RP-M - Is this shuddering normal?

[92Miata]

I've got it in pulse mode - and the blade seems to shudder during the 'stop' phase. None of my other pumps do this when put in start-stop modes - so I'm curious.

 

[Reef Breeders]

Is it making a noise? If not- then that's normal. It's a sine wave pulse- so it's not supposed to come to a complete full stop. The impeller is quite large so the pump keeps moving as a full stop would require a bit more energy to get going.

 

[92Miata]

Is it making a noise? If not- then that's normal. It's a sine wave pulse- so it's not supposed to come to a complete full stop. The impeller is quite large so the pump keeps moving as a full stop would require a bit more energy to get going.

Its whining a touch - but not more than I typically expect out of pumps the first couple days.

Just to be clear - Its in F2 - I think speed 5 or 6.

I had assumed from the diagrams it would stop - but if its twitching forward as a sort of soft-start - then I think its doing what it's supposed to and no worries.

Thanks

 

[92Miata]

Spoke too soon - now its binding up about once a minute and making a thumping noise. You can see it at about 35 seconds into this video.

 

[Reef Breeders]

Okay. Go ahead and email us at [email protected] with your order number for a replacement impeller.