1
8
Start-up
•
Disconnect the motor from the mains.
•
Remove the priming plug located on the upper part of the pump body.
Figure 17.
•
Pour liquid through the delivery pipe until it overflows through the
priming hole.
•
While priming, rotate the pump shaft by hand to break any sticking.
•
Replace the priming plug in its position.
Never run a pump dry. Most centrifugal pumps have a mechanical seal or stuffing box, therefore they cannot be run dry
under any working conditions, otherwise the sealing elements will be seriously damaged.
Before starting the pump, the suction pipe must be completely filled with the fluid to be pumped, this allows the pump to
start always primed and prevents the accumulation of air in the suction system. The procedure is as follows:
6.2
Pump Priming
6.3
Minimum Flow Rate
It must be taken into account that there is a minimum flow rate at which the pump must work, which is given by the
temperature of the pumped fluid, according to the following table.
0 < T < 50 ºC => 20% of the maximum efficiency point flow rate.
50 < T < 80 ºC => 30% of the maximum efficiency point flow rate.
6.4
Pumped Fluid Density
The power required for pump operation increases directly with the density of the pumped fluid. In order not to overload the
electric motor, it must be ensured that the pumped fluid corresponds to that which was originally considered for the
selection of the pump and its motor.
!
CAUTION
Start-up
6.1
Before start-up
After a pump has been installed and all mechanical, hydraulic and electrical connections have been made, it is ready for
commissioning. However, prior to initial start-up, the following is recommended:
Figur
e
17