Mitsubishi Electric Melservo MR-J3- 350B4, Instruction Manual

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13. SERVO AMPLIFIERS WITH A LARGE CAPACITY (30k TO 55kW)
13.2.2 Inspection
WARNING
Before starting maintenance and/or inspection, turn off the power and wait for 20
minutes or more until the charge lamp turns off. Then, confirm that the voltage
between L and L is safe with a voltage tester and others. Otherwise, an
electric shock may occur. In addition, always confirm from the front of the converter
unit whether the charge lamp is off or not.
CAUTION
Any person who is involved in inspection should be fully competent to do the work.
Otherwise, you may get an electric shock. For repair and parts replacement,
contact your safes representative.
POINT
Do not test the converter unit drive unit with a megger (measure insulation
resistance), or it may become faulty.
It is recommended to make the following checks periodically:
1) Check for loose terminal block screws. Retighten any loose screws.
2) Check the servo motor bearings, brake section, etc. for unusual noise.
3) Check the cables and the like for scratches and cracks. Perform periodic inspection according to operating
conditions.
4) Check the servo motor shaft and coupling for misalignment.