Author Topic: Solar Water Transfer Pump  (Read 9085 times)

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Offline OTG

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Solar Water Transfer Pump
« on: August 17, 2018, 11:05:16 pm »
I need to transfer bore water (from a tank) over some distance (up-to 600m) and height (30 to 60m Total Dynamic Head), depending which other tank/watering points I send the water to.

The pumping rate/flow isn't of great concern, but I do want as reliable a pump as possible and it needs to be DC/Solar. I've found the below two examples which seem to meet my needs.

Sorry, my links got a "CleanTalk ***Forbidden. Contains Contacts" error when posting - search for either of these numbers on aliexpress.com instead:

32802958030
32793093231

Just wondering what others think:
  • Which is likely to be more reliable in the long run - a Jet Pump or a Multistage pump (I'm no expert on the merits of the different type of pumps - I don't think a straight-up single impeller Centrifugal will handle this head, or at least I've not found one that can)?
  • Anybody out there with experiences or advice they can share reagarding DC/Solar transfer pumps?
  • Any personal recommendations for one pump or another (on my list or otherwise)?

Thanks Y'all!

Offline rossw

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Re: Solar Water Transfer Pump
« Reply #1 on: August 18, 2018, 04:58:34 am »
OK, from my experience....

DON'T even consider any pump that uses a brushed DC motor. Even very expensive, name-brand ones like shurflo.

I WOULD NOT ever consider a positive-displacement pump again. They have all sorts of on-paper benefits, but reliability and maintenance are not there in the long term.

I ended up ditching the DC pump and using an inverter + AC induction motor multistage bore pump. Not only was it cheaper, but it was better made, has basically no wearing parts (brushes etc), moves more water, operates at a higher efficiency and has given faultless operation in identical conditions, so far for 4 times longer than the DC pump, but who knows how much longer.


Offline oztules

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Re: Solar Water Transfer Pump
« Reply #2 on: August 19, 2018, 02:40:57 am »
Well that just goes to show how we all get different results.

On this island we use extensively the brushless DC solar bore pumps.... and thats what I would recommend here.

Your 60meter head means roughly 90 psi of pressure. A centrifugal pump will be a very inefficient performer in this instance unless it has a lot of stages... maybe 10 or more for a bore pump diameter. ( 100mm)

For the JCM-5.0-80, it would do the job, but it is a 1hp multi stage pump, so it should too... but with little room to spare.

The jets series JETS -4.2-60  won't do any good, as your max pressure is equal to their max pressure... so no flow worth speaking of.

A progressive displacement cavity pump ( screw pump) is what we would use here ( and do for 120psi dam filling applications), as the centrifugal ones are too "loose" unless your in the 10 stage style... then they are pretty tight, and will pump in poorish light as well.

I would resist the inverter idea, unless your going to pump it all at once, fast and short, then spend the rest of the day recovering... depends on the duty cycle

In closing, we do this thing over here. Progressive cavity is the best for solar and high pressure.
Brushless only.... not AC but DC ( BLDC to be exact)... they both run inverters I know, but the DC three phase type is more versatile with differing cloud formations, and low down torque with poor light.... and NO batteries.

We use one of the pumps out in the ocean for seawater pickup for the reverse osmosis unit out on one of the outer islands, and they work ok there too.... sand and sediment aside.... but they handle that too.

 For medium pressure and high flow rate, the multi fan centrifugal ones are fine. For high pressure ( over 100psi ) the bore pump style seems the best fit... just throw it into the tank and your good to go.

All the little DC brush pumps of either the diaphragm or impeller type are best left on the shelf as Ross has forcast.

Thats my take on it anyway.


.........oztules

Flinders Island...... Australia

Offline rossw

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Re: Solar Water Transfer Pump
« Reply #3 on: August 19, 2018, 06:43:44 am »
the brushless DC solar bore pumps

Brushless (ie, ECM) motors would be fine - but when I was last in the market, they were not available, or not at any sane price, from anyone I could get to talk to about them. Nowdays they'd probably be a good deal.

(In my specific instance, there's no power near the pump, I have to run it some 400 metres from the house. A 750 watt pump on DC would require either disturbing voltage, or much heavier wire).

Quote
Your 60meter head means roughly 90 psi of pressure. A centrifugal pump will be a very inefficient performer in this instance unless it has a lot of stages... maybe 10 or more for a bore pump diameter. ( 100mm)

I think mine is 4 or 6 stage, in a pump designed to fit down a 4" casing.

I have 60m vertical, and 400m of 40mm poly pipe, plus a non-return valve at the bottom that's worth a few more PSI.
Here's the water coming into the top tank - this is a 1.5" fitting the water is coming out of.


Quote
A progressive displacement cavity pump ( screw pump) is what we would use here
The diaphram and reed valves type positive displacement pumps are nothing but trouble, IMHO. Screws probably far better, but again - depends on what's available at the time!

