Tunze 6100 pumps don't actuate under 20%....!

erikages

New member
Hi, folks. I noticed this evening (with my flashlight spying on various tank critters) that one of my Tunze 6100s wasn't spinning. Not something I usually look at, as their bodies are fairly well--but safely--hidden in rocks.

So I looked at my Profilux and the pumps were in night mode, and indicated pump variations between 15% and 25%, which I'd selected for the two 6100s in the system at night (there's a Tunze nano stream pump I've directed at the surface that runs 24/7). I switched on lightning mode to bring the pumps up to variations on full, and then carefully watched. Whenever the pump program ranged below 20%, the actual pump blades shut down, causing multiple full-on and full-off sequences when ranging around or under the 20% level.

As near as I can gather, this rapid full on-off stuff isn't good for the pumps. I've adjusted night and minimum modes above 20% at this point, and turned Tunze's flow control boxes to near minimum (still hugely powerful).

Any idea why this is so? It's a bit disarming to discover that what you read on the Profilux display isn't what's actually happening in the tank.

I'm sure it's just a bit of basic electrical knowledge to which I'm oblivious, but I'm curious.

Regards,

Erik
 
ProfiLux only outputs a control voltage between 0V and 10V (100%) and "hopes" that the pump works as wanted. ProfiLux can't check the actual current flow of a pump and doesn't know if the pump is working or not. You have to do your settings according to the physical capabilities of your pump; that means: the pump should be able to work at the lowest percentage (= voltage).
As far as i know the Tunze pumps work safely above 30%.
 
With thanks! I've adopted the 30% rule

With thanks! I've adopted the 30% rule

I knew it was some kind of electrical principle. Glad I caught this, and greatful for your feedback.

30% it is.
 
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