The Pump Runs But The Motor Protection Trips - Xylem Flygt 2840.180 Installation, Operation And Maintenance Manual

Troubleshooting
Cause
The self-holding function of the
contactor malfunctions.
If the problem persists, contact the local sales and service representative. Always state the
serial number of your product, see

The pump runs but the motor protection trips

WARNING:
Always disconnect and lock out power before servicing to prevent unexpected startup.
Failure to do so could result in death or serious injury.
NOTICE:
Do NOT override the motor protection repeatedly if it has tripped. Doing so may result in
equipment damage.
Cause
The motor protection is set too low.
The impeller is difficult to rotate by
hand.
The drive unit is not receiving full
voltage on all three phases.
The phase currents vary, or they are
too high.
The insulation between the phases
and ground in the stator is defective.
The density of the pumped fluid is too
high.
The ambient temperature exceeds the
maximum ambient temperature.
There is a malfunction in the overload
protection.
If the problem persists, contact the local sales and service representative. Always state the
serial number of your product, see
34
Remedy
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.
Product Description
Remedy
Set the motor protection according to the data plate and if applicable the
cable chart.
• Clean the impeller.
• Clean out the sump.
• Check that the impeller is properly trimmed.
• Check the fuses. Replace fuses that have tripped.
• If the fuses are intact, notify a certified electrician.
Contact the local sales and service representative.
1. Use an insulation tester. With a 1000 V DC megger, check that the
insulation between the phases and between any phase and ground is >
5 megohms.
2. If the insulation is less:
Contact the local sales and service representative.
Make sure that the maximum density is 1100 kg/m
• Change the impeller, or
• Change to a more suitable pump.
• Contact the local sales and service representative.
The pump must not be used for such an application.
Replace the overload protection.
Product Description
Flygt 2840.180 Installation, Operation, and Maintenance Manual
(page 9).
3
(9.2 lb/US gal)
(page 9).