Grundfos SP Serie Instrucciones De Instalación Y Funcionamiento página 22

9. Startup and operation
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 accidental-
ly switched on.
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 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 Positional requirements
and fig. Comparison of various water levels.
L3
L2
L1
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.
22
L4
L5
Long time of operation with water containing air may dam-
age the pump and cause insufficient cooling of the motor.
Related information
5.2 Positional requirements
6.6 Connection of three-phase motors
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 Liquid temperatures and motor cooling cannot be met.
Related information
5.4 Liquid temperatures and motor cooling
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
Motor type
MS402
MS4000
MS6000
MS6000P
PVC windings
MMS6
PE/PA windings
PVC windings
MMS8000
PE/PA windings
Number of starts
Grundfos recommends mini-
mum 1 per year.
Maximum 100 per hour.
Maximum 300 per day.
Grundfos recommends mini-
mum 1 per year.
Maximum 100 per hour.
Maximum 300 per day.
Grundfos recommends mini-
mum 1 per year.
Maximum 30 per hour.
Maximum 300 per day.
Grundfos recommends mini-
mum 1 per year.
Maximum 120 per hour.
Maximum 360 per day.
Grundfos recommends mini-
mum 1 per year.
Maximum 3 per hour.
Maximum 40 per day.
Grundfos recommends mini-
mum 1 per year.
Maximum 10 per hour.
Maximum 70 per day.
Grundfos recommends mini-
mum 1 per year.
Maximum 3 per hour.
Maximum 30 per day.
Grundfos recommends mini-
mum 1 per year.
Maximum 8 per hour.
Maximum 60 per day.