Whirlpool's new dishwasher motors

[murando531]

I was in Lowe's today, and for whatever reason a new Whirlpool dishwasher was upside down on a dolly. Not sure if it was a display or what, but the door was bent. I took the opportunity to scope out the underside since I've never seen the motor assembly in person, but I didn't get to sneak pictures.

I have to say, I knew that WP was putting much, much less powerful motors in their line along with their KitchenAid and Kenmore models, but I was shocked to realize that the main wash pump is literally a slightly larger induction motor, identical to the motors being used as the independent drain pumps in washers and dishwashers.

It makes sense now why they can't use all arms at once, or have a chopper blade equipped; they simply don't have the power. This is also the same motor type that is used in fountain pumps, and the one that sometimes makes sort of a chatter when kicking on in your washer/dw during drains because the magnetic pulses kick the rotor back and forth rapidly until it has enough momentum to spin in one direction or the other. On one hand it's to be expected with the energy "issues" these days, but I would never think that a glorified drain pump would have the power needed to put out good volume and pressure from the spray arms in a dishwasher.

This also makes me wonder that if you put your ear down next to the machine when it starts up, will you hear that telltale chatter that induction motors sometimes make? I'd also like to hear anyone's experience with these models, as this type of motor typically isn't supposed to run more than a little while at a time.

 

[murando531]

I also looked up the drain pump for my 2012 Whirlpool washer, and posted pictures below. They almost look identical, and according to the ratings on the labels they almost are. The times I've pulled the hose over into the tub to recirculate water when deep cleaning the machine, the volume and pressure coming out are okay, but they're just a trickle in comparison to the power of the AC motors found in the previous gen WPs and current Maytags.

Now I wish someone I know would install one just so I could run a GoPro inside it and see how they truly perform inside, and so I could hear what one sounds like of course.

 

[arbilab]

Those aren't even "statue pissing into pond" motors. Unless you can tolerate your statue pissing 10min out of every hour and absolutely no more. They are extremely inefficient, a figure of merit worse than the previous shaded-pole small pump motor.

Note the duty cycle on the label(s). Absolutely no more than 50%, and as low as 20%. That's because they get SO HOT in those short operating times they are in danger of smoking the coil insulation.

The 'Maytag Man' had one out of the coinop Neptune downstairs, accidentally touched the motor part and it burned the tihs out of him. You could even SMELL how hot it was.

Manufacturers love them. There are no bearings and no seals. There's not even a shaft. I can't imagine using that style motor as a dishwasher pump unless it was drain only.

 

[frigilux]

How does it manage a 50% on/50% off protocol during a dishwasher cycle? Does it run for, say, one minute, then pause for one minute before switching racks?

 

[mrb627]

Interesting Topic

I also noticed from the label that the motor is made in Italy.
I'm also curious about the 15 on/15 off label. It strikes me as a bit undersized for a recirculating pump. Perhaps it is a clue as to why the door was bent...

Malcolm

On a side note, Askoll builds pumps for almost every manufacturer out there...

 

[tolivac]

I beleive the limited duty shaded pole pump motor was for draining the tank only.It would only run during the drain cycle.There isn't even the little "tin fan" on the motor to help cool it.Remember in days past these had the little tin fans on them.But the so called dishwasher wash pump motor not much better power wise than the drain motor.SAD-Won't buy ANY new dishwasher if this is what you get.This is getting really low!!

 

[Chetlaham]

If speed queen made dishwashers... I don't think we would be seeing this on their machines. Just when I when the pumps couldn't get tinier they have.

Im going to be honest, consumers are catching on. I hear more complaints in stores about how long the new machines take to finish. One lady put it well "I just want a dishwasher like my old one", when the sales guy said she would have to clean the filter at the bottom of the thing.

 

[henene4]

80W recirc pump???

OK? I mean, don't get me wrong, but even our A+++ -10% DW still use pumps 150W or more. This is a joke.
Especially, if I think about it, DW with varibale speed/presure/power pumps now run down to the 500€ price range, I can't get that. These units can change speed and thus usage and power. They are like the brushless motor to washers: Silenter, more efficent, over all more durable and more flexible. So, using these pumps (and Askoll produces such as well as far as I know) allows you to do a long, low pressure wash profile as well as a power blast. And they are not a thing that would launch prices...

 

[murando531]

I guess that would also explain why the manuals on the new WP/KM/KA dishwashers state that "Your new dishwasher will pause periodically to allow the detergent to soak". I guess if it didn't, these little pumps would burn out quickly.

Like someone said earlier, I never thought I'd see this type motor used for anything BUT draining, because there's simply no power behind them. They work well for that purpose, but they are slower at getting the job of emptying the machine than previous systems.

I wish I had gotten pictures of the upside down dishwasher. The pictures you see on the internet are misleading, because the camera angles make it seem larger. In person it's almost pitiful. There's alot of empty space under these machines, that's for sure.

 

[washman]

Well we got what we wanted?

Right?

So much for being green or efficient. I'm 1.5 hours into a 3 hour cycle on the eco-sanctioned GE.

It pauses too throughout the cycle. All the manual says is this is "normal" operation but I suspect as noted above that the cheap made someplace else besides here motor just can't handle running full chat for 3 hours.

 

[washer111]

Ouch...

I honestly think the future of dishwasher motors will be similar to the ones used in pond-pumps... Those use a magnetic casing, and impeller, so the impeller itself becomes a motor and pump.

 

This is the method used in the DishDrawer. It might only draw <100w of power, but it moves PLENTY of water around (single wash-arm - but not a "rain shower," its more like a thunderstorm), never has to stop to let the water return to the sump, and it doesn't seem to mind gobbling rice every now and then. 

