I have an EcoPlus 633 water pump, and I wanted to know if it's possible to control it's output by adjusting it's speed somehow.

It's 120VAC but uses a magnetic drive as do all aquarium type pumps. Is it possible to adjust the speed of this style of motor by using PWM or some other method?

I just want to slow it down because it's output is too strong and would prefer to control it's output electrically, instead of using a valve and creating back pressure.

 

A recycle loop would be another solution, so that some of the pump's output would be diverted to a vicious cycle.

But I'd try one of two things: A simple lamp dimmer or a just a lightbulb in series with the pump.

A 35W bulb should knock the voltage to the pump in half. That might be too much. A higher wattage bulb will raise the pump voltage whereas a lower wattage will reduce it. A downside is that the pump will quit if the bulb goes out.

 

A recycle loop would be another solution, so that some of the pump's output would be diverted to a vicious cycle.

But I'd try one of two things: A simple lamp dimmer or a just a lightbulb in series with the pump.

A 35W bulb should knock the voltage to the pump in half. That might be too much. A higher wattage bulb will raise the pump voltage whereas a lower wattage will reduce it. A downside is that the pump will quit if the bulb goes out.

I was thinking of a recycle loop but my space is limited and the pump is plumbed in with very little room for modifications or adjustments.
Since I'm using 3/4" PVC, making a recycle loop would require more space in plumbing parts than the pump itself actually takes up.

The pump is also going to be pulling water through a filter so as the filter gets full the output will slow down. In the future I want to make a controller for all this stuff that will automatically increase the pumps output as the flow decreases.
So a solution to control the pump electrically would be best.

Would a regular light dimmer work on a mag drive motor? I have one lying around I can certainly try it.

 

It's worth a try, and I think it'll likely work. I think the term "mag drive" refers to the pump mechanism and not the motor. It's probably a pretty typical AC motor and many can be controlled fine with a dimmer.

 

light dimmer doesn't work, i just tried it and the water flow remains constant until the voltage gets too low and then it just stops.

 

It's worth a try, and I think it'll likely work. I think the term "mag drive" refers to the pump mechanism and not the motor. It's probably a pretty typical AC motor and many can be controlled fine with a dimmer.

Mag drive is a way to separate the impeller and motor.
the impeller is on a magnetic shaft, and the motor itself is just a big magnet. similar to a speaker and voice coil.
when you turn it on and there's no water in it, the impeller just vibrates back and forth.

 

Can you contact the manufacturer and request a solution? This was a trick we used before the internet.

What do you mean when you say magnetic shaft? Any photos? Is there any rotational movement, or does it just vibrate?

We need to know how it is electrically coupled, so that we can adjust it.

 

Ah ha..........these pumps are advertised as non adjustable flow pumps.

 

Output of those pumps can be controlled by a throttle valve
They're impedance-protected and water-cooled, so run happily with the output restricted

 

You are over-complicating a simple problem that the pump is already designed for. See post #9.

 

I'm not sure how to explain them exactly because it will sound like i'm explaining every other motor, but the motor part is nothing more than a magnet(s), this can be submerged completely in water because it's sealed. There is a hole in the middle where the impeller shaft slides into, this is just a shaft with a cylindrical magnet around it, and the actual impeller itself.
The impeller shaft slides into the hole in the housing and the impeller.


The impeller rotates just like any other pump impeller except when it's dry. if there is no water in the impeller housing then the impeller just moves back and forth instead of moving an entire 360 degrees.

It's the same way every aquarium powerhead works.

A light dimmer doesn't work though, and I don't have any form of 120VAC PWM device to try that.

 

You are over-complicating a simple problem that the pump is already designed for. See post #9.

See post #1, where I mentioned wanting to control it's speed automatically later on.
I doubt I can find an electric valve that will fit where I need it, or that would be cost effective.

All I'm trying to find out here is; can these pumps be speed controlled electrically, and if so, how?

 

can these pumps be speed controlled electrically,

No. You would be looking for a motor modulated water valve which is controlled by a pressure sensor to change the flow according to filter back-pressure. And this is not going to be cost effective. It won't save any on the electric bill, it will actually cost more electricity. You are going to have more than $100 and dozens of hours of labor in this to accomplish what you can do by changing/cleaning the filter regularly.

 

Ah ha..........these pumps are advertised as non adjustable flow pumps.

They make an adjustable flow model which has some form of built in valve.

