Do I HAVE to use a CU-200?

pabloesguapopabloesguapo Solar Expert Posts: 91 ✭✭
I am using a Grundfos 16-SQF-10 with a CU-200 controller.  It's all running on AC power from the circuit breaker box, 120v, 20amp breaker.

It looks like the controller is bad.  Do I HAVE to get another CU-200, or can I use a standard, less expensive controller, which I can purchase locally?  (I understand that I would have to replace my pressure switch on the pressure tank too, to a standard model)  $390 vs about $100, that's a big difference.  I'm trying to determine what the advantage is in spending the extra money for a CU-200 again.

Comments

  • EstragonEstragon Registered Users Posts: 1,416 ✭✭✭✭
    You might want to check with grundfos. Some of the extra cost is for features like preventing running the pump dry, which may (or may not) be an issue using the pump with a different controller.

    Does the controller have a GFCI built in? Sometimes they are prone to false trips on long wires, or maybe a developing real problem in the wiring?
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • pabloesguapopabloesguapo Solar Expert Posts: 91 ✭✭
    The pump has built in run dry safety.  Currently, to get us through, i am using an extension cord to the well head, with stripped ends and wire nuts, to power the pump enough to fill the pressure tank.

    The SQFlex pumps are really good about using almost whatever electricity you throw at them, AC or DC.  I am almost wondering if a controller is even necessary.  Why can't i just install a standard pressure switch.  So, when pressure is low enough, the switch closes, the pump runs until max pressure is reached, then opens, thereby cutting power to the pump.  If a simple extension cord works....  But yes, GFCI and surge protection be used.
  • EstragonEstragon Registered Users Posts: 1,416 ✭✭✭✭
    I was sort of wondering if the GFCI might be a source of the problem with the grundfos controller.

    I have an external GFCI breaker box on my submersible lake pump, roughly 100ft from the pump. It's powered by a 240v autotransformer, and I've found it trips if the autotransformer is powered up at the same time as the pump switch is closed. I was also told not to run the line any further, which I would have preferred for deeper water, as this could cause more false trips.

    You don't have the autotransformer issue, but the point is a GFCI is pretty sensitive and may be finding a problem that wiring with a cord may not.
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • geosierranevadageosierranevada Registered Users Posts: 13 ✭✭
    You do not need the controller. My well is low recovery, so i do not use the controller. I run my Grundfos on 110 volts so that i can use a
    Timer every 8 hours and pump for 40 min. I get 240 gal in 24 hours. The low water switch gave out about 4 years ago so i went with the timer.  I need about 400 gal a day and am in the process of havlng a new well drilled. My 5000 gal water tank supplies an on demand pump to supply pressure water to our home. We are 20 miles from grid power. My sqf 2-3 has been great (other then low water cut off not working). My new well will have the same pump in it (new) for i am very happy with it. Having enough solar panels and good batteries is the key to living off grid.      George
    Off grid for 15years. 5KW panels, Trace sw4024, Bergy wind generator. 3 SQF 2 well pump, 12kw back up gen.  Not easy living in the wilderness but it keeps you busy
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