Backyard Aquaponics
A place to discuss aquaponics

I was given a few KP250's that are shot to tinker with and have pulled them apart, to have a look. My aim is to clean one up and keep it in my class so the kids can see how the pumps work.

When I pulled them apart the first one is dead clean and the motor shaft and bearings are smooth and appear fine. The other had clearly been run dry and overheated so I thought people might appreciate a picture of what running dry does to the inside of these pumps, this one was cooked nicely.

A few months ago the ebara in my septic system was taken out and replaced because the seal was no good. Rather than replace the seal the pump was replaced under warranty. This was because the septic system must be online and as such if a pump is taken out another goes in. Anyway, that is where these pumps come from (septic systems) so I am hoping that the clean pump may just need a new bottom/impeller seal.

Problem is the power cords have been cut so I can't test it, will have to buy a new one .

Bench tested today. The no-cooked one runs like a dream. I will buy a new powercord/float mechanisim and seal and we will be laughing unless someone has a cooked one that still has a good cord/floatswitch they want to get rid of?

hehe well done

Grundfoss make good pumps, we use them alot at work, not the submersibles so much though. we have had them run dead head for several days on end ( at a university of all places i thought these were the people with the smarts ) with no apparent dammage

CHeers
pete

Yep new they were quality, I think a new KP250 runs around $500. What is "dead head". You got any dead KP's at work that you can borrow a lead/float switch off for me?

Dead head = no flow. ie valve closed etc.

edit!! - Makes them hot as well, probably not too bad with a fully submersible pump though.

sorry mate just got the one we bought recently to pump resin into our softenerand DeIonisation vessels, gotta love a pump that can move solids

and the dead head as OBO explained was a high conductivity level cutout cept for some reason if the tank calls for water the pump just runs dumm huh !

well it used to work that way we have since made the system a bit smarter
Cheers
pete

We used a 1100watt vortex submersible to brew a compost tea in an ibc as it could handle 30mm solids. Turned it on and got distracted next morning the tea temp was cooked and very warm to the touch. Should have realized that an 1100watt motor = approx 1100watt heater in the tank

Went to order a power and float lead for the good pump today and was donated an apparently "burnt out" KP150 that had a lead on it. Stinks like the sewer it was pulled from so is having a nice chlorine bath at the moment.

Cleaned up enough to find the motor is in fact seized but it hasn't cooked, was less than six months old went it packed up and has not been pulled down to be checked so might be able to replace the bearings and get it going too . Amazing that a pump that is still under warranty was not returned to a service agent to be pulled down and looked at - must have come from a rental property

Either way I am a happy camper, one operational KP250 sump pump for nicks , now I just need to find a suitable sump.

I do a fair bit of warranty work for hydraulics, and our labour gets charged out at $125 per hour, so if there is something major like seized bearings etc - a new item gets supplied.

Replacing a bearing is not a problem, but when warranty work is carried out, the item has to be returned in as new condition, so the shaft would be replaced also, and the seals / gaskets etc. Then the pump has to be tested also.....

So it turns into a 3 or 4 hour job by the time its all packed up and cleaned away, which makes it cheaper for the warrantee to just supply a new item.

It is wasteful, but thats the way the labour market is.

Very wasteful, but good for me who was wondering how I was going to afford a decent sump pump. Have sent notice to my septic maintenance guy who is also a mate that I will happily take any stuffed pumps off his hands to see if they can be resurected for AP.