Xylem Flygt 2008 Ready 8, Installation, Operation And Maintenance Manual

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7.3 The pump starts-stops-starts in rapid sequence
Cause Remedy
The pump starts due to back-flow
which fills the sump to the start level
again.
Check that:
• The distance between the start and stop levels is sufficient.
• The non-return valve(s) work(s) properly.
• The length of the discharge pipe between the pump and the first non-
return valve is sufficiently short.
The self-holding function of the
contactor malfunctions.
Check:
• The contactor connections.
• The voltage in the control circuit in relation to the rated voltages on the
coil.
• The functioning of the stop-level regulator.
• Whether the voltage drop in the line at the starting surge causes the
contactor's self-holding malfunction.
If the problem persists, then contact a sales or authorized service representative.
Always state the serial number of the product, see
Product Description on page 8.
7.4 The pump runs but the motor protection trips
DANGER: Crush Hazard
Moving parts can entangle or crush. Always disconnect and lock out power before
servicing to prevent unexpected startup. Failure to do so could result in death or serious
injury.
Equipment
locked
out
by
Name
.......................
DANGER
NOTICE:
Do NOT override the motor protection repeatedly if it has tripped. Doing so may result in
equipment damage.
Cause Remedy
The motor protection is set too low. Set the motor protection according to the data plate and if applicable the
cable chart.
The impeller is difficult to rotate by
hand.
• Clean the impeller.
• Clean out the sump.
• Check that the impeller is properly trimmed.
The drive unit is not receiving full
voltage on all three phases.
• Check the fuses. Replace fuses that have tripped.
• If the fuses are intact, then notify a certified electrician.
The phase currents vary, or they are
too high.
Contact a sales or authorized service representative.
7 Troubleshooting
2008 Ready 8, 8S Installation, Operation, and Maintenance 33