Grundfos CU 301 Manuel D'instructions page 23

5. The CU 301 indi-
cates "No contact to
pump".
6. Even AFTER replace-
ment, the CU 301 in-
dicates "No contact to
pump".
(continued on the following page)
a) The motor is not an
MSE 3.
b) The pump cable is
longer than 650 feet.
c) Cable breakage.
d) Cross communica-
tion with adjacent
CU 301.
e) The CU 301 commu-
nication part is defec-
tive.
f) The MSE 3 motor
communication part is
defective.
a) Numbering of SQE
pump and CU 301 is
different.
If the pump has already worked satisfactorily with a
CU 301 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.
Reduce the length of the pump cable.
Switch off the mains supply to the CU 301.
Connect motor leads directly to the mains supply.
Switch on the mains supply again. The pump is now
connected direct to the mains supply without interfer-
ence from the CU 301.
Does the motor start?
Yes: The cable is OK. Go to point d).
No: Switch off the mains supply again. Remove cable
and cable plug from the motor and ohm out cable in-
cluding plug.
Is the cable OK?
Yes: The motor is defective. Replace the motor.
No: Replace the cable.
If another CU 301 is installed:
• Insure each unit has a unique number assigned.
See section 5.3.10 Number.
• If pump cables run parallel to each other, physically
separate them by 12-14 inches or rewire using
shielded cable.
Are the three CU 301 supply board LEDs in pos. 2, 3
and 4 on and is the control indicator LED flashing?
See section 4. Position of LEDs.
Yes:
• The mains supply is OK.
• Assign the system a new number.
If this does not work, the CU 301 or the motor commu-
nication part is defective.
Replace the CU 301 and give the new system a num-
ber between 1 and 64 in order to obtain correspon-
dence between the numbering of the SQE pump and
the CU 301.
Note: 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?
Yes: The CU 301 is OK. Go to point f).
No: The CU 301 which was removed is defective.
As a consequence of the above-mentioned checks,
replace the MSE 3 motor.
If an SQE/CU 301 system has been given a number,
this number is stored in both the SQE and CU 301.
A new CU 301 or SQE may not have a number corre-
sponding to the number stored in the previous unit.
Therefore, "No contact to pump" is indicated even if
there is no fault.
Give a new system the number between 1 and 64 in
order to obtain correspondence between the numbering
of the SQE pump and the CU 301.
Note: Two systems on the same mains supply must not
have the same number!
23