AC and DC pumps.... not as different as you may think.

[mcarroll]

I would agree that small powerheads probably don't have much of an issue because of the low power.

You are not wrong – I think controllable powerheads do have a shorter lifespan than comparably sized AC powerheads.

 

[mcarroll]

More current does dictate thicker wires, but I'm not sure this drives much cost. The copper weight in these pumps is very small and copper wire costs under $6/pound. The difference in copper costs would be marginal compared to the other costs.

You're right I was being literal, but there is more than one way for thicker copper to be "expensive". Extra material takes up space in the design!

Maybe that's not quite significant either, but it's a thought. I know there's no such thing as a free lunch...sometimes it's just a little mysterious who's paying!

 

[Alfrareef]

It's pretty simple and the engines aren't so similar as you may think.

AC are better, more powerful and efficient but I takes more technology (money) to control like the DC. Also it cost more to build a smaller AC versus a DC.
If you want to go deeper just look at the wave (electrical) a AC engine causes when starts and then imagine what happens when you start trying to start-stop-reverse a engine like that.
Lifespan it's always related with quality of the materials, build, use and environment. Every time I look at my Jebao turning back and forward I think of when something it's going to broke and I'm sure it will not be the DC engine the first to fail.

 

[ksed]

It's pretty simple and the engines aren't so similar as you may think.

AC are better, more powerful and efficient but I takes more technology (money) to control like the DC. Also it cost more to build a smaller AC versus a DC.
If you want to go deeper just look at the wave (electrical) a AC engine causes when starts and then imagine what happens when you start trying to start-stop-reverse a engine like that.
Lifespan it's always related with quality of the materials, build, use and environment. Every time I look at my Jebao turning back and forward I think of when something it's going to broke and I'm sure it will not be the DC engine the first to fail.

Perhaps I may have misunderstood.
Are you saying that the engine is fine but the electronics are weak?

 

[Alfrareef]

Not really. What I fear are the caskets, shaft,propeller. The electronics should be ok if it doesn't "burns" the first days.

 

[guobinfu]

Thanks ! fantastic!

 

[Brew12]

Thanks ! fantastic!

Glad you liked it!

 

[saltyfilmfolks]

I don't really like DC pumps for the reasons stated. They don't last very long. A couple of years won't do it in my tank as most of my AC pumps ran 15 or 20 years with no problems or even maintenance but I have a box filled with DC pumps that croaked in less than a year. I don't care what I pay for a pump, but I want to start it, then not look at it until 2030.
I also see no reason to adjust the speed of a pump. I buy it for the power I need and let it run.

This guy ran continuously for 20 or 30 years. Maybe longer


This little gem ran my skimmer for probably 20 years and I never opened it. It is still running fine.


This thing died in 2 years. I also have a box of these


Of course I also still have this projector that also runs perfectly. For you youngsters, this was the cell phone video machine of the fiftees. (I Phone - 57)

I have a few of those projectors.

And more than a few broken pumps.

 

[Jemm]

If I fed my ac pump from a dc controller, would it run quieter?

Or is there a differance in poles in the stator

 

[Brew12]

If I fed my ac pump from a dc controller, would it run quieter?

Or is there a differance in poles in the stator

Probably not. I suspect it wouldn't work well at all. The motor design needs to match the controller output.

 

[Paul B]

Brew, Excellent article. I have been a Journeyman electrician for fifty years and I did a lot of work with motors. Very large motors but I had to look up reluctance motor. I found out why I never encountered them in the trade. They just came out this century and I retired at the end of the last century.


I know how they work but the electronics, like most electronics from China is very cheaply made so they croak.
It's like LEDs. They are always touted to last 25 years but the truth is they don't last as long as a cheap tungsten bulb that Thomas Edison invented 120 years ago.

The LED part lasts forever but the electronics burn up.

I have one of those DC motors on my tank for about a year so I expect it to go on fire soon.