Xylem FHF SHF - Manual (Page 20)

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5.5.2 Pipe clamping
FIG. 1 FIG. 2
Correct installation Incorrect installation
A = Eccentric reductions 1 = Sharp bend: high flow resistance
B = Positive gradient 2 = Insufficient immersion: sucking air
C = Good immersion 3 = Positive gradient: air pockets
D = Large bends 4 = Pipe diameter < pump port
E = Suction pipe diameter ≥ pump port diameter diameter: high flow resistance
F = Suction lift depends on the pump and
installation (*). In normal conditions this
should not exceed 5-6 m
G = Suction lift depends on the pump and
installation
(*) Suction lift is determined based on liquid temperature, elevation, flow resistance and NPSH required by the pump.
A few pump models, at the highest capacity allowed, have a high NPSH requirement and therefore, under particular operating
conditions, the maximum suction lift may be limited or even such as to require installation below the head. In such cases carefully check
the suction conditions to avoid operating problems (cavitation).
6. Start-up
The pump must run smoothly and quietly. Avoid long running with the delivery gate valve closed. Always
drain the pump whenever it remains inactive at freezing temperatures.
6.1 Electrical connections
Make sure that the rated voltage corresponds to the supply voltage.
Ground the pump before making any other connection.
We recommend that a high sensitivity differential switch (30 mA) be installed as extra
protection against lethal electric shocks in the event of faulty grounding.
Remove the terminal board cover by first removing the screws.
Carry out the connections as indicated on the back of the terminal board cover, and as shown in fig. 3 -4.
WARNING
001073145_L_F_02-11:001073145_L_E_12-10 21-02-2011 16:44 Pagina 20