Iwaki md55 actual wattage used
 

After some controversy regarding wattage use/d and head height, a kill a watt was purchased so I could do this test. It was always my opinion that impeller design plays a larger role in wattage use and head height than just saying AC pumps pull "much less" wattage at higher head pressure. It certainly is not true for the Iwaki.

Results are for a 15 year old Iwaki MD 55 with a clean impeller.

at 11' the wattage was 160W

at 2'-3' the wattage was 163W

Not much difference as I expected for this design.

Quite the energy pig for 24/7 use. At our current rates I was spending $223 a year on electricity.

My current Jebao DCP dc pump is pulling 58W with the same flow at a cost of $81 a year.

That is a savings of $142 each year the pump last


This completely bust anyone's fallacious claims that AC and DC pumps use the same wattage for equal flow rates. Both pumps used the same exact plumbing as both are hard plumbed into my loop. AC pump for water changes, and DC pump for recirculation.

Well, if these numbers are correct and both pumps produce same output power (i.e. head pressure, water flow) then Iwaki pump should produce 160W-50W = 100W of heat. Assuming 100% efficiency of Jebao pump.

Such pump would glow in the dark. Or produce really warm water.

If order to verify all these claims, one needs to carefully measure flow rate and water pressure in order to calculate pump output power.

In reality, both brushless DC motors and AC motors has very close efficiency. BLDC - about 90% and AC about 88%.

What could explain the situation is that Iwaki is overkill for a given situation. For example, it may produce 100 GPM of water with 10 psi of pressure (approximately, 23 ft of head). And DC pump has 100 GPM with 4.5 psi (10 ft). Different output power.
If your head pressure is only 10ft, then Iwaki shoots water out with extra 10ft of head (neglecting friction losses). If you don't need that extra power, then BLDC pump is sufficient and Iwaki is overkill.

However, it has nothing to do with pump efficiency. It just show miscalculated pump power

Iwaki MD55 listed specs: 1.6A @110 (176W)and 18.4gpm (1104 gph) 26.9ft max head.
https://www.iwakiamerica.com/Literat.../MD5570100.pdf
o/p's findings seem w/in specs..
No idea about which Jaebo..or any comparison specs..
Picking DCP-6500

The DCP 10000 turned down so that the digital display states 75% and also 50W but measured at the wall it is 55W

The DCP 10000 is an 80W pump at 100%.

Iwaki's do run hot, this pump you can keep your hand on and its not hot per say but it is a little more than just warm. Never warmed my water were I noticed in over a decade of use.

I have an Iwaki MD15 and that little sucker runs extremely hot, hands on pump is almost burning but I can keep it there. These small Iwaki's are judged by how many seconds you can keep your hand on, and they give warnings of just how hot they run.


As far as output, I turned down the DC pump until I matched flow, which ended up being 55W measured at the wall.

The difference here is the impeller design. The whole DC impeller probably weighs 30 X less then the Iwaki pump. Difference here is the Iwaki will last decades and the Jeboa might not last a decade, that and due to impeller design, the Iwaki has much higher head height and flow, the DC pump is almost at its limits.

Its already done, I run my ATS off my drain return which has an overflow based on flow and with each I get a trickle out of the overflow showing 100% exact flow. Again I dialed the DC pump to match the exact flow.

In a perfect world with identical designed impellers and pump designs, maybe so.

But we are talking about different pump designs and different impellers, and I'm curious if an AC pumps could be built to match said efficiency. At this point without the adjustability, its hard to say.

Agreed. Bottom line is $, electricity money to be exact. Enough to buy 2 DC pumps a year.

The trade off is reliability. To date, no affordable DC pump has the reliability of Iwaki which is one of the best AC pumps on the market.


I never used to worry about the electricity bill, and if one wanted a great basement pump, one bought one of these high wattage pumps, It was all we had. Finally the DC pumps have advanced enough and prices have came down low enough, its actually cost effective to switch methods. Glad I did.

I didn't know how to do the math using amps, and somewhere I read it was 195W.

Thank you for the correction.

My opps........... spec sheet 115V 1.6A = 184

I learned many years ago we do not need pressure pumps for our aquariums. My perfect ac pump was a Pan World 50PXX a true 1140 gph at 80 watts, versus other AC and DC pumps that list 2,000 but at 5' drops down to 1,000gph

Depends a bit on what you are asking it to do. In my case, pumping up from a basement sump, the PXX models just don't cut it. For most aquarium applications though, I completely agree. I actually use the 50PXX to push water through my chiller, and I get more gph than the higher wattage 100PX - so volute and impeller design is absolutely part of the efficiency equation. My long held suspicion has been that if anybody made a DC pump for a pressure application like mine, the purported DC efficiency gains would go poof.

BTW, I completely agree with this. I think in order to make a fairer comparison, one should be comparing to pumps designed to perform similar functions. So, pumps designed for flow rather than pressure. In the example from above, the PanWorld 50 comes in two models, a PX and a PXX. Both are essentially equivalent in terms of power but one flow much more water than the other. In most aquarium applications, the PXX will be viewed as much more efficient than the PX. So, I think it is much more about design and design goals than it is inherent AC/DC efficiency. Hells Bells!

One of the main points I have been pushing.

We are talking about basement pumps, and wattage used for actual context.

I have my sump set up high as possible to lower wattage used no matter which pump.

When comparing the two pumps the main advantage is the adjustability of flow of the DC. I think some of the small AC pumps may be competitive but reliability drops off when we get to light weight ceramic shaft impellers.

I think 55W at 600 ish gph at 9' is going to be hard to beat.

All two dozen of the people still using Iwaki md55s appreciate your hard work.

Lol, I run two of them. One pushes water through my MTC HSA 1000 skimmer and needs the extra oomph. They are great pumps and run forever even if not the most efficient!

Same here.

Only problem is the electricity consumption. Not an issue now since I only use it as a mixing filling pump.

Now the smaller ones run hot and that could be an issue, I have a baby md15 and you could barely hold your hand on it for 20 seconds. [in the dead of winter outside lol] I just looked at it as keeping my calcium reactor from freezing.

I'm more than happy with the piece of mind I get from knowing I have a MD-55RLT running my system. Quite, great flow and as far power used to run it one lost coral can cost more than the power bill for the year to run the pump

How would one loose coral?

Now if I was out of town a lot, I would still use it for such. But if a return pump goes down for a day or two, and you loose coral, your system was set up poorly.

If mine went down for a week, I would have a slight drop in Alk and Nitrates would rise just a hair at best.

Depends on your livestock. If one runs mainly soft coral , it wouldn’t be a problem, that being said an SPS tank, alk can drop pretty quickly.
In warm climates not a problem but cold climates with heaters in the sump, it can pose a problem.
One of the best fall backs you can do is to run 2 return pumps throttled back. If one fails you have the other still keeping flow going.With the price of Jebao’s one could easily afford to run 2 at the same time. What I don’t know is if one were to run 2 Jebao pumps , would that negate any energy savings vs running a reliable say Eheim 1262 pump? Perhaps Outy can break this down for us as I am curious as well.

What I was trying to say is with the cost of some of the higher end frags now days and running a 200+ gal sps tank I'm not worried about cost of power for a pump. I've had AEFWs cost me more in six months than my pump is going to cost to run over the next 30 years LOL