Grundfos CU 301 Notice D'installation Et De Fonctionnement page 23

Fault
6. Even after
replacement, CU
301 indicates "No
contact to pump".
7. CU 301 indicates
"Overvoltage" or
"Undervoltage".
8. CU 301 indicates
"Dry running".
9. CU 301 indicates
"Speed reduction"
and
"Undervoltage".
10. CU 301 indicates
"Speed reduction"
and "Overload".
Possible cause Remedy
a) Numbering of If an SQE/CU 301 system has been given a number, this
SQE pump and number is stored in both SQE and CU 301.
CU 301 is A new CU 301 will probably not have a number
different. corresponding to the number stored in SQE. Therefore, "No
contact to pump" is indicated even if there is no fault.
Give the new system a number between 1 and 64 in order
to obtain correspondence between the numbering of the
SQE pump and CU 301.
Note that two systems on the same power supply must not
have the same number!
a) The supply Check - possibly over a period of time - that the supply
voltage is voltage is according to the values below.
unstable or Voltage range for 200-240 V motors:
outside the
• Motor type 0.5 hp is equal to 198 V - 280 V
voltage range
• Motor type 0.75 hp is equal to 198 V - 280 V
specified for the
• Motor type 1.0 hp is equal to 207 V - 280 V
installed motor
• Motor type 1.5 hp is equal to 207 V - 280 V.
type.
Voltage range for 100- 115 V motors:
• Motor type 0.5 hp is equal to 90 V - 150 V.
If the power consumption is lower than the dry-running stop setting, and the motor
speed is within 1,000 rpm of programmed maximum speed, for an accumulated
period of 5 seconds, the pump stops.
a) The pump
Replace the pump with a smaller pump or reduce the pump
performance is
performance by lowering the maximum speed or reduce set
too high for the
pressure.
well yield.
b) The well screen Check the well capacity and restore water supply to the
is blocked. well.
c) The dry-running
Check and correct the setting. See section
stop setting is
running
incorrect.
Speed reduction is activated so as to maintain a reduced performance. When the
supply voltage falls so low that it can no longer supply the necessary current to
1
maintain 3000 rpm , the pump will be stopped.
a) The supply
voltage is
unstable or
lower than the
Restore correct supply voltage.
voltage range
specified for the
installed motor
type.
b) The pump is not
of the correct Install correct pump type.
type.
c) The voltage
drop in the
Replace the pump cable with lower gauge wires.
pump cable is
too big.
Speed reduction is activated to maintain a reduced performance.
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.
As the voltage is detected at the motor, allow for the
voltage drop in the pump cable.
stop.
6.3.7 Dry-
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