English (GB)
15
9. Startup and operation
9.1 Startup
When the pump has been connected correctly and it is
submerged in the liquid to be pumped, it must be started with the
outlet valve closed off to approximately 1/3 of its maximum
volume of water.
Check the direction of rotation as described in section
6.6 Connection of three-phase motors
If there are impurities in the water, open the valve gradually as
the water becomes clearer. Do not stop the pump until the water
is completely clean, as otherwise the pump parts and the
non-return valve may become blocked.
As the valve is being opened, check the drawdown of the water
level to ensure that the pump always remains submerged.
The dynamic water level must always be above the suction
interconnector of the pump. See section
and fig.
Fig. 24
Comparison of various water levels
L1: Minimum installation depth below dynamic water level. We
recommend minimum 0.5 m or according to NPSH - curve for
the relevant pump.
L2: Depth to dynamic water level.
L3: Depth to static water level.
L4: Drawdown. This is the difference between the dynamic and
the static water levels.
L5: Installation depth.
If the pump can pump more than yielded by the well, we
recommend that you install the Grundfos MP 204 motor protector
or some other type of dry-running protection.
If no water level electrodes or level switches are installed, the
water level may be drawn down to the suction interconnector of
the pump and the pump will then draw in air.
9.2 Operation
9.2.1 Minimum flow rate
To ensure the necessary cooling of the motor, the pump flow
velocity must never be set so low that the cooling requirements in
section
5.4 Liquid temperatures and motor cooling
cannot be met.
9.2.2 Operating range
The pump must never run outside the rated pump curve - see
Data Booklet.
9.2.3 Frequency of starts and stops
DANGER
Electric shock
Death or serious personal injury
- The pump must be connected to protective earth.
- Switch off the power supply before starting any
work on the product.
- Make sure that the power supply cannot be
accidentally switched on.
TM
00
10
4
1
36
95
L2
L3
L1
L5
L4
Long time of operation with water containing air may
damage the pump and cause insufficient cooling of
the motor.
Motor type
Number of starts
MS402
• Grundfos recommends
minimum 1 per year.
• Maximum 100 per hour.
• Maximum 300 per day.
MS4000
• Grundfos recommends
minimum 1 per year.
• Maximum 100 per hour.
• Maximum 300 per day.
MS6000
• Grundfos recommends
minimum 1 per year.
• Maximum 30 per hour.
• Maximum 300 per day.
MS6000P
• Grundfos recommends
minimum 1 per year.
• Maximum 120 per hour.
• Maximum 360 per day.
MMS6
PVC windings
• Grundfos recommends
minimum 1 per year.
• Maximum 3 per hour.
• Maximum 40 per day.
PE/PA windings
• Grundfos recommends
minimum 1 per year.
• Maximum 10 per hour.
• Maximum 70 per day.
MMS8000
PVC windings
• Grundfos recommends
minimum 1 per year.
• Maximum 3 per hour.
• Maximum 30 per day.
PE/PA windings
• Grundfos recommends
minimum 1 per year.
• Maximum 8 per hour.
• Maximum 60 per day.
MMS10000
PVC windings
• Grundfos recommends
minimum 1 per year.
• Maximum 2 per hour.
• Maximum 20 per day.
PE/PA windings
• Grundfos recommends
minimum 1 per year.
• Maximum 6 per hour.
• Maximum 50 per day.
MMS12000
PVC windings
• Grundfos recommends
minimum 1 per year.
• Maximum 2 per hour.
• Maximum 15 per day.
PE/PA windings
• Grundfos recommends
minimum 1 per year.
• Maximum 5 per hour.
• Maximum 40 per day.