 

 

 

[DADoES]

 
DishDrawer pump is rated 60w.  3-phase, 80V DC.  Runs at 2,300 to 2,850 RPM for recirculation, reverses to 4,200 RPM for drain.

 

[murando531]

Which is why I plan to take care of my Maytag MDB4709 so that it lasts as long as it possibly can. I also plan to find a WP PowerClean model to restore. I'd love a Hobart KitchenAid or a Maytag Reverse-Rack, but realistically it would be harder to maintain with the scarcity of parts now, much less 10-20 years from now. I'd use it as the daily driver since they're easy to work on, and if for some reason down the road I have difficulty finding parts, I'd have the Maytag. Granted, this is the plan unless the industry turns itself around and starts building quality machines again. With real motors.

 

[jerrod6]

Hmm and these new things take 3 hours to get the job done.  I guess that might be what a trickle of water is capable of.  It's a shame, and how long are these motors going to last?

 

 

Shameful.

 

[logixx]

In all fairness, though, size ain't everything.  

Dishwashers have developed a little bit since they were first introduced. The big ol' tub with the impeller at the bottom is gone. Today's dishwashers have narrow water paths, spray jets that aim at the dishes and not the tub, tubs and sumps designed to allow water to flow into the pump quickly and quietly. Computers simulate the water flow and engineers can virtually redesign components that cause unwanted turbulence in the water. It's a similar thing with vacuum cleaners: in Europe, we're used to vacuums with 2.000 and more watts motors, when most US vacuums have much less than that. Still, I don't think all of your carpets are dirty (powerheads aside). When Bosch released its new platform, the wattage of the pump was reduced but the overall water circulation increased by 130 gallons because several parts were redesigned.

I'm wondering if these long cycles are an American (or even a Whirlpool) phenomenon. European dishwashers have more powerful heaters, maybe that's what helps them to be faster. On the other hand, they usually run off a cold-water connection. Whirlpool's fastest wash cycle is the One Hour Wash that excludes a drying portion. My Bosch does a load in 55 minutes with drying. V-Zug takes 45 minutes for two washes, two rinses and drying. Now, those are of course not the Eco cycles but they still use less than the One Hour Wash. It really seems Whirlpool started making some slow dishwashers. I don't think Maytags or GEs are that slow.

Today, I ran across one of these Miele Professional dishwashers that look just like a domestic machine. These circulate 50 gpm. It was a showroom model but still sold for over 2.000 Euros. The new undercounter models even go up to 105 gpm. How much did tje old Hobarts blast through their wash arms?

 

[magic_clean]

The picture illustrates

the actual wash pump & motor that is used in Whirlpool tall tub dishwashers since 2011. (There is a separate drain pump motor) Certain models operate both wash arms simultaneously. Others have a flow diverter that allows the wash arms to work independently with a smaller amount of water per fill.

As noted in Logixx message, the filter based wash systems of today are quite different from machines of the past. However, they are more than capable of performing their task. Like any dishwasher, properly installed, dishes racked with some common sense and good detergent and rinse aid..........you'll get clean dishes with modest water & energy use.

...L.P.

 

[washer111]

Size Certainly ISN'T Everyting

Logixx, this is pretty much 100% correct. 

 

If the machine's efficiency in circulation is improved, from better circulation pathways and sprayers, to better filter screens, then water flow can theoretically be increased, and cycles shortened, even with decreasing amounts of water. 

 

As Glenn said, a 60w, 3-phase pump at 80v is more than enough to create a thunderstorm in the DishDrawer, yet the machine uses about 2.3L per fill. 

The design is clearly evolved enough to move the water where it's needed and still produce remarkable results. 

As I've stated time after time, I can get great results in just 60 minutes, without resorting to "heavy" cycles. Given three rinses, it isn't exactly frugal, however. 

 

[murando531]

It's not really the size that is the issue, but rather the type of motor they decided to use. These induction motors have very low power output in relation to the amount of energy they run on. The full-sized AC motor in the new Maytag is rated at 2.7 amps, but it has a very nice brute force output, running at almost 1/3 HP, so in the sense of power vs. energy consumed, it's very efficient, and can run for a long time without needing to cool. The PowerClean outputs 1/3 HP at 5.3 amps, if that gives any idea of the improvement. The motor used in the new WP is only a slightly more involved version of aquarium/pond pumps, which are a simple impeller attached to a cylindrical magnet, inserted into a water tight hub. They work well for continuous use in aquariums and ponds because they're submerged and water cooled as the water can move between the magnet cylinder and hub. In this machine however, they're not under water, and even if they were hot water in a dishwasher can't cool them.

They work tremendously as drain pumps on appliances because they only have to run for maybe five minutes at most. There is no need for force or high pressure because it only needs to move the water from point A to point B.

Maybe it's an attack of nostalgia for me, because I always loved Whirlpool PowerClean and Point Voyager dishwashers that upon looking "under the hood", there's a nice hefty motor there to greet you, and yet while they were powerful and could chew up any food you could throw in, they were also quiet and efficient. It's depressing that what made me fall in love with Whirlpool has now been reduced to a lawn sprinkler in a box.

 

[tolivac]

And those older DW and washer motors had FANS in them to keep them cool-and could run CONTINUOSLY!Fan in those motors was simple but effective-fins cast into the motor rotors shorting rings!Give me a big motor in the dishwasher and short cycle-happy owner-wimpy,tiny,overheating motor in a modern dishwasher-makes me want to take the stupid thing to the plinking section of the shooting range and use it AS A TARGET!!!!Then just do the dishes by hand.I can do mine in well under 3hrs-and no overheating motor worries!