Quote
I would resist the inverter idea, unless your going to pump it all at once, fast and short, then spend the rest of the day recovering... depends on the duty cycle

That's exactly what I do. I was sick and tired of running a low capacity pump that trickled water in like a leaky dunny and had to run 24/7 for weeks at a time to do anything. Now I run the new pump each afternoon for a week, fill up the top tank, then don't touch it for months :)

Quote
DC ( BLDC to be exact)... they both run inverters I know, but the DC three phase type is more versatile with differing cloud formations, and low down torque with poor light.... and NO batteries.

Absolutely, and that I'd agree with. I didn't catch the reference to brushless in earlier posts, which is why I piped up.


Quote
For medium pressure and high flow rate, the multi fan centrifugal ones are fine. For high pressure ( over 100psi ) the bore pump style seems the best fit... just throw it into the tank and your good to go.

Only warning with this (and it was my local pump expert friend who put me onto this one) - bore pumps expect (nay, require) water flow over them to keep them cool. Doing what I had intended to, and dropping a bore pump into a large tank and expecting it to work is an early death sentence for them. He STRONGLY advised me to make a cowel for the pump to give it the environment it expects. A lump of 4" pipe around it, capped off at the top, down the pump almost to the bottom of the motor.

Quote
All the little DC brush pumps of either the diaphragm or impeller type are best left on the shelf as Ross has forcast.
Thats my take on it anyway.

Reckon I'm with you on this one mate!

Offline OTG

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Re: Solar Water Transfer Pump
« Reply #4 on: August 20, 2018, 08:31:27 pm »
Jeez Ross, what did a positive displacement pump ever do to you!?  ;)

Seriously though, I can imagine Reciprocating type pumps would be a pain to maintain and probably not last that long. I'm not familiar with all Rotary type pumps, but if anything, I'm amazed by the simplicity of a screw pumps worm impeller and the ease with which they can be replaced (cheaply too). Most screw bore pumps even come with a spare impeller - not sure what this says about longevity though? Whats your experience been OZ? My bore pump is a 36V 1.8-90 screw pump (similar to item 32417332198 on AliExpress.com), it's coming up to a year and still going strong...

As covered in another topic - http://www.anotherpower.com/board/index.php?topic=1244.msg14456#msg14456, I was going A/C, but due to sudden/unforseen circumstances, I have switched and committed (rather happily I might add) to a DC path. Though, a 400m run of 3 core is impressive ross, you must have a good trench shovel/back!   ;D

To be honest, I'd never thought of just chucking another bore pump in the tank - I could even use the same panels, controller, etc as my existing bore (just switch the pumps using a 4 pole DC isolator - and keep one controller as a backup)! Say I did just get another 1.8-90 pump, yes it could handle the head, but what about the distances? What size pipe would you use (I'm using 11/4" for the bore - was figuring the same for the transfer pump)? And would T'eed off lines to various tanks affect it at all (my intent would be to have all branches closed, with only the line/tank that needs filling open)?

Finally, you're right about keeping them cool Ross - Pictured is my DIY shroud for my bore (mostly to keep pebbles out - they bloody killed my last pump), but I would definately make another if using a bore pump in the tank.
7729-0

PS: And yes, we're all agreed that brush pumps are best avoided!

Offline rossw

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Re: Solar Water Transfer Pump
« Reply #5 on: August 20, 2018, 11:48:16 pm »
Jeez Ross, what did a positive displacement pump ever do to you!?  ;)

Apart from the obvious (letting me down!) ??    :)


Quote
Though, a 400m run of 3 core is impressive ross, you must have a good trench shovel/back!   ;D

I ran a 40mm pipe (1 1/4"), plus conduit with 2 x 10mm power cables, a suitable earth and I think 3 x 2.5mm for controls if I ever wanted them later). Digging that trench in this terrain by hand wasn't happening!



Offline OTG

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Re: Solar Water Transfer Pump
« Reply #6 on: August 27, 2018, 07:33:52 pm »
Well, I decided to go the bore pump route and picked up another 24V 210W solar screw pump - Item 32417332198 on aliexpress.com. You're a very persuasive bloke Oz!  ;D

As noted, this way I can use the existing panels (or panel - it's just 1 x 320W Jinko) and controller, plus I can swap parts on these pumps and now have a spare/backup controller to boot - easy!

The trick now is finding a way to switch between the two pumps...

I could be lazy and simply wire in two 3 Pole DC Breakers - but the cost of this ( 2 x 4pole or 1 x 6pole enclosure/breakers) quickly adds up, it's a bit messy, I don't really have the space for it, and with the better half running the pumps now and then I want it to be as simple as possible.

