Maeda MC305C-3 - Electric Motor

Section 5 – TROUBLESHOOTING Mini-Crawler Crane M A E D A
5-88 3/2019 MC305C-3
Electric Motor
Abnormal Phenomenon
Major Cause(s)
Actions
The motor remains off despite the
switch being turned to the
"START" position.
• Improper wiring and power
supply error
• The Inverter unit breakers: OFF
• A break in stator winding
• Check wiring, see "ELECTRIC
MOTOR OPERATION" on page
4-122.
• Turn ON the breakers.
(• Inspection, repair, replacement)
(• Inspection, repair, replacement)
The motor comes to a stop during
use.
• Inverter unit error
(Red lamp: ON)
• Failure in the Inverter unit
• Failure in the power unit
• Check the power supply source
(voltage and phase interruption).
(• Inspection, repair, replacement)
(• Inspection, repair, replacement)
The power output of the motor
reaches zero or undergoes
gradual decrease.
• Phase interruption in the power
source of power supply
equipment
• Slack in motor wiring
• Check the power source of
power supply equipment (voltage
and phase interruption).
• Inspect connection with the
motor Terminal block.
(• Inspection, repair, replacement)
The cabtyre cable rises in
temperature.
• Considerable voltage drop
• Ensure that the power supply
voltage of power supply
equipment is at a specified value.
• Replace the cabtyre cable with
one adhering to specifications.
An abnormal noise and vibration
are present in the power unit
during operation.
• A break in motor winding
• Looseness in the motor and
pump fixing bolt
• Looseness in the coupling fixing
bolt
• Impurities on the coupling
• Clogging in the hydraulic oil tank
strainer and element
• Inspect the motor Terminal
block.
(• Inspection, repair, replacement)
• Perform inspection, repair, and
cleaning. See "ELECTRIC
MOTOR OPERATION" on page
4-122.
(• Replacement)
• Clean and replace the strainer
and element according to
periodic inspection.
The power unit rises in
temperature during operation.
• High ambient temperature
• Ill-ventilated
• Considerable voltage drop
• Overload
• High number of starts
• Use the power unit in
environment compliant with
specifications.
• Perform inspection and
cleaning, See "ELECTRIC
MOTOR OPERATION" on page
4-122.
• Replace the cabtyre cable with
one adhering to specifications.
• Reduce loads.
• Reduce the number of starts.
The leak detector of the Inverter
unit main breaker is tripped.
• High humidity
• Presence of water droplets
• Ill-grounded
• A break in stator winding
• Use the leak detector in
environment compliant with
specifications.
• Attach the cover properly.
• Adhere to ground standards.
(• Inspection, repair, replacement)
The trouble lamp (red) of the
Inverter unit comes on.
• Failure in the Inverter unit
(• Inspection, repair, replacement)