Grundfos CU 301 Manuel D'instructions page 25

13. The CU 301 indi-
cates "Sensor defec-
tive".
14. The pump is operat-
ing on/off.
15. Excess pressure, for
a short moment, at
start of consumption.
8. Technical data
Supply voltage
1 x 100-240 V –10%/+6%, 50/60 Hz, PE.
Power consumption
5 W.
Back-up fuse
Maximum 16 A.
Current consumption
Maximum 130 mA.
Mains borne signalling
Frequency shift keying (FSK).
(132.45 kHz ±0.6 kHz).
Enclosure class
IP 55.
Maximum length between CU 301 and pump
650 feet.
Ambient temperature
• During operation: –22 to +113°F (–30 to +45°C)
(must not be exposed to direct sunlight).
• During storage: –22 to +140°F (–30 to +60°C).
Weight
4.5 lb.
Relative air humidity
Maximum 95%.
Materials
The CU 301 box is made of black PPO.
a) The pressure sensor
is defective.
a) No communication.
a) Cut-in speed is too
high.
Check that the sensor is wired correctly.
Check that the R100 setting of the sensor is correct,
see section 5.3.1.
If the sensor type is 4-20 mA, measure the DC voltage
across the sensor input terminals. If the DC voltage
measured at the sensor input terminals is not between
2 and 10 V the sensor or wiring is defective. Refer to
section 9., page 28, for additional troubleshooting as-
sistance.
Replace defective parts.
Are the LED "Sensor defective" and the LED, pos. 1,
on?
See section 4. Position of LEDs.
Yes: The total load of 24 VDC from terminal 5 is above
100 mA.
Disconnect the sensor in order to determine if it is de-
fective.
Replace defective sensor.
No: The load is OK, but the CU 301 sensor input may
be defective.
Check that the LED "No contact to pump" is on.
If so, the control unit CU 301 starts and stops the
pump, based on the sensor signal only. The CU 301
has to be reset every 250 stops.
Refer to fault no. 5 for remedy.
Reduce the cut-in speed, see section 5.3.7 Cut-in speed.
EMC (electromagnetic compatibility)
According to EN 55014 and EN 55014-2.
Dimensional sketch
8.8"
4.11"
Fig. 19 Dimensional sketch
3.7"
PSI
100
90
80
70
60
50
40
4.11"
25