Servicing The Product - Grundfos CU 301 Notice D'installation Et De Fonctionnement

7. Servicing the product

CU 301 continuously receives operating data from
the pump. In case of an alarm, the service indicator
light is permanently on. See fig. 19.
Fig. 19 Service alarm indicator
The service indicator light will be permanently on if
one of the following alarm situations occurs:
• Sensor defective
• Overload
• Overtemperature
• Speed reduction
• Voltage alarm
• No contact to pump.
To identify the cause of the service alarm, it is
necessary to remove the front cover from CU 301.
Fit the front cover as shown in fig.
disconnecting the ribbon cable.
A number of LEDs are mounted on the supply board
inside CU 301. See section
Figure 20 shows the LEDs and the alarm texts on the
supply board.
20
PSI
100
90
80
70
60
50
40
20 to avoid
5.8 Position of LEDs.
Fig. 20 LEDs and alarm texts on the supply
board
CONTROL INDICATOR
MIN.SPEED
MAX.SPEED
SENSOR DEFCTIVE
OVERLOAD
OVER TEMPERATURE
SPEED REUCTION
VOLTAGE ALARM
NO CONTACT TO PUMP