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.