How to slow down fish pond pump

[portisheaddan]

Hello everyone in here. I am new to the forum so saying hi!

I am after some advice regarding an electrical garden fish pond pump.

I have bought a pump that is quite honestly to big for my pond. Its pumping too way to fast - twice the speed i need. Although I have a knob on the side that I can turn to restrict the output, this wont slow the pump down and will still consume too much electricity.

My question is - Although the pump is sealed - Is there a component/components I could get at say maplins etc that I could solder or put in line to reduce the power or voltage to the pump ?????

Make any sense?

Is there any way or doing this? It has to be cheapish other wise I may as well buy a new pump.

Thanks everyone

dan

 

[rocker]

Does the pump plug in stroight to a plug socket, or does it connect to transformer somewhere?

 

[portisheaddan]

Mains cable wired to a plug to 240v socket at the moment. (No transformer) Surely I can slow it down electrically some how or surpress the ingoing power ?

 

[Pat Tester]

Depending on the pump design you may find attempting to run it slower will make it much less efficient as a pump. Running it from a dimmer if it works will just covert the unused power into heat, and I don’t know of any IP rated dimmers.

If I was you, unless the pump is above 600W would bleed some of the output (water) back into the input side of the pump, this will reduce the pressure and
volume of the output and leave the pump running as it was designed to do.

 

[nickblake]

Simple get a tap for the outlet you can get them from all good pet shops .... think i sounded like an ad then all you do is the adjust the tape for the flow you require just like the tap in your house as for the electrical consumption they are about 35 watts so consumption will be fairly low

 

[portisheaddan]

Well it has 2 outlets. One on top for a fountain which I have closed as I dont want it and the outlet for the filter. They are both adjustable and closable. Its just too powerful so I have to have the filter outlet closed right down to slow the flow up. I just thought its a waste of electric now. Its says its 70watts.

Maybe ill sell it.

Does that cost a lot to run per day? Guess I could turn it off over night ,

 

[UNG]

A 70w pump is going to use about 1.8 - 2 Kw per day at the moment 1 KwH costs about 16p so it's about 30 - 32p per day to run

 

[Knobhead]

Restricting the output flow will reduce the loading on the motor. This method is use for most large industrial pumps. Most of them you'd never get started otherwise.

 

[portisheaddan]

Restricting the output flow will reduce the loading on the motor. This method is use for most large industrial pumps. Most of them you'd never get started otherwise.

So if I close the manual valve further so it pushes out less water, the pump will cost less to run?

Is it not the case that closing the valve would made the motor work harder because its trying to push the same water through a smaller hole but cant do it?

Or have I missed the point.

 

[ian.settle1]

So if I close the manual valve further so it pushes out less water, the pump will cost less to run?

Is it not the case that closing the valve would made the motor work harder because its trying to push the same water through a smaller hole but cant do it?

Or have I missed the point.

You are correct in the end the pump will burn out

 

[Izzy's Dad]

And if you undervolt the motor it'll stall and kill it's self!

 

[Graeme Harrold]

All depends on the pump type. Most of these should be of the centrifugal vane type rather than a fixed stroke and will run OK with the output restricted. DO NOT try restricting the inlet as it will cause the pump to cavitate and kill the pump quickly....

 

[SirKit Breaker]

You are correct in the end the pump will burn out

At least it wont catch fire if its in a pond or whatever sorry couldnt resist my gross stupidity

 

[Knobhead]

Large centrifugal pumps or fans used in industry have valves or dampers to control flow. If you close the valve the loading on the motor goes down. As Graeme Harrold said don’t restrict the inlet for a pump, as the pump will cavitate causing high vibration. Most drives would not start without some restriction on the flow.

Large or small the effect is the same, lowering the flow lowers the loading

 

[EasT]

A lot of pond pumps these days work on magnetic induction (I think that's the term. A the pump windings are producing a magnetic current in these cases, and the impeller is fixed to a freewheeling impeller I can't imagine these type burning out. Mind I no very little about electrics.

 

[Graeme Harrold]

What you describe is a "brushless motor" ...... usually very reliable bits of kit

 

[EasT]

What you describe is a "brushless motor" ...... usually very reliable bits of kit

mine has been in use 24 hours a day for 19 years. because I don't use a pre-filter but pump unobstructed to my filtration system it does pick up grit etc. I have replaced the impeller 4 times. I bought 6 replacements with the pump as I know how reliable they are.

I can't imagine that throttling the flow back on one of these back would be any problem.

 

[ian.settle1]

At least it wont catch fire if its in a pond or whatever sorry couldnt resist my gross stupidity

Forgive you as you do come from Yorkshire