Another decent 12v pump
 

Heard about these about 2yrs back, and have been curious about them ever since. Well my curiosity has gotten the better of me and I've ordered one of these:

March 893-09

http://www.marchpump.com/images/brushless2.jpg

Yes - the model number on the picture is a typo.

Very small. 10cm long x 7cm high x 6cm wide.

Being an industry quality pump, has a fully qualified 50,000hrs MTBF with a fully sealed (and submersible) brushless DC motor.

12VDC. 12W peak power consumption in wide-open mode. I would imagine it would draw less when operating against resistance.

According to the sales engineer who has heard both, says it's near silent and quite a deal quieter than the Laing D4.

It has a peak pressure and flow rate very similar to the old Swiftech MCP600, but it's PQ curve is more attractive than the MCP600 with it still offering very good pressure (~2.15mH2O) at 2gpm, unlike the MCP600's ~1.5mH2O.

http://www.marchpump.com/images/1c.gif

For moderate to highly restrictive systems, the PQ curve implies that it would offer flow rates that very closely matches the newer muffled Laing D4 revisions at anything up to around 8LPM (~2.1GPM), and still be drawing substantially less power, and due to the separated magnetic armature (like the MCP600's had) be putting less heat into the water as well (I would estimate about half).

The pump comes with either 3/8" or 1/2" OD outlets, and people can fit whatever barb size they want on the inlet. Personally I'll be fitting a 5/8" OD barb on the inlet.

Rated voltage operational range is 7-14v.

Once I get this baby I'll assemble a full 12v pump lineup review which will include the following:

Davies-Craig EBP (Australian automotive cooling system booster pump)
Swiftech MCP600
Swiftech MCP650
Laing D4 (original non-muffled version)
March 893-09-1/2 (1/2" outlet version of 893)

Will assess peak flow, peak pressure, pump power draw, pump power->water heat transfer ratio, and measured flow rates in a full system, along with estimated flow rates for some hypothetical systems.

Only drawback is the price. $125US for a single pump through the local USA reseller I tried. I would imagine that in bulk with the "usual" water-cooling market tight margins, a company might be able to offer it for ~$100US if sourced direct from the manufacturer.

Since the torque required to turn the rotor would increase under load, and since the torque of a DC motor is related to the winding current, wouldn't an increase in load also require an increase in current?

Okay, now I'm stressed to the max.

Looked at my credit card statement, and ~$6200US has been billed to my credit card, instead of what should have been ~$145US (pump + postage).

Rang up my bank to put the matter into dispute, now I'm chewing my nails.

I'd love to see a C-Systems CSP750 in that roundup.

you should know better than to call all those 900 numbers.

Huh? Weren't no 900 number. Dealt with these guys before without problem.

If it's on a credit card, then you're safe although it might take time to get it ironed out.

lol, hes taking the piss and you're too worried to realise

Hell, i know i would be

Yeah - but that's not how the financial institution sells it to you when you call them up.

"You need to get them to do this"

"You need to chase them up and get them to contact us"

They don't really re-assure you when you contact the bank with the issue. :(

Off Topic here:

I was at the Iwaki America website a couple days ago and found this:

http://www.iwakiwalchem.com/iwaki/pr...mddcmotors.htm

12V option on the MD series? Has anyone seen these in the wild? Would be interesting to see info on current draw and effect on the flow rates with a 12V motor.......

I look forward to a 12V DC pump that can compete with a Mag3 in performance and price but has the high reliability of the 50,000 MTBF pumps we already have. Even if the pump was $60 it would be a great accomplishment but I'm not holding my breath for even that.

I'm taking that you're unaware that the Laing D4 (MCP650/DD12V) is pretty much exactly what you describe, except at $75.

Why not order it from the local distributor in Melb?

They had stock of the 12V pumps a few months ago.

Price wise, probably the same after shipping from the US.

Cheers,
Jeremy

$350AUD (with postage) vs $200AUD (with postage) is why.

I'd happily support a local company if it didn't cost nearly twice as much to do so.

Well Cathar if you do end up with 50 units of those, ill gladly take one off your hands

LOL - sure - I'll sell them at US$60 each + US$80 postage. :(

Why the -09?
From the March pump PDFs it looks as though the 893s all use the same impeller and impeller housing (non-closed impeller, BTW).
It also looks as though the other candidate might have been the -07 (also brushless but non-submersible). So, I'm guessing you wanted brushless/submersible. Yes? Or is submersible a non issue and you just got a better deal on the -09?
Just wondering.
BTW, I'm really curious how quiet this pump ends up being - hadn't even realized March made a 12VDC model...
Bob

Only the -09 comes with either 3/8" or 1/2" outlet. The -07 only comes in 3/8" outlet. The price difference is something like $2 apparantly between the -07 and the -09.

So the -09 it was then. I would've thought it would be more attractive too in that it could come in either flavor, making it suitable for 3/8" kit users.

Yes - pump noise is what I am most concerned about now.

Sorry to hear about the bank foul up =( I hope it gets all straightened out quickly.

The pump round up you talked about sounds awesome though and am really looking forward to it =)

No I'm well aware of it. The $60 was just me picking something half-way between D4 and Mag3 price, a nice improved price point that wasn't as low as $45.

I don't know. Nice to have things that are cheap - sure. However to buy something that's meant to last for 6-7 yrs running full-time non-stop and then complain about $20 just seems a little strange to me.

I must be an odd person. Whenever I buy something, I tend to divide the cost of the item by the usuable life-span of the item, and the importance of the application of the item, and then decide on that basis whether or not said item is expensive.

The March pump still seems like a good deal to me, even at $120US. $20/yr seems to me to be an asbolute pittance to pay for a rock-solid industrial quality pump.

I don't even consider the Mag 3 as something much better than total junk, what with its propensity to leak and its need to be end-user modified to fix that problem.

I'd rather a pump that was looking after my highly important computing cooling needs for the next 6-7yrs to be engineered and made properly, over-engineered in fact, rather than buying a pump that's barely holding onto its integrity and requires attention from the end-user.

Buying the cheapest possible thing all the time, especially for something that's doing a fairly important job, really is just false economy IMO.

gotta represent the $13 Via Aqua1300

6 months strong

I will be buying the cream of the crop 12v pump when it fails, though

note that March, like C-Systems, has a motor with the 50,000 hr MTBF rating
- not the pump

March has an impeller spinning on a shaft
C-Systems has a steel shaft with a seal
- both weak links if going for 5 yrs service

Absolutely!
For me, this is the attraction of Eheim pumps.
I've built a number of systems over the last few years (all 1046 or 1048 except for one HPPS). They mostly all run 24x7 and I have had no pump problems.

March's spinning on a shaft approach is the same as Eheim or Iwaki. Agreed that it may be a "weak point" if implemented improperly or with sub-standard materials but shaft operation does not automatically imply an inability to operate for ~5yrs non-stop service.

I would imagine the main reason why serious industrial pump manufacturers don't offer exceptional claim guarantees is because their pumps normally get used for pumping all sorts of nasty stuff. Most of the sales engineers I've talked to tend to quote worst case figures to be safe, however if pressed for a clean-water circulation life-span, they've seemed to be a lot more confident in stating longer service times.

I tend to find that a mark of a quality manufacturer is one who will, by default, quote near worst case life-span scenarios, rather than start off by telling you how long it could last for in best-case scenarios.

Whew! Bank just revoked the $6K US charge. Am happier now.