Reasons for impeller failure

[SkumScraper]

I have a Mag 5 driving an Aqua-C EV-120 skimmer. This has only been running 6 months and I've had 2 impeller failures that I don't understand.

On the impeller, inside the blade assembly, facing the shaft, there is a little plastic key that breaks off. This key is necessary because it grabs the keys on the ceramic shaft.

On the first failure, I thought maybe something had been sucked into the pump, stalling the blades, hence, breaking the key. On the second failure, I'm reasonably sure the line was clear of debris. The prefilter is in place and there is nothing to be sucked in.

Both of these failures have occurred upon startup (after maintenance).

Does anyone else have this problem? Maybe the startup torque of the motor is just too much for this little plastic key.

 

[Fishieness]

You are correct. The key is there to prevent the impeller from breaking off imediatly, but it is still a lot of pressure on a smaller area. How often are you shutting it down? Unless I am cleaning the pump or the entire body, I usually just leave them on while cleaning the skimmer and turn the water level way down. Starting up adds a lot of stress to it.
However, that is still a lot... Your pump may start up especially fast or perhaps you just have some bad luck.

 

[excuzzzeme]

I think a trouble call the the manufacturer is in order. You may have better success talking to them than an email. I would try both and see if you get any response from them.

 

[duke33]

Sounds like a factory thing to me too.

 

[SkumScraper]

Fishie,

I don't stop the pump very often. Maybe once every couple of weeks for one reason or another.

Since I haven't heard anyone else complaining about premature impeller failures in a Mag 5, maybe this is an issue for the factory. Seems that the impeller must be impeded by something in the housing or the startup torque of the motor is high on this particular unit. Don't see how either could happen but I guess that is why I need the factory.

 

[7faces]

I'm running 2 mag drive pumps, and have had no problems with either yet...
the 24, I rebuilt when i got it, and I noticed that there is quite a bit of play between the impellor and shaft, where you can turn the shaft maybe 1/4 inch before the impellor starts to move..
I dont know if its supposed to be like that or not, but I could see there being a problem there, if the shaft gets to spin too far ,and gains momentum, then engages a stationary impellor...that seems like it might break something...
so maybe check that out, and if it is loose, you may try putting a dab of silicone or something between the two where they mesh, to keep it tight untill everything gets spinning..
My 24 is a bit loud, and I'm pointing at this problem as the culprit, and plan to use a bit of silicone like i explained to you to try to quiet it down a bit..
please keep us posted!

 

[7faces]

*double post*