Intelliflo VS -- AWAYS goes into max speed to prime even when fully primed already.

lalittle

Well-known member
Apr 4, 2011
184
Los Angeles, CA
My Pentair Intelliflo VS always ramps up to max speed when it starts even if it's fully primed. According to the manual, this shouldn't be happening. This is what the manual says:

The priming feature ramps the pump to 1800 RPM and
pauses for three (3) seconds. If there is sufficient water
flow in the pump basket, the pump will go out of priming
mode and run its commanded speed.

If the water flow is not sufficient, the pump will ramp
to the “Max Speed” setting and remain for the priming
delay time (default 20 seconds). If there is sufficient water
flow in the pump basket at this time, it will go out of
priming mode and ramp to the commanded speed.​

If my pump is running even with almost no bubbles in the window (i.e. it's fully primed) and I turn it off and back on again, it still ramps up to max after the 3 seconds at 1800 RPM. It does drop down to normal speed after the 20 second "priming delay" time, but the basket it totally full of water, so why doesn't it sense prime after the initial 3 seconds?

This pump has a setting called "Primed Sensitivity" which says:

Priming sensitivity can be set from 1 - 100%. 1% means the pump is the most
sensitive to sensing if pump has attained prime. Increasing % will decrease amount of
flow needed for pump to sense prime.

Increase the % if the pump clearly has water in the basket but is having trouble coming
out of priming mode. Setting this number too high can cause the pump to think it has
attained a prime when it has not.​

I tried increasing the sensitivity up to 100 (the max), but it STILL insists on ramping up to max after the 3 seconds at 1800 RPM. Does it sound like something is malfunctioning, or is there something else I should try? Does anyone know how the pump senses prime? If it's back pressure, is it possible that my Quad 100 is creating to little back pressure that the pump has trouble sensing prime? Even if this is the case, shouldn't setting the "Primed Sensitivity" to 100 let it sense prime right away?

Thanks for any feedback on this,

Larry
 
What you describe is normal, it essentially always goes up to the max speed. There is nothing you can do about that. The only control you have is that the max speed is configurable, it applies globally to everything, including priming.

It is sensing current drawn by the motor vs rotational speed of the motor shaft.
 
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