AUTO vs ON, on variable ports ... Tunze hums

[ostrow]

I sent this to Neptune but wonder if others experience this at all. I have 1 6205 and 2 6105s, the issue is with just one of the 6105s. Read on!



I think ​I know the answers here but want to check.

When a variable speed outlet is set to "ON", does it still follow the parameters of the outlet programming?

I ask because one of my 6105s has been making a loud humming noise, continuous at night. Only one. Night mode has all three Tunzes at 30%.

When I switched the outlet from AUTO to "ON", the humming disappeared. I adjusted the output in the night profile up to 40 but the humming remains on the one pump when in AUTO mode. Hum disappears when outlet is "ON" but it seems still to put out the same power, rather than going to full power. I don't detect a switch to 100% at all.

So, what does "ON" mean? Does an outlet that is ON still follows the programming in the outlet setup?

But then, why a "hum" in the AUTO and not in the ON position?

Any ideas? It is clearly not a pump problem because the pump works and is silent when the ON setting is in effect. I wonder if AUTO sends a different frequency of some sort to the pump?

I'm worried that the pump could be damaged, and it is loud enough to be annoying.

 

[swearint]

When the VS port is set to Manual ON, there should be a constant 100% (10VDC) signal to the pump, ignoring any profiles. When set to AUTO, it will follow the port code and apply the appropriate profile. When set to Manual OFF, there should be a constant 0% (0 VDC) signal to the pump. Have you tried to switch the suspect pump to a different port to see if the behavior follows?

Todd

 

[ostrow]

Todd: thanks. That will be the next step. Sigh.

 

[Deleted member 143833]

Have you tried moving the pump slightly? The nature of a pump, mounted to the glass can resonate when set to just the correct value and from your description that may be what you are hearing. I finally ordered the sounds dampening mounts for all my pumps because I always had 1 setting that would hum more loudly than another no matter what I did. The new mounts solved all the noise issues.