Browse Forums Eco Living Re: Rinnai HWS & Pressure Tank 3Sep 10, 2016 2:18 am 3in1 Supadiverta. Rainwater Harvesting Best Practice using syphonic drainage. Cleaner Neater Smarter Cheaper Supa Gutter Pumper. A low cost syphonic eaves gutter overflow solution. Re: Rinnai HWS & Pressure Tank 5Sep 10, 2016 11:26 am 3in1 Supadiverta. Rainwater Harvesting Best Practice using syphonic drainage. Cleaner Neater Smarter Cheaper Supa Gutter Pumper. A low cost syphonic eaves gutter overflow solution. Re: Rinnai HWS & Pressure Tank 7Sep 10, 2016 12:02 pm 3in1 Supadiverta. Rainwater Harvesting Best Practice using syphonic drainage. Cleaner Neater Smarter Cheaper Supa Gutter Pumper. A low cost syphonic eaves gutter overflow solution. Re: Rinnai HWS & Pressure Tank 8Sep 10, 2016 12:40 pm 3in1 Supadiverta. Rainwater Harvesting Best Practice using syphonic drainage. Cleaner Neater Smarter Cheaper Supa Gutter Pumper. A low cost syphonic eaves gutter overflow solution. Re: Rinnai HWS & Pressure Tank 10Sep 10, 2016 1:31 pm If I pump the pessure tank up to say 52psi (have to experiment) to satisfy the pump it'll then only deliver maybe 5L before the pump kicks in. But yes, that might be the solution. It would solve the run on issue and still reduce pump starts for the quick rinses etc. It might also fix the shower issue as well, as the pump would start (depending on the pressure tank's charge level) after a maximum of say 30secs amd stay running at stable pressure for the whole shower. Hmmm. .. will give it a go and report back. Didn't even occur to me to up the pressure tank's psi. Thanks for thinking out of the box on that one. Re: Rinnai HWS & Pressure Tank 11Sep 10, 2016 6:43 pm firebird If I pump the pessure tank up to say 52psi (have to experiment) to satisfy the pump it'll then only deliver maybe 5L before the pump kicks in. But yes, that might be the solution. It would solve the run on issue and still reduce pump starts for the quick rinses etc. If the pump is the TLE-1A, it has a 35 metre head which is just under 50 psi or 343 kPa but you need to know what the pressure controller's pressure settings are as should have the plumber when he installed the pressure tank. The pump's handbook should state these. Raising the pressure tank's pressure to 52 psi won't prevent run on because the pump will run until it reaches the pressure controller's cut out setting plus the pressure tank would always have 53 psi in it! The pump head is the maximum pressure that the pump will run at (depending on the pressure controller's setting) and running a pump with a lot of head resistance will substantially slow down the flow and stress the pump. The 45psi cut out figure I used in an earlier post was not a recommendation for your pump, it was merely an example. As a further example, my Davey pump also has a maximum total head of 35 metres, the same as the TLE-1A. The Davey pump came from the factory with a small 8 litre pressure tank fitted and so the pressure controller was factory adjusted for the pump to work with the pressure tank. For my pump, the cut in and cut out pressure settings are 140 kPa and 280 kPa. I would not consider using this pump and pressure tank with a shower or an instantaneous gas HWS because the pressure is too low, the pressure variation is too great and there would be too much cycling. 3in1 Supadiverta. Rainwater Harvesting Best Practice using syphonic drainage. Cleaner Neater Smarter Cheaper Supa Gutter Pumper. A low cost syphonic eaves gutter overflow solution. Re: Rinnai HWS & Pressure Tank 12Sep 10, 2016 9:42 pm Ok, the penny has dropped. The controller is only adjustable for the cut-in. 1.5 - 3.5 bar. The cut-out is fixed at 8 bar (around 116psi), so we're back to square one. Now I see why the run on happens. The pump is trying to reach 116psi to cut out. Correct? If that's the case it's a wonder it cuts out at all. The guage on the controller quivers around the 4 bar mark for 3-4 mins then finally cuts out. I need a controller with an adjustable cut-out, if there is such a thing. Re: Rinnai HWS & Pressure Tank 14Sep 10, 2016 9:57 pm firebird The pump is trying to reach 116psi to cut out. Correct? The pump will only push to a 35 metre head. 1 metre = 1.42 psi or 9.81 kPa. It should cut out before that. 3in1 Supadiverta. Rainwater Harvesting Best Practice using syphonic drainage. Cleaner Neater Smarter Cheaper Supa Gutter Pumper. A low cost syphonic eaves gutter overflow solution. Re: Rinnai HWS & Pressure Tank 15Sep 11, 2016 8:44 am So basically a pump with one of these type fixed controllers will never work with a pressure tank. Too much run on. What must others use with a pressure tank? There's got to be a correct way to do this. I can't be the only person with the problem. The plumber seems to just shrug his shoulders. He says he rarely sees pressure tanks used. Our original plumber has moved. Re: Rinnai HWS & Pressure Tank 16Sep 11, 2016 10:17 am firebird So basically a pump with one of these type fixed controllers will never work with a pressure tank. Too much run on. What must others use with a pressure tank? There's got to be a correct way to do this. I can't be the only person with the problem. The plumber seems to just shrug his shoulders. He says he rarely sees pressure tanks used. Our original plumber has moved. A pump that comes with an electronic pressure controller operates with factory pressure settings that suits that particular pump. Electronic pressure controllers also have run dry protection because they sense when there is no available water. If the same pump and electronic pressure controller comes from the factory with a pressure tank, the tank's pressure will be set to 'X' and the pressure controller's cut in - cut out settings will be set at the factory to work with the tank's pressure. These settings are different to the standard settings