Grundfos CU 301 Instrucciones De Instalación Y Funcionamiento página 23

Fault
12. CU 301 indicates
"Overload".
13. CU 301 indicates
"Sensor defective".
14. The pump is
operating on and
off.
Possible cause Remedy
a) The pump is
worn or The pump must be serviced.
blocked.
b) The pump is too
large for the Replace the pump or motor.
installed motor.
a) The pressure Check that the sensor is installed correctly.
sensor is Check that the Grundfos GO Remote setting of the sensor
defective. is correct.
If the sensor type is 4-20 mA, measure the signal current.
If the current is above 2 mA, the sensor and wiring are OK.
If the current is below 2 mA, the sensor or wiring is
defective.
Replace defective parts.
Are the LED "Sensor defective" and the LED, pos. 1, on?
See section
•
•
a) No Check that the LED "No contact to pump" is on.
communication. If so, CU 301 starts and stops the pump, based on the
sensor signal only. CU 301 has to be reset every 250 stops.
Refer to fault no. 5 for remedy.
4.8 Position of LEDs.
Yes: The total load of 24 VDC from terminal 5 is above
100 mA.
Disconnect the sensor in order to determine if it is
defective.
Replace defective sensor.
No: The load is OK, but the CU 301 sensor input may be
defective.
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