June 13, 20232 yr 26 minutes ago, Peter Topp said: Hi Scorp007 How will this work? as soon as you open a tap the pressure drops it will start the pump. A pressure tank works because of the two setpoints for the start and stop of the pump from the pressure switch, as well as the 1.8bar pressure on the bladder. The pressure switch AFAIK also has a differential. It then works just like a compressor. At filling stations you can sometimes hear the compressor starting as you pump a car tyre. Only as the pressure drops to the lower level does the pump start and pressurises this reservoir to the higher level to stop the pump. The bladder is only there to reduce the shock effect when the pump starts. This piece of 150mm pipe is like a small tank as used on a compressor. Edited June 13, 20232 yr by Scorp007
June 13, 20232 yr 1 hour ago, Scorp007 said: The bladder is only there to reduce the shock effect when the pump starts. On the DAB it is (also, but primarily) there to keep the system pressurized so that when you open a tap, the water flows (and then the pressure drops and the pump starts).
June 13, 20232 yr 1 hour ago, P1000 said: On the DAB it is (also, but primarily) there to keep the system pressurized so that when you open a tap, the water flows (and then the pressure drops and the pump starts). Fully agree it serves 2 functions. The pipe will also help to keep pressure longer between starts. It would be interesting to know if the current range of PCB type of pressure transducers used also has the differential we have on electro mechanical units.
June 13, 20232 yr Hi All... My 5c worth I have had a solar borehole pump for over 12 years. I am actually on my second one since lightning took out the first controller box and last year the pump motor's bearings started to fail. It is a completely separate off-grid solution. It was the smallest one I could get at the time (50m head and 3000L/H from a dedicated 185W panel). It has served me so well that earlier this year when a hose was left open and we had to start the 3-phase pump in another borehole, the water from that hole had gone stale. I also don't have a pressure pump, since the water is pumped directly into a Jojo standing 6M high, and all the plumbling was done with 22mm piping. (I had to remove some flow restrictors from taps and showerheads) I live on a farm out of town and the pump supplied 2 households and 6 horses.
June 13, 20232 yr @Raiden2912 Main reason for going for the VSD pressure pump, in my opinion at least, is that it avoids the large rush of current required by induction motors to get them started. As I am sure you are aware, a 0.75kw induction motor can pull a 3-6kw quite easily load for a few seconds while it is starting up. If your inverter is offgrid and is running a few geysers etc it can be pretty close to it's limits and having a booster pump that is constantly switching on/off will increase the chances of tripping the inverter out due to overloading. A VSD motor doers not require the large inrush currents as is has a gradual increase in speed of the motor requiring much less current.
June 13, 20232 yr Hi A bladder tank not only does the things you mention above not only for the shock but also allows you to use about 50% of the capacity of the tank before the pump starts. I am not convinced the pipe will not be able to stop the frequent on/off cycles as it does not have the external pressure on the pipe to make much difference that a pressure tank has on the bladder. I see what you are saying there will be a little pressure from the pressure exerted on the pipe for it to expand from the water pressure as water cannot be compressed, then released when a tap is opened (only if you use a pipe that will expand and contracts and returns to form). However, it still does not compare to a pressure tank to stop frequent stop-and-start cycles. The mathematics says that to get a 10L difference which will need to expand 10mm over 3 meters to make a difference. I do not think a 115mm pipe would expand by a 10mm diameter and contract. 5mm for 5L etc. Edited June 13, 20232 yr by Peter Topp
June 13, 20232 yr Hi The calculation was done on a 150mm diameter pipe for 3m so I believe the Boere myth is truly busted. Edited June 13, 20232 yr by Peter Topp
June 14, 20232 yr On 2023/05/27 at 8:26 AM, Raiden2912 said: 70m Borehole Just some advice on boreholes and non-return valves... I learned the hard way which wasted months of my time and about R10k on an unnecessary replacement pump and motor. Your borehole pump will have a non-return valve built in, but you should add another external non-return valve within 7m of the pump (mine is directly on top of the pump) as the internal valve will not handle the pressure of 70m of water hammer when the motor stops and will probably fail over time. My water level is at 120m with a 1.1kw motor and a non-return at the surface and it took 2 months for my pump to fail and no longer start under pressure due to high current draw. After getting a lot of bs advice that my panels were wrong, my solar vsd probably needed replacing, then a new motor and then a new pump, I fixed it by adding a non-return valve above the pump and voila, all works perfectly again with original pump and motor. You should also have a non-return valve on approx every 50m of pipe to reduce water hammer damaging your pump and connections etc. I think it's good practice to make everything last longer. Welcome to the world of boreholes and pumps, it is much like the solar world with lots of cowboys and plenty of sales people who don't know what they are talking about. Edited June 14, 20232 yr by jumper
June 22, 20232 yr Author On 2023/05/29 at 11:31 AM, Robbo said: Wait for the analysis report, there is no way the installer can guess at this stage what the level of corrosiveness will be. There should be a line with "LSI" on it and you can take it from there: https://www.lenntech.com/calculators/langelier/index/langelier.htm LSI (Carrier) Indication: -2,0<-0,5 Serious corrosion -0,5<0 Slightly corrosion but non-scale forming LSI = 0,0 Balanced but pitting corrosion possible 0,0<0,5 Sligthly scale forming and corrosive 0,5<2 Scale forming but non corrosive Still waiting to see about mine as well, I'm using little bits still to keep the estimates lower in the future should there be a problem. I’ve received my report back. not sure yet how to read this…any help will be highly appreciated. Edited June 22, 20232 yr by Raiden2912
