no, the soft drops the volts and the amps increase. so it will overload again. so someone else say we must use a ME-drive, but it is a single phase in and 3 phase out, so its not gone work. any suggestion. What size breaker/s does trip? You say breakers, is it the same 1 or different breaker? Or is it the earth leakage which trip? How thick is your supply cable and how long is it? If your start-up current is a bit too high for your breaker you can always use a curve 1 breaker, it takes about twice as long to trip for the same overload. It is the breaker with a orange toggle, it works quite well for motors, aircons and certain welding machines. Quote Link to comment Share on other sites More sharing options...
gmp Posted January 25 Share Posted January 25 I have to admit , that I don’t understand the intricacies of the inverter and pump but do know that with it connected , it takes up way too much power from the house. So my question.. is there not a type of “electric bypass” that can work on its own. Would alleviate having to turn the bypass on and off manually considering the amount of times we are load shed. Is there something like this out there? Quote Link to comment Share on other sites More sharing options...
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