Fire pump group start is a light load in terms of prime mover start, under normal circumstances will not start any problem. However, for some large units, due to the inertia of the unit, starting difficult, start a larger start current, pay attention to start the way, then the power grid or motor damage. Therefore, the start-up characteristics of different types of pumps should be taken seriously.
1, the starting characteristics of the vortex pump – open the valve to start
Vortex pump in the zero flow conditions, the largest shaft power, rated shaft power of 130% to 190%, so with the axial pump is similar to the start of the vortex pump should be a large flow start (that is, full-open valve start).
2, the large flow of axial flow pump start characteristics – open the valve to start
Axial flow pump in the zero flow conditions when the shaft power of the largest, for the rated shaft power of 140% to 200%, maximum flow power minimum, so in order to start the current minimum, shaft power starting characteristics should be large flow start Valve activation).
3, mixed-flow pump start-up characteristics – fully open the valve to start
Mixed-flow pump in the zero-flow conditions between the shaft power between the two pumps, the rated power of 100% to 130%, so mixed-flow pump start-up characteristics should be between the two pumps, the best fully open valve start up.
4, zero-flow start-up characteristics of centrifugal pumps – off valve to start
Centrifugal pump in the zero flow conditions when the shaft power of the smallest, for the rated shaft power of 30% to 90%, so the start-up characteristics of centrifugal pump is zero flow start (that is, off valve start). Until the pump to the rated speed after the discharge valve can be adjusted to flow rated point.