and they also vary between different pumps and tank pressures. Most electronic pressure controllers are generic and interchangeable between different pumps. Electronic pressure controllers to suit pressure tanks are also available, for example, if the one on my pump failed, I can easily buy another with the settings I need. You can fit a manual pressure controller like the common square D pressure switch and these are adjustable. Their standard pressure ranges are 20/40, 30/50 and 40/60. Manual pressure controllers do not have run dry protection and their use with small tanks needs close monitoring which is not often practical. Unlike electronic pressure controls, manual pressure switches are virtually bullet proof. They have also being around for years and are widely available. https://www.youtube.com/watch?v=5WNbxu9ufPs It is best to have high settings to decrease pressure variations when a pump with a pressure tank is used for showers etc. There is a fair difference between a pressure variance of 20/40 and 40/60. While outwardly it would seem that they both have a difference of 20 psi which they do, the 40/60 is higher up the totem pole. Higher pressures require larger pumps, the reason that people look at pressure tanks with large pumps. When comparing the price of a large pump and a decent size pressure tank, VSD pumps that offer constant pressure, energy savings and a long life become very appealing. For your situation, you either need to disconnect the pressure tank or else change the pressure switch. EDIT: The electronic pressure controller in the link below is fully adjustable. http://www.theirrigationshop.com.au/shopping/proddetail.asp?prod=781 3in1 Supadiverta. Rainwater Harvesting Best Practice using syphonic drainage. Cleaner Neater Smarter Cheaper Supa Gutter Pumper. A low cost syphonic eaves gutter overflow solution. Re: Rinnai HWS & Pressure Tank 17Sep 11, 2016 12:57 pm Thanks for the info and your time with this. A new electronic pressure controller seems the easiest solution, if I can find something suitable. The D switch looks a bit tricky for me. The pressure tank is now set at 30 psi. The current pressure controller has an adjustable cut-in range of 22-50 psi (1.5 to 3.5 bar), & a cut-out at around 87 psi (6 bar). I imagine I'd need a new controller with a cut-out around 46 to 48 psi, or 3.2 to 3.3 bar. The pump is about 50 psi as you say. I can only find controllers with an adjustable cut-in, and most have a very high fixed cut-out. Typically 6 to 10 bar. I'll have to ring around the plumbing shops. I'd like to keep the pressure tank as the pump stopping and starting 100 times a day is not desirable. Re: Rinnai HWS & Pressure Tank 18Sep 12, 2016 12:32 am As a matter of interest, I have just found my pump's installation instructions...all such paperwork goes in the one cupboard! The plumber told me that the pressure tank had to be set at 20 psi but I have always had it a little lower than this because of early gremlins. The cut in - cut out settings are 140 - 280 kPa and so I decided to look for the instructions after I realised that 140 kPa is 20.3 psi. It turns out that the tank's factory pressure setting is 19psi. Still, 19 psi with a 20.3 psi cut in is a bit fine for my liking. I think that your intention to have a 46 to 48 psi cut out will be damaging to the pump and waste energy. 3in1 Supadiverta. Rainwater Harvesting Best Practice using syphonic drainage. Cleaner Neater Smarter Cheaper Supa Gutter Pumper. A low cost syphonic eaves gutter overflow solution. Re: Rinnai HWS & Pressure Tank 20Sep 12, 2016 12:54 pm firebird Oh, so if the pressure tank is 30 psi are you saying I only need a cut-out a few psi above that? I am somewhat hesitant to answer your question in this instance because a lot of people read these threads and their pumps and situations will be different and I would not want someone taking on board a recommendation given to you and using it for a different situation. The cut in pressure is always above the tank's pressure, if you persevere with the pressure tank, maybe initially try 3-4 psi above the tank's pressure. Also be aware that the pressure tank's pressure must be checked at least annually but preferably more frequently than annually. The tank must be drained before the pressure is checked and adjusted. Pump types vary as do the applications such as some properties having underground tanks or submersible pumps etc. I mentioned my Davey pump earlier because it also has a 35 meter head and we were discussing different pressure switch settings when pumps were fitted at the factory with a pressure tank but it is a centrifugal pump whereas yours is a turbine pump. Turbine pumps are known by various names and you can read about them below. The operating differences between centrifugal and turbine pumps are also explained. You Tube is also a good source of information. http://www.rothpump.com/regenerative-tu ... -head.html The statement below is taken from the link above. Regenerative turbine pumps should not be operated against a closed discharge, unless a pressure relief valve is used. Install a pressure gauge on the pump's discharge, observe the manufacturer's pressure limits and you'll increase the pump's life. A centrifugal pump usually has the cut in pressure 2 psi above the pressure tank's pressure but this also depends on the tank's elevation if applicable whereas some other types of pumps might require 5 psi. 3in1 Supadiverta. Rainwater Harvesting Best Practice using syphonic drainage. Cleaner Neater Smarter Cheaper Supa Gutter Pumper. A low cost syphonic eaves gutter overflow solution. First time building 2 storey home, is under construction (in Framing stage) in NSW. I have 3 toilets and need bidet spray in… 0 16910 Thanks for letting us know. The programmer will have a look at this later today. 2 6793 |