Restricting pump lowers power consumption?

[CalmSeasQuest]

ALL centrifugal pumps can be restricted on the dischare side without harming the pump and it WILL reduce the power consumption. This only applies to centrifugal pumps and most all aquarium water pumps are centrifugal pumps.

Its hard to grasp but read up on Bernoulli's Theory and The Laws of Affinity. Basically what it is is that by restricting the flow you are reducing the amount of work being performed thus reducing the power consumed. It also usually reduces the corresponding heat the pump produces since heat is directly tied to power consumption.

Great explanation AZD. I would add that although there may be some reduction in heat when throttling the discharge, there is also a corresponding loss in cooling flow. IME, the loss of cooling is greater than the heat reduction and when restricted more than a token amount (my pure guess is ~20%), results in the pump running warmer. A great example of this is the use of MJ1200s in powering media reactors. As they are often restricted to optimize the flow through the reactor - the loss of flow (cooling) results in the impeller and shaft running warmer and can dramatically increase the amount and rate of calcium build-up and result in increased maintenance. Another option is to by-pass some of the discharge water back to the sump. Although you don't gain the energy reduction, the pump runs cooler.

I'm waiting on a water blaster myself that's what's tarted this thread lol

I mentioned the above cooling issue as I've been running a WaterBlaster HY7000 for about the past year as my return pump and have had problems with it seizing about every 6 weeks due to calcium deposits in the bushing. I currently have it restricted about 30%, but am going to work on a bypass too see if it extends the time between tear-downs and cleanings.

 

[Netta Fish]

Great explanation AZD. I would add that although there may be some reduction in heat when throttling the discharge, there is also a corresponding loss in cooling flow. IME, the loss of cooling is greater than the heat reduction and when restricted more than a token amount (my pure guess is ~20%), results in the pump running warmer. A great example of this is the use of MJ1200s in powering media reactors. As they are often restricted to optimize the flow through the reactor - the loss of flow (cooling) results in the impeller and shaft running warmer and can dramatically increase the amount and rate of calcium build-up and result in increased maintenance. Another option is to by-pass some of the discharge water back to the sump. Although you don't gain the energy reduction, the pump runs cooler.


I mentioned the above cooling issue as I've been running a WaterBlaster HY7000 for about the past year as my return pump and have had problems with it seizing about every 6 weeks due to calcium deposits in the bushing. I currently have it restricted about 30%, but am going to work on a bypass too see if it extends the time between tear-downs and cleanings.

Wow thanks for the info on the pump. That's the first I have heard of that I'm waiting on he 5000 for my 120 and 2 reactors and I will have a bypass in there the only reason I started this thread was to find out how power was saved lol

How is the pump other wise? Run noisy or hot?

Thanks

 

[CalmSeasQuest]

Wow thanks for the info on the pump. That's the first I have heard of that I'm waiting on he 5000 for my 120 and 2 reactors and I will have a bypass in there the only reason I started this thread was to find out how power was saved lol

How is the pump other wise? Run noisy or hot?

Thanks

Other than the seizing issue (which I hope to be able to resolve) I like the pump. It's quiet and runs cool.

 

[richardb]

i never had any problem with the one i did and as far as i know it may still be working to this day i sold it to a friend of mine for his water fall lol but if you think about it there should be no damage done your reducing the electrical consumption and while doing that reducing the amount of water the pump can move..the way i looked at it i was by reducing the wattage/voltage its no different than changing the current pump from a 1400gph at 240v to 700 gph at 120v if you were to turn the dial half way down (theory) but the problem by doing that is it takes 240v to turn the magnet that turns the prop but as long as you dont drop below the thresh hold, then it want stop pumping because gravity is assisting the pump prop so its a hit and and miss but it worked for me i can not promise it will work for you as it did for me

 

[peacetypes6]

this is no bueno

 

[VegasRick]

Other than the seizing issue (which I hope to be able to resolve) I like the pump. It's quiet and runs cool.

How is that going to be resolved? I have the same issue and finally pulled it and replaced it with a reeflo. It always seemed to stop at the worst possible time too, like when I am out of town

 

[CalmSeasQuest]

How is that going to be resolved? I have the same issue and finally pulled it and replaced it with a reeflo. It always seemed to stop at the worst possible time too, like when I am out of town

I've heard from quite a few others that are having the same problem. In my case, I'm hoping that my issue is related to the fact I've got it throttled back about ~30%. If I can't resolve it, I'll also be swapping it out for another pump.

 

[VegasRick]

I noticed on a couple of the small pumps, Tunze and another I can remember off hand that they have built into them the ability to restrict the flow on the intake side to regulate the output.

 

[garage1217]

Azdesertrat, so this is where ya went haha. Long time no talk. On this series of pumps, I have...
- bb5000
- wb5000
- wb2000

All running in my current system. I have also owned and reviewed an bb7000. They are stellar pumps and you will like them. I have had my wb5000 for close to 2 years / since introduction. I was one of the very first to get one. My bb5000 and wb2000 have been in use for about 6 months. All are and have performed flawless.

 

[AZDesertRat]

Hey!
Good to see you.
I split my time between here, 3Reef, Nano-Reef, The Reef Tank and AZReefs.
I'm thinking I will try the WB 5000 to replace my OR3500 for a little more flow at about the same power consumption. My conservation efforst have really paid off, I have cut over $1400 off my power in the last calendar year versus the previous years and I'm going to continue looking for more efficient pieces of equipment.

 

[garage1217]

Right on! I did the same, not sure if you ever saw my big efficiency post on RC. My highest bill prior to my cutting was over $460ish, my peak bill this year... $240 and that with an aquarium over double the size of my previous. Need to update that post. Lowest bill with the new tank, $134 this year month before last :tongue:

You will like the WB pump, love all of mine.

 

[AZDesertRat]

My highest before was over $380, this summer it was $241 and the lowest has dropped from $164 down to $119. I am hoping to see a bill under $100 in February or March.
I followed along and have been doing a running thread on AZ Reefs myself.