Built-In Protection; Maintenance And Service; Contaminated Pumps - Grundfos SQ Installation And Operating Instructions Manual

Example:
p = 35 m head, Q = 2.5 m³/h.
min max
On the basis of this information, the following values can be found in the table:
Minimum diaphragm tank size = 33 litres.
p = 31.5 m head.
pre
p = 36 m head.
cut-in
p = 50 m head.
cut-out
p
min
0.6 0.8 1 1.2 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8
[m]
25 8 8 18 18 18 18 24 33 33 50 50 50 50 80 80 80 80 80
30 8 8 18 18 18 24 33 33 50 50 50 50 80 80 80 80 80
35 8 18 18 18 18 24 33 33 50 50 50 80 80 80 80 80
40 8 18 18 18 18 24 33 50 50 50 80 80 80 80 80
45 8 18 18 18 24 33 33 50 50 50 80 80 80 80
50 8 18 18 18 24 33 50 50 50 80 80 80 80
55 18 18 18 18 24 33 50 50 50 80 80 80
60 18 18 18 18 24 33 50 50 80 80 80 80
65 18 18 18 24 24 33 50 50 80 80 80 80
1 m head = 0.098 bar.

7.3 Built-in protection

The motor incorporates an electronic unit which
protects the motor in various situations.
In case of overload, the built-in overload protection
will stop the pump for 5 minutes. After that period,
the pump will attempt to restart.
If the pump has been stopped as a result of dry
running, it will start automatically after 5 minutes.
If the pump is restarted and the borehole is empty,
the pump will stop after 30 seconds.
Resetting of the pump: Switch off the electricity
supply for 1 minute.
The motor is protected in case of:
• dry running,
• voltage surges (up to 6000 V),
In areas with high lightning intensity, external
lightning protection is required.
• overvoltage,
• undervoltage,
• overload and
• overtemperature.
SQE pumps/MSE 3 motors:
Note: Via the CU 300 or CU 301, the dry-running
stop limit of the MSE 3 motors can be adjusted to
match the actual application.
14
Q [m³/h]
max
Diaphragm tank size [litres]

8. Maintenance and service

The pumps are normally maintenance-free.
Deposits and wear may occur. For that purpose,
service kits and service tools are available from
Grundfos. The Grundfos Service Manual is available
on request.
The pumps can be serviced at a Grundfos service
centre.

8.1 Contaminated pumps

Note: If a pump has been used for a liquid which is
injurious to health or toxic, the pump will be
classified as contaminated.
If Grundfos is requested to service the pump,
Grundfos must be contacted with details about the
pumped liquid, etc. before the pump is returned for
service. Otherwise Grundfos can refuse to accept
the pump for service.
However, any application for service (no matter to
whom it may be made) must include details about
the pumped liquid if the pump has been used for
liquids which are injurious to health or toxic.
SQE-NE: Only pumps that can be certified as
uncontaminated, i.e. pumps containing no hazardous
and/or toxic material, may be returned to Grundfos
for servicing.
To prevent injury to the health of persons involved
and to the environment, a document certifying that
the pump is clean is required.
Grundfos must receive this certificate before the
product. Otherwise, Grundfos will refuse to accept
the product for servicing.
Possible costs of returning the pump are paid by the
customer.
p p p
pre cut-in cut-out
[m] [m] [m]
22.5 26 40
27 31 45
31.5 36 50
36 41 55
40.5 46 60
45 51 65
49.5 56 70
54 61 75
58.5 66 80