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INSTRUCTION MANUAL
5.2 Checking Rotation Direction (Figs. 18 and 19)
Check the motor for rotation direction by the following procedure after the pump has
been installed in the pump pit.
A reversing pump is no problem if operation is not prolonged.
(1)
PM32U
If the pump performance curve is available.
Open the sluice valve on the discharge side approximately half a turn (so
that air is released and a small quantity of liquid is discharged), and turn the
main switch ON. With all air released from the discharge pipe, fully close the
sluice valve.
As this time, if the value of shut-off head (H1 + H2) (ft),
where
H1 (ft)
Compound pressure gauge reading
H2 (ft)
Vertical distance from gauge to liquid surface
is generally in agreement with the pump performance at hand, the pump is
operating normally.
If the pump is reversed, a performance curve as denoted by dashed lines in
Fig. 18 is usually obtained, where the pump's discharge pressure is lower
than normal or specified, and a sudden rise electric current occurs with
gradual opening of sluice valve.
In this event, change connections as shown in Fig. 19.
Fig. 18 Pump performance for Normal Rotation
P.20
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