June 22, 20232 yr 2 hours ago, Raiden2912 said: I’ve received my report back. not sure yet how to read this…any help will be highly appreciated. Its a different lab from the one I used so not sure what the conclusion on it is. And can't seem to find the HCO3- (bicarbonate) value to plug into the link I posted. Hopefully the installer or someone here can help more
June 22, 20232 yr Hi Raiden 2912 After going through your report your water looks perfect for consumption. The only figure that is not in specification is the turbidity (cloudiness). This can be due to being a new borehole with still some solids and is common with newly drilled boreholes. This can be overcome just by putting in some filters to trap the solids. The turbidity should improve as the borehole is used over time. As far as the ph. goes you cannot get better as it is totally neutral ph7 which is not acid and not alkaline and will not damage anything. I don't know if a report analysis was attached. This is all I can see from the report. I am not an expert at this and I might have missed something. I suggest you should have the borehole checked again after a year or two as in my case the ph. had changed after a year. I think the HCO3 (bicarbonate) value would be the amount of carbon dioxide dissolved in the water which makes it more acidic and would be more prevalent in rainwater as it absorbs CO2 on the way down. I do not think it has any bearing on the report as the ph. is 7 (I could be wrong). Edited June 22, 20232 yr by Peter Topp
June 22, 20232 yr Author Thank you so much Peter and Robbo. so on this on the report I’m a little concerned about is the Heterotrophic Plate Count? Check the recommended and what was picked up. I’m not sure how to fix that. Still doing research cause the report also says draft for some reason. They should offer some guidance per the diagnosis as well. this is awesome though. Thank you so much
June 22, 20232 yr 43 minutes ago, Raiden2912 said: Still doing research cause the report also says draft for some reason I think this may be because there is a value pending for "Total organic carbon as C" which is listed as a chronic health risk, so I guess they will wait for those test results first before sending the final. As for the Heterotrophic plate count, I don't think it's too serious as they don't have a limit for it and it is listed as an operational risk, not health risk, so I think it is more about wearing impellers and clogging pipes like the turbidity. They have tested for coliforms which are a health risk separately by the looks of things. You might also find that this is related to a new borehole as organic material from the surface will have entered the hole during drilling. Wait for the final report, I'm sure they will give some guidelines on any health risks.
June 22, 20232 yr Hi After reading up on the Heterotrophic plate count there are indications that the count should be less than 500 however, a larger count does not mean that the water is a problem as the bacteria could be harmless. If you want to eliminate and lower this you can implement the following. A UV light source would be the best bet as it damages the DNA in the microbes. Adding an activated carbon filter also helps. Using continuous chlorination, however, the chlorine will have to be reduced by carbon filters before it is drinkable and helps with the taste. Excess chlorine is not good for you. Doing reverse osmosis will also help to remove bacteria. You could also boil the water for consumption before anything else is implimented in you are worried which also works. Edited June 22, 20232 yr by Peter Topp
June 22, 20232 yr Author 2 hours ago, Peter Topp said: Hi After reading up on the Heterotrophic plate count there are indications that the count should be less than 500 however, a larger count does not mean that the water is a problem as the bacteria could be harmless. If you want to eliminate and lower this you can implement the following. A UV light source would be the best bet as it damages the DNA in the microbes. Adding an activated carbon filter also helps. Using continuous chlorination, however, the chlorine will have to be reduced by carbon filters before it is drinkable and helps with the taste. Excess chlorine is not good for you. Doing reverse osmosis will also help to remove bacteria. You could also boil the water for consumption before anything else is implimented in you are worried which also works. So have a 3 stage filter system with UV and that’s also what’s concerning me 2 hours ago, Peter Topp said: Hi After reading up on the Heterotrophic plate count there are indications that the count should be less than 500 however, a larger count does not mean that the water is a problem as the bacteria could be harmless. If you want to eliminate and lower this you can implement the following. A UV light source would be the best bet as it damages the DNA in the microbes. Adding an activated carbon filter also helps. Using continuous chlorination, however, the chlorine will have to be reduced by carbon filters before it is drinkable and helps with the taste. Excess chlorine is not good for you. Doing reverse osmosis will also help to remove bacteria. You could also boil the water for consumption before anything else is implimented in you are worried which also works. Thank you so much Peter and Robbo. so on this on the report I’m a little concerned about is the Heterotrophic Plate Count? Check the recommended and what was picked up. I’m not sure how to fix that. Still doing research cause the report also says draft for some reason. They should offer some guidance per the diagnosis as well. this is awesome though. Thank you so much
June 22, 20232 yr Author So I have a 3 stage Puritec filter with UV and that’s why the concern. but again adding reverse osmosis at a drinking point in the house isn’t a bad idea Edited June 22, 20232 yr by Raiden2912
August 29, 20232 yr Hi everyone , we have sunk a 65m borehole and intend to split the borehole between 4 properties. I am trying to find a way to manage and split the supply of water to each house , any suggestions? I can’t seem to find any information on this type of setup.
