7.2 Inspection
Power electronics have limited life and may exhibit changed 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, semi-conductors, 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 of 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 3 months after installation.
u
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.
WARNING! Electrical Shock Hazard. Do not connect or disconnect wiring while the power is on. Failure to comply can result in serious personal injury. Before servicing the drive,
disconnect all power to the equipment. The internal capacitor remains charged even after the power supply is turned off. The charge indicator LED will extinguish when the DC bus
voltage is below 50 Vdc. To prevent electric shock, wait at least five minutes after all indicators are OFF and measure the DC bus voltage level to confirm safe level.
Table 7.1 General Recommended Daily Inspection Checklist
Inspection Category Inspection Points Corrective Action Checked
Motor • Inspect for abnormal oscillation or noise coming from the motor.
• Check the load coupling
• Measure motor vibration
• Tighten all loose components
Cooling
• Inspect for abnormal heat generated from the drive or motor and
visible discoloration.
• Check for excessive load
• Loose connections
• Check for dirty heatsink or motor
• Ambient temperature
Cooling • Inspect drive cooling fan operation.
• Check for clogged or dirty fan.
• Check fan operation drive parameter.
Environment
• Verify the drive environment complies with the specifications listed
in the Installation section of this manual.
• Eliminate the source of contaminants or correct poor
environment.
Load
• The drive output current should not be higher than the motor or drive
rating for an extended period of time.
• Check for excessive load.
• Check the motor parameter settings of the drive.
Power Supply Voltage • Check main power supply and control voltages.
• Correct the voltage or power supply to within nameplate
specifications.
• Verify all main circuit phases.
u
Recommended Periodic Inspection
Table 7.2 outlines the recommended periodic inspections for Yaskawa drive installations. Periodic inspections should generally be checked every 3-6
months; however, the drive may require more frequent inspection due to poor environments or rigorous use. Operating and environmental conditions,
along with experience in each application, will determine the actual inspection frequency for each installation. Periodic inspection will help to avoid
premature deterioration in performance or product failure. Copy this checklist and mark the “Checked” column after each inspection.
n
Periodic Inspection
WARNING! Electrical Shock Hazard. Do not connect or disconnect wiring while the power is on. Failure to comply can result in serious personal injury. Before servicing the drive,
disconnect all power to the equipment. The internal capacitor remains charged even after the power supply is turned off. The charge indicator LED will extinguish when the DC bus
voltage is below 50 Vdc. To prevent electric shock, wait at least five minutes after all indicators are OFF and measure the DC bus voltage level to confirm safe level.
Table 7.2 Periodic Inspection Checklist
Inspection Area Inspection Points Corrective Action Checked
Main Circuit Periodic Inspection
General
• Overall check of the main power circuit and ground terminals Take appropriate actions (e.g., tightening loose connections).
• Inspect equipment for discoloration from overheating or
deterioration.
• Inspect for damaged or deformed parts.
• Replace damaged components as required.
• The drive has few serviceable parts and may require complete
drive replacement.
• Inspect for dirt, foreign particles, or dust collection on components.
• Inspect enclosure door seal if present. Replace components if
cleaning is not possible.
• Use dry air to clear away foreign matter. Use a pressure of 39.2
x 10
4
to 58.8 x 10
4
Pa (4 - 6 kg •cm
2
).
Conductors and Wiring
• Inspect wiring and connections for discoloration, damage, or heat
stress.
• Inspect wire insulation and shielding for wear.
• Repair or replace damaged wiring.
Terminals • Inspect terminals for stripped, damaged, or loose connections. • Tighten loose screws and replace damaged screws or terminals.
7.2 Inspection
258
YASKAWA ELECTRIC SIEP C710606 18A YASKAWA AC Drive – V1000 Technical Manual (Preliminary)
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