Servicing The Product - Grundfos CU 301 Instrucciones De Instalación Y Funcionamiento

6. 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
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 multicore 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.
bar
5.0
4.5
4.0
3.5
3.0
2.5
2.0
20 to avoid
4.8 Position of LEDs.
CONTROL INDICATOR
SENSOR DEFECTIVE
OVERTEMPERATURE
SPEED REDUCTION
VOLTAGE ALARM
NO CONTACT TO PUMP
Fig. 20
MIN. SPEED
MAX. SPEED
OVER LOAD
19