7.2 Inspection
7.2
Inspection
Power electronics have limited life and may exhibit changes in characteristics or performance deterioration after years of
use under normal conditions. To help avoid such problems, it is important to perform preventive maintenance and
periodic inspection on the drive.
Drives contain a variety of power electronics such as power transistors, semiconductors, capacitors, resistors, fans, and
relays. The electronics in the drive serve a critical role in maintaining proper motor control.
Follow the inspection lists provided in this chapter as a part o f a regular maintenance program.
Note:
The drive will require more frequent inspection if it is placed in harsh environments, such as:
• High ambient temperatures
• Frequent starting and stopping
• Fluctuations in the AC supply or load
• Excessive vibrations or shock loading
• Dust, metal dust, salt, sulfuric acid, chlorine atmospheres
• Poor storage conditions.
Perform the first equipment inspection one to two years after installation.
♦ Recommended Daily Inspection
Table 7.1
outlines the recommended daily inspection for Yaskawa drives. Check the following items on a daily basis to
avoid premature deterioration in performance or product failure. Copy this checklist and mark the “Checked” column
after each inspection.
Table 7.1 General Recommended Daily Inspection Checklist
Inspection Category
Inspection Points
Corrective Action
Checked
M o t o r
Inspect for abnormal oscillation or noise com ing from the motor.
• Check the load coupling.
• Measure motor vibration.
• Tighten all loose components.
C o o l i n g
Inspect for abnormal heat generated from the drive or motor and
visible discoloration.
Check for excessive load.
• E xcessive load.
• L oose connections.
• Dirty heatsink or motor.
• Am bient temperature.
Inspect drive cooling fan operation.
Check for the following:
• C logged or dirty fan.
• Correct fan operation parameter setting.
E n v i r o n m e n t
Verify the drive environment com plies w ith the specifications listed
in Installation E n viro n m en t on p a g e 3 5 .
Eliminate the source o f contaminants or correct poor
environment.
L o a d
The drive output current should not be higher than the motor or drive
rating for an extended period o f time.
Check for the following:
• E xcessive load.
• Correct motor parameter settings.
P o w e r S u p p l y V o l t a g e
Check main power supply and control voltages.
• Correct the voltage or power supply to within nameplate
specifications.
• Verify all main circuit phases.
YASKAWA ELECTRIC SIEP C710616 33D YASKAWA AC Drive L1000A Technical Manual
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