So after a bit of digging on the google machine I found this -
https://au.rs-online.com/web/p/non-fused-switch-disconnectors/3307792/
https://docs-apac.rs-online.com/webdocs/134b/0900766b8134ba75.pdf

A 3 Pole/3 Position rotary switch, rated for 10A @ 24V DC (210W Pump Motor @ 24V = 8.75A), I won't be switching under load so that shouldn't be an issue (will turn the controller on/of & flip the solar panel breaker on/off when switching pumps), it's IP65 surface mount, will fit nicely where the solar cable is currently coiled up (in the picture - I'm yet to run conduit with proper MC4's - I needed the water with the drought and all :) ), and it's $65 from RS Online. I'm just clarifying the contact sequence with RS to be sure it suits - I believe it'll be 1 x Open Common State & 2 x Closed States (per my scrappy drawing).

Whaddaya'll think - do the job? I'd be happy to hear any thoughts, suggestions or alternative switching ideas.

Offline rossw

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Re: Solar Water Transfer Pump
« Reply #7 on: August 27, 2018, 08:03:11 pm »
Looks like a winner to me.

The "Contact sequence" in the PDF for that switch shows it as six discrete SPST contact pairs, with jumpers between two to make change-over contacts.

(Eg, in position 1, contacts 1-2 are joined, in position 2 contacts 3-4 are joined, and the jumper from 2-4 makes you a change-over with 1/2/3 where contact 1-2 is closed in position 1, and contact 2-3 is closed in position 2.

All switches are indicated off/open in the centre-off position, so this will do your application nicely.

It would also be easy to rewire it as a reversing switch for a 3-phase application - so a handy switch to have.

Offline OTG

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Re: Solar Water Transfer Pump
« Reply #8 on: September 06, 2018, 01:41:23 am »
Quote
Looks like a winner to me.
I thought so too. And your contacts explanation makes sense and was a good help, thanks! Good point re 3-phase.

Funny story - When I mentioned clarifying with RS, I meant Eaton... after a brief chat with the sales guy, his advice was (paraphrasing) - I can't advise on a switch because your products/devices aren't Eaton and our switches haven't been tested with them... ??? After an awkward silence, I noted that Eaton don't make every kind of electrickery product/device and there's no way they have tested every possible mix of components either... to which he promptly replied (again paraphrasing) - I know, but that's what we've been told to say!  ???...  ::)... Anyways, after suggesting we ignore my specific devices for a moment and just focus on the circuit design/parameters, he did come up with some suggestions and agreed this switch was best.

In the end however, I ended up going the next model up - https://au.rs-online.com/web/p/non-fused-switch-disconnectors/3307809/

Bigger knockouts (M25 vs M20) bottom AND top (the 3G 2.5 power + level sensors cables would have struggled with M20 - plus I hate butchering enclosures, and I don't know how "butcherable" these are either), plus a higher amperage rating (handy if I ever get bigger pumps).

Now I just need it all to show up! I'll post an update after I've chucked it all together.

Offline OTG

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Re: Solar Water Transfer Pump
« Reply #9 on: October 13, 2018, 11:59:09 pm »
Well, I got the switch in last weekend and it's now working a treat with the bore pump.

The screw pump for the tank also arrived and is fitted with another shroud ready to drop in the tank - I just need a few more conduit bits to run the power cable to the tank and then I can drop it in!

A few points about the switch:
 - the enclosure actually has those rubberised "knockouts" that you're supposed to break away (but not cut-out, for whatever reason). I've noticed this is increasingly prevalent on a lot of enclosures for some reason? To me, they seem an unnecessary weak-point and I'd personally prefer screwed or plain entries, but as they say... whatcha-gunna-do!?
- it had an additional rubberised hole @ centre bottom about 12mm round (intended for earth or other aux wires I think) which was actually quite handy as I ran the bore power cable through it (the centre black cable - the board sits right above the bore) and the bottom left corrugated conduit I'll run to the tank pump.
- finally the switch can only be mounted one way, which made the wiring messier than it could have been, but again... whatcha-gunna-do.

And a quick pointer on the screw pumps:

I've found that with both my screw pumps, there were a lot of metal shavings (some quite big chunks too) in behind the inlet screen/mesh. ??? It almost looks like the pumps are fully assembled BEFORE they mill the inlet openings in the SS casing because the screws themselves had shavings on them too!  So I'd recommend anybody else getting a screw pump from china, take the screen off and give it a good wipe/rinse out before you prematurely bugger the rubber screw.

Good old Chinese QA!  :P

Offline OTG

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Re: Solar Water Transfer Pump
« Reply #10 on: December 31, 2018, 11:35:53 pm »
Finally wrapping this up... so all the conduit's in, it's wired up, and it's been running great guns for a couple of months now.

