6-1
6. Troubleshooting
If you find any abnormal conditions of the pump, carefully investigate the problem. For overhaul,
replacement of the parts or repairs, ask the vendor or contact Teral or our servicing companies.
Problem
Cause (Reference page)
Action (Reference page)
Wiring is disconnected or broken.
Check the wires and connections to repair or
replace.
Poor connection or contact of power wires
(3-7)
Check by a tester and replace the defects with a
good one if any.
The power fuse is blown.
Replace it with an appropriate fuse.
Tripping of the thermal relay
Check the thermal relay.
The power voltage is too low. (2-2)
Check the power voltage and contact the power
company.
The motor has failed.
Foreign matter is caught in the impeller.
The shaft seal is bound.
The pump does not
start.
The bearing is rusty.
Contact Teral or our servicing companies because
disassembly and inspection are required.
The priming in the casing is not enough.
(4-1)
Fully prime the water.
The pumping liquid contains many bubbles. Prevent the formation and suction of bubbles.
The air intrudes from the suction piping.
Check the joint of each suction piping.
The rotation direction is reverse. (4-2)
Correct the wiring so that the motor rotates in
normal direction. (4-2)
The piping loss is high.
Check the diameter, route and length of the pipes.
The piping is clogged with foreign matter.
Check and clean the piping.
The impeller and the liner ring are worn.
Foreign matter is accumulated in the
impeller and in the casing.
Contact Teral or our servicing companies because
disassembly and inspection are required.
The rotation speed is low.
Check with the tachometer.
The sluice valve is closed. (4-3)
Open the sluice valve.
There is a leak in the discharge pipe.
Check and repair the pipe.
The pump starts, but
cannot achieve the
specified discharge
rate and the
specified head.
The total suction head is too high. (2-2)
Consult us or our servicing companies.
The rotation speed is too high.
Check with the tachometer.
The stator winding is broken, shorted, or
grounded.
The stator and rotor are in contact due to
wear of the bearing.
Contact Teral or our servicing companies because
disassembly and inspection are required.
The motor is running in open-phase
condition.
Check the wiring.
The setting of overload protection device is
too low.
Correctly set the motor overload protection device.
The power supply voltage is out of the
allowable fluctuation range.(2-2)
Check the voltage and contact the power company.
A 50Hz pump is run in the 60Hz power
zone.
Check the nameplate.
The discharge rate is high.
Throttle the sluice valve to adjust the rate as per the
specifications.
A rotating part is in contact with another
part.
Foreign objects enter into the pump.
Contact Teral or our servicing companies because
disassembly and inspection are required.
Overload and
overcurrent of the
motor
The gland packing is excessively tightened.
Properly adjust the drip rate from the gland packing
(5-3).
