Troubleshooting; Troubleshooting With Grundfos Go Remote - Grundfos CU 301 Instrucciones De Instalacion Y Operacion

8. Troubleshooting

DANGER
Electric shock
Death or serious personal injury
- Before starting any work on the
product, make sure that the power
supply has been switched off and that it
cannot be accidentally switched on.
- Troubleshooting and service must be
carried out by qualified persons.
Fault
1. No light in the front
cover.
2. The pump does not
start. The green
indicator light in the
on/off button is on.
No alarm is
indicated.
3. The pressure is not
constant.
4. The pump is
running
continuously.
Possible cause Remedy
a) The ribbon •
cable
connection is
•
loose or
defective.
a) CU 301, the •
pressure sensor
or the pump is
•
defective.
•
•
a) The pump is not •
of the correct
type or the
precharge
pressure of the
diaphragm tank
•
is incorrect.
•
•
a) The pump •
cannot deliver
the pressure
set. CU 301 or
the sensor is
•
defective.
•
•
•
8.1 Troubleshooting with Grundfos GO
Remote
The easiest way is to troubleshoot the product using
Grundfos GO Remote. Error codes can be extracted
from the unit and read on the device.
Is the control indicator LED flashing?
If not, CU 301 is defective.
Check that the ribbon cable connection is secure.
If so, CU 301 is defective. Contact Grundfos.
Check that the control indicator LED is flashing.
If not, CU 301 is defective.
Check that the system pressure is 7 psi below the
pressure setting.
If so, the pump is supposed to start. Open a tap to be
sure.
If the pump starts, the system is probably OK.
The system pressure can be read on the pressure
gauge.
See fault No 13 to troubleshoot the pressure sensor.
If the pump has not started yet, proceed as follows:
Press and hold the on/off button for 5 seconds.
If the pump starts, CU 301 or the sensor may be
defective.
Note that the pressure is not controlled and may rise to
a high level.
Check that the LED for "Max. speed" or "Min. speed" is
on.
If so, this indicates that the pump has reached a limit.
See section 4.2 System
necessary.
Check the precharge pressure of the diaphragm tank.
Remember to stop the system and drain the tank before
the pressure is checked.
Ensure the diaphragm tank is a 2 gal tank.
Check whether the sensor is positioned far away from
the tap.
If so, the pressure variations may be caused by friction
losses. See section 3.3 Positioning the pressure
sensor.
Try to lower the pressure setting. See section
4.2 System sizing.
Note that the pump may run for about 15 to 20 seconds
before it stops.
Check that the control indicator LED is flashing.
Check that the pipe end of the sensor is not blocked.
If so, remove the blockage.
Try to stop the pump by using the on/off button.
If this is not possible, CU 301 is defective. Replace CU
301.
See fault No 13 to troubleshoot the pressure sensor.
sizing. Replace the pump, if
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