Grundfos CU 301 Notice D'installation Et De Fonctionnement page 21

Fault
5. CU 301 indicates
"No contact to
pump".
6. Even after
replacement, CU
301 indicates "No
contact to pump".
Possible cause Remedy
a) The motor is not If the pump has already worked satisfactorily with a CU 301
an MSE 3. or a CU 300, the motor can be expected to be an MSE 3.
There is no technical way of determining the motor type.
The only way is to read the nameplate engraved in the
motor sleeve.
b) The pump cable
is longer than Reduce the length of the pump cable.
200 metres.
c) Cable Switch off the mains supply to CU 301.
breakage. Switch on the mains supply again. The pump is now
connected directly to the mains supply without interference
from CU 301.
Does the motor start?
•
•
Is the cable OK?
•
•
d) Cross If another CU 301 is installed:
communication •
with adjacent
CU 301.
•
e) The CU 301 Are the three CU 301 supply board LEDs in pos. 2, 3 and 4
communication on and is the control indicator LED flashing? See section
part is defective.
4.8 Position of
•
The mains supply is OK.
Give the system a new number.
If this does not work, CU 301 or the motor communication
part is defective.
Replace CU 301 and 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 mains supply must not
have the same number!
Is the LED "No contact to pump" of the new CU 301 also
on?
•
•
f) The MSE 3
motor As a consequence of the above-mentioned checks, replace
communication the MSE 3 motor.
part is defective.
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 mains supply must not
have the same number!
Yes: The cable is OK. Go to point d).
No: Switch off the mains supply again. Remove the
cable and cable plug from the motor and carry out
megging of the cable including the plug.
Yes: The motor is defective. Replace the motor.
No: Replace the cable.
Ensure each unit has a unique number assigned. See
section
5.3.11 Number.
If pump cables run parallel to each other, physically
separate them by 12-14 inches or rewire using shielded
cable.
LEDs.
Yes:
Yes: CU 301 is OK.
No: CU 301 which was removed is defective.
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