Pump won't prime -

[DekDaeng]

I have a 'Forerun' brand 550 watt pump, which just refuses to prime. In spite supposedly being able to provide 8 m suction, even if I prime it with 8 m head! (i.e. from the top of my 3 story shophouse) it still refuses to pump! I have had it working intermittently, (from a large bucket)  but when I place it 'in line' - it just sits and spins - as you can see in the vid. Previous pump was a 250 watt fujika, which had ok performance, so 550 SHOULD be great for my place & roof garden  

 

Grateful for any suggestions -

 

Thanks,

Deks

\

[cornishcarlos]

6 minutes ago, DekDaeng said:

even if I prime it with 8 m head!

 

Maybe there is a one way valve on your pump outlet side  ??

You need to ensure there is no air in the suction side and no possible way for air to enter whilst running. (that large screw connection would be a good starting point)

[bankruatsteve]

Is there valve on the pump input side and is it open?  I couldn't play your video but if you're just pumping air, that's usually the cause.

[Crossy]

Are you actually getting prime into the suction tube?

 

Foot valve on the suction OK?

 

Our one fairly long suction has a blanking cap on a T, fill it with water from the hose, an awful lot of air in those pipes to come bubbling out.

 

[gaztop08]

I couldn’t get your vid to play either on my iPad.Maybe you could try putting vid on YouTube and putting link here if you still have problem.

[farmerjo]

Highly unlikely but you checked motor rotation.

[DekDaeng]

Have found a temp solution - connected to town water, with positive pressure at intake,  pump will start pumping, with a good output. But neither orig or new pump will start, w/o.

???

 

Thanks for  your suggestions -

[Crossy]

Is the foot valve serviceable / obstructed (not closing)?

 

Possible air leak on the suction side?

[farmerjo]

 

Edit Is it the MKP 60-1 model

[farmerjo]

40 minutes ago, farmerjo said:

 

Edit Is it the MKP 60-1 model

https://wpscr.com/index.php/productos/sistemas-de-bombeo/bombas-horizontales?format=raw&task=download&fid=221

[DekDaeng]

On 3/5/2020 at 4:14 PM, Crossy said:

Is the foot valve serviceable / obstructed (not closing)?

 

Possible air leak on the suction side?

I put a new foot valve on - it leaks a little. May make a new one with a softer silicon o ring to seal.   

 

But I can fully prime, at top of well riser, and at pump inlet. Still, it will not start pumping. Have found a temp soln, connect to neighbours town supply during the night (when town pressure is ok - then pump pumps well, 30 min I can pump enough for the garden etc for next 24 hours, saved in big rice storage bins. Much better than carrying it up!

 

Well water level is pump -6M; drought might be part of the problem Anybody got an ETA on the wet season?

[DekDaeng]

On 3/14/2020 at 4:35 PM, DekDaeng said:

I put a new foot valve on - it leaks a little. May make a new one with a softer silicon o ring to seal.   

 

But I can fully prime, at top of well riser, and at pump inlet. Still, it will not start pumping. Have found a temp soln, connect to neighbours town supply during the night (when town pressure is ok - then pump pumps well, 30 min I can pump enough for the garden etc for next 24 hours, saved in big rice storage bins. Much better than carrying it up!

 

Well water level is pump -6M; drought might be part of the problem Anybody got an ETA on the wet season?

Right, Crossy. An old slip joint at top of well decided to start leaking. Had not moved or changed in ~ 15 years, so did not suspect it.

 

Gold standard leak test is air pressure test. Prime full circuit with water, then inject air @  40psi. You will find all leaks in seconds. Actually only leaks on suction side matter - leaks on the output / pressure side find themselves : - )

 

If you haven't got a compressor, you may be able to bleed air off a spare tyre to pressurise circuit.

 

Chok dee.

 

 

 

[Led Lolly Yellow Lolly]

Are you sure polarity is in order? I had a headache with a pump recently. Someone had fiddled around with the start capacitor and it was running backwards.

[bankruatsteve]

2 minutes ago, NilSS said:

Are you sure polarity is in order? I had a headache with a pump recently. Someone had fiddled around with the start capacitor and it was running backwards.

Uhm... capacitors are non-polar.  

[Led Lolly Yellow Lolly]

Ahem, well some have polarity, ahem. but I know that, yet on some pump designs the wiring configuration will cause the pump to run backwards. This is suspect to be the problem for the OP.

 

 

 

[Mama Noodle]

Just now, NilSS said:

I know that but on some pump designs the wiring configuration will cause the pump to run backwards

 

You're thinking about DC motors

[Mama Noodle]

On 3/1/2020 at 2:24 PM, DekDaeng said:

I have a 'Forerun' brand 550 watt pump, which just refuses to prime. In spite supposedly being able to provide 8 m suction, even if I prime it with 8 m head! (i.e. from the top of my 3 story shophouse) it still refuses to pump! I have had it working intermittently, (from a large bucket)  but when I place it 'in line' - it just sits and spins - as you can see in the vid. Previous pump was a 250 watt fujika, which had ok performance, so 550 SHOULD be great for my place & roof garden  

 

So this pump is supposed to pump from somewhere (a well?) UP 3 stories? 

 

Suck water from 8m down and push it up 3 stories? 

[Led Lolly Yellow Lolly]

Quote

You're thinking about DC motors

Excuse me but switching the starter winding leads on a single phase AC motor will cause it to run in reverse. I know what I'm talking about.

 

 

 

 

[Mama Noodle]

2 minutes ago, NilSS said:

Excuse me but switching the starter winding leads will cause a single phase AC motor to run in reverse. I know what I'm talking about.

[Led Lolly Yellow Lolly]

[Crossy]

Everyone may wish to read  post #12 where the problem and solution was described

 

[sometimewoodworker]

4 hours ago, bankruatsteve said:

Uhm... capacitors are non-polar.  

Electrostatic capacitors are nonpolar, meaning they can be connected in any direction of polarity, and there is no difference. Electrolytic capacitors are polar by nature, they can be entertaining, through shocking to deadly if reversed and a substantial charge is applied.