Author Topic: Replacing another Grundfos VFD, SQE, CU301  (Read 20007 times)

Cary Austin

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Replacing another Grundfos VFD, SQE, CU301
« on: December 31, 2008, 09:00:19 AM »

I have had a Grundfos CU301 w/a 15SQE-250 running my combined domestic
and GWHP system for the last 11 months. Recently, I started getting
the "VOLTAGE ALARM" coupled w/the "NO CONTACT WITH PUMP" LEDs lighting
up! Pump still locks in at the 40PSI, but surges at startup and stops
at 90PSI. Very unstable.

Took your advice as I have seen posted on this and several other well
pump related sites. I originally did not side w/the CSV camp and went
w/the VFD camp as seen above. After reviewing many of your well argued
and calculated discussions on these two systems, I decided to purchase
the CSVZ1 and a standard pressure switch (30/50) w/auto-start-stop

I have attached several pix showing my CSV replacement so you can see
my setup. Also, I attached a diagram of my domestic & GWHP well
system. It is a Standing Column Well (SCW) that recycles back to the
source well and uses the domestic water usage to maintain the well's
thermal dynamics (~54-60 degrees).

I really like the "simplicity" of the CSV as opposed to the "complex
technical & faulty" VFD setups!


« Last Edit: May 28, 2010, 09:22:36 PM by Kris McCoy »