Backyard Aquaponics
A place to discuss aquaponics

any updates on the brushless pumps?

It is a brushed pump, and it is still working.

Matt,

Mine was shipped last week but hasn't arrived yet.

They claim 30,000 hours continuous use, which should mean over 13 years at 15 on, 45 off. For about the same price as a brushed pump that sounds like a good deal to me.

Anything would be better than those bilge pumps.

Cool - From further reading it sounds like they have a magnetic coupling between the motor and pump (so no need for a seal) and the centrifugal pump has pretty tight tolerances. I'm surprised how little there is on the web on these brushless dc motors - the specs look very promising.

It'll be interesting to see how it goes with pumping solids (with tight tolerances in the pump). I wonder if switching on and off will help keep it free with some backwash though not sure whether the pump will run backwards to allow a good backwash flow when de-energised with a head of water above it. If solids are a problem, it may be best to run it in a CHIFT PIST type setup so that it does not have to pump fish solids - just clean GB water.

How are you planning to switch yours on and off?

Same as always -- with a homebrew solar powered 12V controller based on an AtMega16.

More info in the solar link in my signature


Interesting what you said about backwash, I'd never considered switching on and off to be beneficial, but I can see that a bit of backwash would be quite good if there was a blockage.

From the pumps that I've looked at previously, there's quite a good chance that when you switch them off the water will backwash -- I'm pretty sure that the motor doesn't need to spin backwards either. Pretty much all centrifugal pumps will be the same, they're a long way from watertight when you stop the impellor.

and there was me thinking some 555's and a few resistors and capacitors! Looks like quite a flexible beast - like the A/D specs!

Well the 12V brushless pump arrived last week, so I installed it today.

There is quite a large gap between the impellor and its housing, it's as if the impellor is half as thick as it should be. There would be no worries about backflow with this model, once the impellor stops moving the water in the system will backwash with no problems whatsoever.

Despite my misgivings, when I hooked it up it seemed to pump quite well, at about the same rate as the old brushed blueline pump, matching its specs. I guess the proof is in the amount of time it keeps on trucking for... no quick answers on this one.

Good to hear it works well - If it makes it past a few months it will be on top of plenty of bilge pumps!

I have purchased three brushless DC pumps (the "cheap" 24V ebay version - 2500l/h) for four months now. One of the three died within two weeks and the autopsy suggested that it may be due to clogging.

I have since been cleaning the other two diligently and they are still running four month later.


The future will tell!

were/are you pumping solids with yours Gabe? I plan to use mine in the sump tank so it should have minimal solids pumping duty.

Hi Mattyoga

Yes i am pumping solids. Reducing the solids is likely to improve the pumps life - that's why i try to clean them daily at the moment (which is a bit of a chore).



Gabe

Installed my backup DC pump this weekend - its an ebay special with these 'specs'
Description
Features:

Super long working life(more than 30000 hours)
Adopt high performance ceramic shaft
The axis is enclosed with static sealing, not dynamic, which can avoid leaking problems
Amphibious design
Submersible installation and entirely waterproof
low consumption
low noise(less than35db)
Can be used in many fields, such as computer cooling system, Garden fountain, Aquarium, car cooling system, humidifier, air conditioner, and many other cooling and circulation systems.
Specifications:

Sizes and weight: 85.5x82x48; 250g
Dimension of inlet: 20mm(1/2 inch thread)
Dimension of outlet: 20mm(1/2 inch thread)
Driving method: Brushless, Magnetic , 2 phase
Pump material: PA66
Condition of use: Continuously
Fluids: Water, oil, gasoline, acid and alkali solution etc
Max working temperature: 60 ℃
Power consumption: 13.2W
Rated voltage: 12Vdc
Voltage used: 12Vdc
Max rated current: 1.1A
Max flow rate: 840L/H
Max Static Head: 3.0m(9.7ft)
Noise: <35dB
Water proof class: IP68(can be submersible installed)
Life span: More than 30000hrs
Power supply:Solar panel; DC electric source; battery

Put an Ammeter on it - was drawing about 1.5A rather than 1.1A. Sounds pretty noisy so will see how long it lasts. Its supplied from a car battery with a battery charger hooked up to it so has about 13.8V on it rather than 12. Here's the head curve - have not measured how much water it pumps - might try and see hpw long it takes to fill a bucket.... Flow did not change much when moving from surface of water to 0.5m higher (where GB is). Estimate power is closer to 20W. Might put a dc timer in to reduce power to 50% - Should be able to get away with putting a 1A charger on the battery then as well. Battery is 110AH so should get a good day of backup out of it

My brushless pumps have now been going for ~ 6 months. They clog easily and i clean them every 2'nd day.

They are rather energy intensive - 2.5kl/h at 75W.

Fortunately they are fueled with sun power!

Are they a similar design to the one above Gabe? Just wondering how to clean it - not sure if undoing the screws will break a seal... I've located mine in the middle of the water column and put one of those big black filter sponges around the inlet so hopefully it should stay clean - as its only a backup I don't need it to move solids.

Mine has been running on and off for almost 2 years now and I never had to clean it out. It is not brushless, but I like it. Not sure how many hours are on it, but a good bit.