Grundfos CU 301 Instrucciones De Instalación Y Operación página 24

Fault Possible cause
6 Even after a)
replacement,
CU 301
indicates "No
contact to
pump".
7 CU 301 a)
indicates
"Overvoltage"
or
"Undervoltage".
8 CU 301 If the power consumption is lower than the dry-running stop setting, and the
indicates "Dry motor speed is within 1,000 rpm of programmed maximum speed, for an
running". accumulated period of 5 seconds, the pump stops.
a)
b)
c)
9 CU 301 Speed reduction is activated so as to maintain a reduced performance. When the
indicates supply voltage falls so low that it can no longer supply the necessary current to
"Speed
maintain 3000 rpm
reduction" and
a)
"Undervoltage".
b)
c)
10 CU 301 Speed reduction is activated to maintain a reduced performance.
indicates
a)
"Speed
reduction" and
"Overload".
b)
24
Numbering of SQE
pump and CU 301 is
different.
The supply voltage is
unstable or outside the
voltage range specified
for the installed motor
type.
The pump performance
is too high for the well
yield.
The well screen is
blocked.
The dry-running stop
setting is incorrect.
1
, the pump will be stopped.
The supply voltage is
unstable or lower than
the voltage range
specified for the
installed motor type.
The pump is not of the
correct type.
The voltage drop in the
pump cable is too big.
The pump is worn or
blocked.
The pump is too large
for the installed motor.
Remedy
If an SQE/CU 301 system has been given a
number, this number is stored in both SQE and
CU 301.
A new CU 301 will probably not have a number
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!
Check - possibly over a period of time - that the
supply voltage is according to the values below.
Voltage range for 200-240 V motors:
• Motor type 0.5 hp is equal to 198 V - 280 V
• Motor type 0.75 hp is equal to 198 V - 280 V
• Motor type 1.0 hp is equal to 207 V - 280 V
• Motor type 1.5 hp is equal to 207 V - 280 V.
Voltage range for 100- 115 V motors:
• Motor type 0.5 hp is equal to 90 V - 150 V.
As the voltage is detected at the motor, allow
for the voltage drop in the pump cable.
Replace the pump with a smaller pump or reduce
the pump performance by lowering the maximum
speed or reduce set pressure.
Check the well capacity and restore water supply
to the well.
Check and correct the setting. See section
6.3.7 Dry-running stop.
Restore correct supply voltage.
Install correct pump type.
Replace the pump cable with lower gauge wires.
The pump must be serviced.
Replace the pump or motor.