American Dish pump impeller breaking in two, 3 times!
Anyone have any input on this, I'm all ears.
Medium size (think Hobart 44 ish) American Dish dish machine. The main wash pump on this beast is about bog standard- 3-phase motor, seal, cast iron impeller, square key, single bolt in shaft to hold it on.
After running for years with no real problems, we got a call that it had died. Got there to find the pump impeller had broken cleanly in two, at the keyway. It had chewed up the motor shaft so we NDA'd a new motor, seal, impeller, etc. And installed it. 3 weeks later, same call, same result. Factory wanted the motor et al shipped back to the before they'd consider a warrentee replacement. But we had to get the customer up now, so we again ordered the whole shebang and installed it.
Yesterday the call came in again, about 3 weeks. Same result, split impeller, along the keyway, but this time it didn't chew up the shaft, so I ordered just the seal, key, bolt, and impeller, and today I assembled and installed it all.
I can assure you there was nothing in the impeller or pump housing, and with the design of the intake, it's about impossible for anything to be getting down there.
The pump is rotating in the correct direction, and when running is quiet and pumping up a storm.
Factory hemmed and hawwed (izzat a word? : ), finally saying they had a batch of so-so impellers, but I dunno what to think. Every other impeller I've seen would chomp on a fork without breaking, just stalling the motor, or wizzing a green scrubby around for a while making noise.
It's got us a'scratching what little hair we have left.
I have no explanation. I've had a few do this. It's out of an Insinger door-type machine, on which that impeller had reached its service limit. :
That's a major PITA to repeatedly replace those until they send you a good one. An impeller is usually a very expensive part too (a grand or so).
I take it that you saw no evidence of damage to the impeller vanes that would be indicative of some foreign object possibly causing the failure?
You said the manufacturer "hemmed and hawed," then finally said they "had a batch of so-so impellers." Sounds like they need to take the whole lot of what they stock to get NDIed, which is NOT a typical test for dishwasher parts. Aircraft components - YES!
I would write down date/time/names/what was said after each conversation with that manufacturer. I've been known to bit a bit direct with manufacturers by reminding them that their reputation is becoming severely tarnished in the eyes of this customer (I know...I'm just a little guy with no clout...but still...). Of course, I did this unbeknownst to the customer, since I don't share with them my opinions of who makes equipment they own, nor advise for or against any particular manufacturers when they're looking to make a purchase.
Anyway, I've also kept "special situation" files on those "special" manufacturers for awhile so I could review it in case I had to deal with a manufacturer for the same reasons. This situation certainly fits that category.
I've only dealt with American Dish Machine once, since they simply aren't in the market I serviced. I wasn't impressed with their design (such as that monstrosity of a "float switch" they had going on).
Heh. My goodness, what were they pumping, concrete slurry? We worked for a BigPinkDonut chain up north, and they had these monster roll-in rack pot washers. Periodically we would have to replace the pump impellers and *housings* due to the metal just going away! These were like 10 HP pumps. Had to use an engine hoist to lift them up. I guess sugar and flour are very abrasive.
>I take it that you saw no evidence of damage to the impeller vanes
Correct, no wear or impact points that one might expect. Like I said, a puzzler. What I did different this time is the washer they give you that goes under the bolt was only very slightly larger than the impeller ID. I felt like it may be putting outward stress on the impeller, so I added a larger diameter washer underneath to bring the contact point out more.
>I would write down date/time/names/what was said after each conversation with that manufacturer
Oh, rest assured. His name is now written right there on the work order. He's the one who said when I reorder the impeller to explain what was going on and ask for replacement. However, I work for the BigCompany- I never get to order anything. It goes into our computers and then through several people and locations before the order is placed. We are, however a warrentee agent, so I'll just ship them all the bad parts and request coverage.
>nor advise for or against any particular manufacturers when they're looking to make a purchase.
Me neither. However, I might share my opinion of what I'd buy or do if I were to open my restaurant.
Like when I say I would buy the cheapest mechanical thermostat fryer I could find, instead of a top quality name. I say I'd buy the extended warrentee if available. Then when the first out of warrentee repair over an estimated $200 happened, I'd just roll it out to the loading dock and into the dumpster, and buy another cheap one.
I wouldn't buy an oil filter unit. Save your money and just toss out the old oil into the recycle tank and be done with it. I had 2 highly respected and high volume customers back up north who did this, and claimed it saved money and staff never had to handle filters etc.
[/rant off :]
> I wasn't impressed with their design (such as that monstrosity of a "float switch" they had going on).
Who is that manufacturer that has those rotating spring floats? Stero? Has an adjustable length arm on it, square box on the outside, mounts with 4 studs. What a complicated over designed sensitive and expensive float. Gawd, I hated those. Hobart has the best compromise, in my humble opinion, on float design. Not perfect but easy enough to work on, seems solid enough, clever how they turned one upside down to terminate the fill.
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