The pics are pretty self explanatory, but a few quick points:

- I wanted it all to be fairly modular, so I could take take bits out/off, while leaving other bits in place. So that's why you'll find "air-gaps" between conduit runs and components.
- In this regard, I used two IP56 enclosures (mounted on the bore casing using hose clamps run through short cut lengths of some spare solar rail which the enclosures are screwed onto) to terminate the tank pump power cable (coming out the gland) and the solar panel cable (terminated with MC4 surface mount connectors). I also wrapped some spare hessian cloth around the bottom of exposed conduit/pipe to keep the early/late morning sun off it (just to help it all last that bit longer).
- I also ended up using 3 x Wago 222 Terminal Blocks for connecting the pump in the tank (they're stored in the pictured IP56 enclosure screwed onto the tank itself). This way I can simply lift the lever clamps to disconnect the pump power cable, without damaging the conductors, unlike a screwed terminal block, or worse still - picking apart heat-shrink/crimp terminals).
- Finally I found tilt mount legs to be the cheapest way to mount the panel - so no more anderson plug (this paddock was previously cultivated and fence posts move about in the ground, so I reckon a pole mount would have had a slant to it in no time anyways). I offset it to the NW from the little power/shed as the valley behind it can bring nasty gusts up from the SE during storm season - so it's a bit of extra protection.

For a remote bore/tank pumping set-up, I don't think I could have done much better/simpler for the money. Thanks again to Oz/Ross for the advice.


Offline oztules

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Re: Solar Water Transfer Pump
« Reply #11 on: January 05, 2019, 06:03:04 am »
Looking good. It is truly amazing how the Chinese have changed the pumping of water.

It was wildly expensive only a few years ago, now you can get for less than $200 a bore screw pump of some 285 watts, free shipping.. from Sydney.... with built in controller... just add panels :)

The same sort of thing used to be over $20000 for a mono system 14 years ago when I was interested.... for a few seconds at least.... and not as good either.

I make my own solar BLDC pump controllers now, and you can buy the rotor stator for most sizes for only 20-30 dollars from Aliexpress.... and so you can then make your own pump........ similar to the mono AGP series.....for peanuts....... the world has certainly changed.

For the BLDC motor, a F&P works just fine with a rewire of the phases for low voltage.....

But your setup looks the part.... well done.


.........oztules
Flinders Island...... Australia

Offline OTG

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Re: Solar Water Transfer Pump
« Reply #12 on: January 26, 2019, 10:20:48 pm »
Thanks Oz - and yes I'm chuffed with the solar screw pumps thus far (in all regards - price/performance)... I'd say they're damn near the best thing since sliced bread!

How good are those $200ish units though? The ones I've seen look a bit cheap (the AliExpress seller even told me not to bother with them - reckons they use cheaper/thinner SS bits and wont last as long) and don't have much head either (+-20m). I'd be interested to hear your experiences with them and/or if you could provide links to any "good ones".

Also here's a snap of the tank termination, I forgot to include above. I've used a bit of old colorbond ridge capping as a roof/vertical shroud (removed for the picture), again to keep the sun off and help everything last that bit longer -

Offline oztules

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Re: Solar Water Transfer Pump
« Reply #13 on: January 28, 2019, 12:05:54 am »
There are some cheap ones and some cheap ones.

If you can see a huge circlip on the bottom, then this means that there is a true motor in there with bearings. The ones without this circlip use plastic bearings in water not oil.... hence they don't need the circlip for the oil bath arrangement.

The circlip one uses a " normal " screw from china. about 24 dollars replacement for all sizes from Aliexpress ( AUD).

So it will depend on your use. If just filling a header tank of 10-20 meters, the circlip one is ok. The motor will last like any three phase BLDC in an oilbath. The screw is the same ( in the one I got to play with for a day).... I think it was rated for 40m, 285 watts.24v.

It is out in the ocean at the moment, so I cant look at it..... probably for months.

But like I say, there are plenty of them out there and they are of two different types.
Note: the plastic bearings are pretty good unless you run them dry for a few moments.... then it is a disaster. There are some name brands that use the plastic journals too. The right material will probably last like a real bearing if kept lubricated with cool CLEAN water.

The one that you have is good, and has control, the cheapies are full speed only. The controller is internal, but at least they are BLDC.
The SS thickness is pretty immaterial, but they are really throw away, as not as easy to service as the "real" ones from the looks.

In a few months we should be able to get some better information from the one I got for testing out in the sea.



..........oztules
Flinders Island...... Australia

Offline OTG

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Re: Solar Water Transfer Pump
« Reply #14 on: January 28, 2019, 12:30:56 am »
Thanks Oz - that summed it up nicely, most helpful!

The ready availability of cheap rotors/stators is indeed a boon...

I'd be interested to hear how your test unit holds up, be sure to post an update when you do pull it out of the drink.