No. You would be looking for a motor modulated water valve which is controlled by a pressure sensor to change the flow according to filter back-pressure. And this is not going to be cost effective. It won't save any on the electric bill, it will actually cost more electricity. You are going to have more than $100 and dozens of hours of labor in this to accomplish what you can do by changing/cleaning the filter regularly.

I love how you just jump in and shut everything down. you're adding in all this context that doesn't need to be there.
why does it matter how many dozens of hours of labour I put into a project I want to work on? I'm pretty sure that a motor modulated water valve is not the ONLY way to slow the pump down.

I want to build a controller for more than just this aspect, and the filter in question isn't even the main bio filter for the aquarium, it's a secondary filter for the accessory manifold so changing it regularly is fine, but it doesn't change the fact that I still want to be able to automatically increase the water flow as it slows down.

I'm not trying to save electricity, or cut back on my water bill, or whatever thing it is that you're ASSUMING I want to do.....
Let me make it simple, I want to do it simply and for no other reason than I WANT to do it.

 

Trouble is, some types of AC motors cannot be easily controlled because they rotate in sync with the 60Hz supply frequency. It sounds like this motor may be that type. There is such a thing as a VFD, variable frequency drive. They're expensive for big motors but maybe not for a 35W one.

 

I'm not trying to save electricity, or cut back on my water bill, or whatever thing it is that you're ASSUMING I want to do.....
Let me make it simple, I want to do it simply and for no other reason than I WANT to do it.

I just want to slow it down because it's output is too strong

That statement told everybody that you had a real, physical world reason to change the flow. Nobody assumed that those were your words. It's right here in black and white.

pretty sure that a motor modulated water valve is not the ONLY way to slow the pump down.

You already proved you can't modulate the motor with a dimmer, 3 other people have told you that you can't do that, but you still wanna do it, even if you must have a tantrum about it.

The next level is a variable frequency drive. You can get those for about $125 at retail prices.

And next time, don't pretend to a real need when you're really just self-stimulating.

 

There might be a start winding/capacitor circuit in the sealed stator. And it might not agree with a frequency other than it was designed for.

An autopsy might be required.

 

That statement told everybody that you had a real, physical world reason to change the flow. Nobody assumed that those were your words. It's right here in black and white.

You already proved you can't modulate the motor with a dimmer, 3 other people have told you that you can't do that, but you still wanna do it, even if you must have a tantrum about it.

The next level is a variable frequency drive. You can get those for about $125 at retail prices.

And next time, don't pretend to a real need when you're really just self-stimulating.

Sorry, yeah, you're right that isn't very clear.

There is a need to slow the flow rate. It's a ~600GPH rated pump. It'll lose a bunch of that through the plumbing it's hooked up to but will likely still be above the <250GPH that I actually need.

The want of it is adjusting the flow electrically/electronically. that's what I want to do "just because".

I'm already going to be using an arduino as a timer in the electrical box, and probably to display the current flow rate when I swap my manual flow meter for an electronic one, so I figured if I could incorporate automatic control of the pump output it would be a great bonus.

I don't want to continue using a dimmer because it doesn't work, we all agree. but a dimmer and motor speed controller are two different things, I'm not sure if a speed controller would have the same effect on this motor as a light dimmer does......but it most probably does.
PWM is a different matter, maybe it would work? that's what I'm asking but few people seem to know how these particular motors work so it's just a guessing game, that doesn't mean I'm asking how to make it work when it clearly won't.

I'm waiting on an email back from the company as to whether or not it's possible to control the output electrically, so I'll see what they say.

 

There might be a start winding/capacitor circuit in the sealed stator. And it might not agree with a frequency other than it was designed for.

An autopsy might be required.

I'm not going to tear one apart, I do believe they're potted so it would be the end of a perfectly good pump.

These things are pretty powerful though, you have to really pull to get the impeller out because the magnets are so strong, and when you're putting the impeller back in you can really hurt your fingers if you're not careful because it'll pull the impeller back in with enough force to pinch your fingers between the blades and pump housing.

I've been having a really hard time finding a simple cutaway diagram of one of these style of pumps

 

but a dimmer and motor speed controller are two different things, I'm not sure if a speed controller would have the same effect on this motor as a light dimmer does......but it most probably does.

Not if we're talking about a VFD. That's completely different than a dimmer (which is a triac-based circuit).

PWM is a different matter, maybe it would work?

I don't think so. It works with a lot of DC motors but not likely you AC motor. It's possible you could make a sort of square wave inverter, and vary the frequency of the pulses (not the duty cycle, as in PWM). In other words you could make a DIY VFD.