August 30, 20232 yr 21 hours ago, Alex g said: Hi everyone , we have sunk a 65m borehole and intend to split the borehole between 4 properties. I am trying to find a way to manage and split the supply of water to each house , any suggestions? I can’t seem to find any information on this type of setup. Have you guy worked out what tank capacity each would have? Have you got test results of the water table? What is the likely water consumption for each of the 4 on a litre per day basis? What size pump do you have in mind? What is the highest head that the pump will have to pump? For calculation give this from above the ground level at the pump. Sorry for all the questions but one need information to try and work out some distribution.
August 31, 20232 yr On 2023/08/29 at 9:49 PM, Alex g said: Hi everyone , we have sunk a 65m borehole and intend to split the borehole between 4 properties. I am trying to find a way to manage and split the supply of water to each house , any suggestions? I can’t seem to find any information on this type of setup. If you are supplying multiple houses then it would be best to pump water straight into storage tanks above ground and then distribute from there to a tank at each house (preferably with gravity) and then have a small booster pump (375W) at each house for pressure. You might be able to do without the tanks and booster pumps at each house if the main storage area is high enough to provide good pressure to all. You can then set up the borehole with solar to pump all the water you can during sunlight hours into the storage tanks and use that at night. Your borehole is probably shallow enough to run a DC solar pump straight from panels, but I went the vsd route with a 3 phase ac pump as they are generally much cheaper and easier to get fixed and the range of choice is much bigger.
August 31, 20232 yr 30 minutes ago, jumper said: If you are supplying multiple houses then it would be best to pump water straight into storage tanks above ground and then distribute from there to a tank at each house (preferably with gravity) and then have a small booster pump (375W) at each house for pressure. You might be able to do without the tanks and booster pumps at each house if the main storage area is high enough to provide good pressure to all. You can then set up the borehole with solar to pump all the water you can during sunlight hours into the storage tanks and use that at night. Your borehole is probably shallow enough to run a DC solar pump straight from panels, but I went the vsd route with a 3 phase ac pump as they are generally much cheaper and easier to get fixed and the range of choice is much bigger. CFP have a Veichi Si23 Solar inverter that lets you drive up to a 4kw 3 phase borehole pump using either solar panels or a 230V single phase input. https://cfptechnologies.co.za/product/veichi-si23-d3-series/
August 31, 20232 yr 24 minutes ago, Sc00bs said: CFP have a Veichi Si23 Solar inverter that lets you drive up to a 4kw 3 phase borehole pump using either solar panels or a 230V single phase input. https://cfptechnologies.co.za/product/veichi-si23-d3-series/ Those look like nice machines. I went with a microcare 2kW 400V 3phase unit (R11k) as it looks a bit more outdoor friendly. It lives under the panels out in the mountains with +40C in summer and snow in winter and the microcare is built like a tank. It has performed flawlessly for a year now, even though their technical support was not very helpful when I needed it.
August 31, 20232 yr 1 hour ago, jumper said: If you are supplying multiple houses then it would be best to pump water straight into storage tanks above ground and then distribute from there to a tank at each house (preferably with gravity) and then have a small booster pump (375W) at each house for pressure. You might be able to do without the tanks and booster pumps at each house if the main storage area is high enough to provide good pressure to all. You can then set up the borehole with solar to pump all the water you can during sunlight hours into the storage tanks and use that at night. Your borehole is probably shallow enough to run a DC solar pump straight from panels, but I went the vsd route with a 3 phase ac pump as they are generally much cheaper and easier to get fixed and the range of choice is much bigger. Great idea to set the topic going forward. @Alex g can provide more details. If 4 houses close to each other. If 4 properties with quite a distance to pump the common tank might introduce a high loss of pressure/volume. You and I are perhaps the only 2 guys thinking for normal use a 375W pressure pump with low head and bladder will suffice per house 🤔🤔
August 31, 20232 yr 1 hour ago, Scorp007 said: You and I are perhaps the only 2 guys thinking for normal use a 375W pressure pump with low head and bladder will suffice per house 🤔🤔 I find a 375W DAB pump provides plenty of pressure and volume for a house of 2 people and they are cheap as chips, I can't put the shower on full blast or it hurts. I'm not sure if it will run 2 showers at the same time, but those things are manageable. I don't use a bladder tank as with 2 people the pump does't turn on that often and runs fine off my 3kW axpert without complaints, but with more people a bladder tank would be necessary to save the pump 👍 I think a single pump providing pressure to 4 houses is going to do too much work with all the switching on and off every time someone uses water.
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