water pump short cycling

[jmtisme]

having a mare of a problem with a water pump short cycling myself and another spark have checked the electrical side and it is all good but still pressure switch makes and breaks about twice a second any help would be great or any pointers where to start thanks in advance guys

 

[malcolmsanford]

Is there a pressure vessel attached to it ? if there is the bladder might have a leak.

If it's a direct on line pump are the valves fully open or blocked as it seems you may have a supply problem.

 

[jmtisme]

there is a 500ltr pressure vessel on it but its sitting at the precharged pressure of 2 bar could the bladder still be knackered

 

[malcolmsanford]

Well you could have a dodgy pressure gauge, if you depress the schreader valve you should just get air, if the bladder is burst you also get water. Have you an air source or independent gauge, and what should the bladder be set at.

 

[jmtisme]

was factory set at 2 bar changed 4 pressure switches just recharged to just over 2 bar seems to be improving. will keep you posted thanks guys.

 

[Marvo]

If the bladder lost pressure then chances are it has a leak and needs replacing.

 

[malcolmsanford]

If the bladder lost pressure then chances are it has a leak and needs replacing.

Could be just a leaking schreader valve, often found even factory ones are sometimes loose.

Jmtisme The pressure from the factory is just an holding pressure that is put into the bladder when shipped. You will need to set up the system. That is why in post #4 I asked you what the design pressure was set for.

 

[jmtisme]

not sure what the design pressure is how would i find this out thank you again

 

[malcolmsanford]

Is it a danfos pump? The manufactures should give you the guidance on this.

 

[Marvo]

not sure what the design pressure is how would i find this out thank you again

Make and model number?

 

[telectrix]

my bladder starts to leak after 8 pints.

 

[jmtisme]

its a pair of pedrollo CP220A thank you

 

[malcolmsanford]

It's telling us the working pressure is 10bar how much are you putting into the pressure vessel. What is your pressure switch set at, cut in/out, and what are you trying to achieve with this pump.

 

[jmtisme]

the pumps feed a small temporay acc. set up with cold water (showers toilets etc) the pressure switch is set to cut in at 1 bar and out at 3 bar I have charged the pressure vessel to 2.5bar still got the same problem should there be a non return valve at the pipe feeding the accomadations after the pressure switch as I only have non return valves at the pump outlets.

 

[Marvo]

If you switch off the pump and isolate the incoming water supply and crack one of the fittings half a turn so there's no water pressure on the system does the pressure vessel maintain its 2.5 bar air pressure over time? 2.5 bar sounds a little high to me although it is is a very large capacity tank, we just charge the bladder to 1 bar usually and we use nitrogen.