Grundfos CU 301 Manual De Instrucciones página 22

Fault
1. No light in the front
cover.
2. The pump does not
start.
The green indicator
light in the On/Off but-
ton is on.
No alarm is indicated.
3. The pressure is not
constant.
4. The pump is running
continuously.
(continued on the following page)
22
Possible cause
a) The ribbon cable con-
nection is loose or de-
fective.
a) The 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.
b) No contact between
SQE pump and
CU 301 control unit.
a) The pump cannot de-
liver the set pressure.
The CU 301 or the
sensor is defective.
Remedy
• Is the control indicator LED flashing?
If not, the CU 301 is defective.
• Check that the ribbon cable connection is secure.
Check
• that the control indicator LED is flashing.
If not, the CU 301 is defective.
• 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.
• Refer to fault 13 to troubleshoot the pressure sensor.
If the pump has not started yet, proceed as follows:
• Press the On/Off button for 5 seconds.
If the pump starts, the CU 301 or the sensor may be
defective.
Note: 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 1.3 System sizing.
Replace the pump, if necessary.
• the precharge pressure of the diaphragm tank.
Note: Remember to stop and drain the system
before the pressure is checked.
• Make sure the diaphragm tank is the 2 gal. size.
• whether the sensor is positioned far away from the
tap.
If so, the pressure variations may be caused by fric-
tion losses, see section 1.5 Positioning the pressure
sensor.
Check that the LED for "No contact to pump" is on.
If so, go to fault no. 14.
• Try to lower the pressure setting, see section
1.3 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 means of the On/Off button.
If this is not possible, the CU 301 is defective.
Replace the CU 301.
• Refer to fault 13 to troubleshoot the pressure sensor.