nuevoboy Posted November 11, 2010 Share Posted November 11, 2010 First of all an apology to all 33 of you who opened this thread to find a blank message. *-) I hope you'll bear with me on this question, as I'm a bit flummoxed. Our "Motor-camper" had a replacement water pump fitted prior to our purchase. Having different manuals in the 'van has lead me to establish that it's a Posiflow 3001 (151-2103). Reading the manuals (and the conversion handbook) has lead me to understand that the pump should operate for 1 second, then have an "off" period for 2 seconds etc. Our pump simply "chatters" while the taps are open, continuing for a few more seocnds after they're turned off. Friends I have discussed this with say that their's operate similarly to ours. The manuals all say to turns a screw up to one-and-a-half times to elicit the "off" period; however, what screw, I no not. Can you please tell me if our pump is operating correctly or do I definitely need to introduce this 2 second "off" period somehow. Thank you. Link to comment Share on other sites More sharing options...
nuevoboy Posted November 11, 2010 Author Share Posted November 11, 2010 Photo of pump hopefully attached: Won't accept the photo sorry, and it's only a 240kb file. Link to comment Share on other sites More sharing options...
lennyhb Posted November 11, 2010 Share Posted November 11, 2010 Photo's need to be under 100k for posting. Link to comment Share on other sites More sharing options...
nuevoboy Posted November 11, 2010 Author Share Posted November 11, 2010 Thanks Lenny. This one's now down to 98k, but not very good. Link to comment Share on other sites More sharing options...
nuevoboy Posted November 11, 2010 Author Share Posted November 11, 2010 Aarrggh! How do I get rid of it????????????????? Sorry folks. Link to comment Share on other sites More sharing options...
Derek Uzzell Posted November 11, 2010 Share Posted November 11, 2010 I suspect you’ve got a slightly earlier version of this pump http://www.posiflo.info/html/7_l_m_12v.html as the Model Number you’ve quoted is virtually the same. Details of the pump are in the 3 downloadable files on the Posiflo website. If you view the “Spare Parts” file, you’ll see “1 – Switch Assembly”. The Switch Assembly is attached to the front end of the pump where the red 12V-supply wires are shown in the photo. The adjustment screw you don’t know about is the screw in the centre of the disk on the outer end of the switch assembly. The adjustment screw may need twiddling to reduce the sensitivity of the pump’s pressure-switch should the pump be reluctant to shut down (or start up), or if the pump is regularly starting up even when the taps are turned off. However, your description of how your pump is operating sounds to me like it’s working normally. It's usually obvious when this type of pump is not working properly, so I suggest you leave it alone. Link to comment Share on other sites More sharing options...
Brambles Posted November 11, 2010 Share Posted November 11, 2010 You need to change the physical image size when you are making it smaller, not just te resolution. Might be best to start a new thread and copy this pic.... Link to comment Share on other sites More sharing options...
Brambles Posted November 11, 2010 Share Posted November 11, 2010 I think the screw you need is in the center of the switch assembly, which in your case is pointing vertically down. If you look at the end of the pump end, then screw is in center. I am sure that is the one, as I can not idendentify any other screw it could be. parts list here Link to comment Share on other sites More sharing options...
Brambles Posted November 11, 2010 Share Posted November 11, 2010 Sorry Derek. missed your post explaining. Link to comment Share on other sites More sharing options...
Robinhood Posted November 11, 2010 Share Posted November 11, 2010 nuevoboy - 2010-11-11 6:06 PM Our pump simply "chatters" while the taps are open, continuing for a few more seocnds after they're turned off. Friends I have discussed this with say that their's operate similarly to ours. The manuals all say to turns a screw up to one-and-a-half times to elicit the "off" period; however, what screw, I no not. Can you please tell me if our pump is operating correctly or do I definitely need to introduce this 2 second "off" period somehow. Thank you. If the pump starts reasonably promptly once you open a tap, and turns off reasonably promptly after closing it (a few seconds or so delay are fine), then I would leave well alone. In case you don't know the following; It will almost certainly be controlled by a diaphragm pressure switch attached to the pump outlet. Opening a tap allows the water pressure to fall, the diaphragm moves and a switch on the outside of the diaphragm 'makes' electrical contact in the pump circuit. The pump will then work until the tap is closed; pressure builds up behind the diaphragm, and eventually 'breaks' the switch, switching the pump off. You would only normally carry out adjustment if the pump either didn't start or stop under the above conditions. Turning the screw on the pressure switch effectively changes the pressure differential that needs to be applied to get the diaphragm to move. The behaviour of yours sounds perfectly normal. (FWIW, I have had *some* problems with pressure switches in the past, and had to either dismantle or adjust them, but the commonest behaviour I've experienced is 'lazy' switching after the system has not been used fro some time. This usually self-corrects after a bit of use, and without any adjustment). Link to comment Share on other sites More sharing options...
nuevoboy Posted November 11, 2010 Author Share Posted November 11, 2010 Gentlemen, thanks for those explanations. I think I'll leave alone for now as Derek suggests. * Anyway at least until I've trained as a contortionist. Thanks to Brambles for identifying the problem with the photo. Now I know what widescreen sets are for, though. I think I'll leave that alone too in case I mess it up even more. * And Robin too - his post came in after mine, somehow. Link to comment Share on other sites More sharing options...
Andy_C Posted November 11, 2010 Share Posted November 11, 2010 Pump 'chattering' or cycling can be reduced by adding an accumulator to the system. It should greatly reduce the problem of pump cycling. Something like this one: http://www.marcleleisure.co.uk/store/accumulator-fiamma-expansion-tank-p-596.html It acts as a pressure reservoir and means that the pump runs a bit longer before switching off and takes a bit longer before switching back on again. Andy Link to comment Share on other sites More sharing options...
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