Yaskawa F7 Drive User Manual - Manual (Page 159)

Maintenance 7 - 2
Periodic Inspection
Check the following items during periodic maintenance.
• The motor should not be vibrating or making unusual noises.
• There should be no abnormal heat generation from the Drive or motor.
• The ambient temperature should be within the Drive specification of -10
°C to 40°C (14°F to 104°F).
• The output current value shown on U1-03 should not be higher than the motor or Drive rated current for an extended period
of time.
• The cooling fan in the Drive should be operating normally.
Before attempting any maintenance checks, make sure that the three-phase power is disconnected and locked out. With power
removed from the unit, the DC bus capacitors will stay charged for several minutes. The Charge LED in the Drive will glow
red until the DC bus voltage is below 10Vdc. To ensure that the DC bus is completely discharged, measure between the
positive and negative bus with a DC voltmeter set to the highest scale. Be sure not to touch terminals immediately after the
power has been turned off. Doing so can result in electric shock. Please refer to Warnings starting on page i.
Apply power to the Drive and conduct the following inspection.
Table 7.1 Periodic Inspections With no Power Applied
Item Inspection Corrective Action
External terminals, mount-
ing bolts,
connectors, etc.
Are all screws and bolts tight? Tighten loose screws and bolts firmly.
Are connectors tight? Reconnect the loose connectors.
Cooling fins Are the fins dirty or dusty?
Clean off any dirt and dust with an air gun using clean and dry
air at a pressure between 55-85 psi.
Control PCB
Terminal PCB
Power PCB
Gate Drive PCBs
Is there any conductive dirt or oil mist on
the PCBs?
Clean off any dirt and dust with an air gun using clean and dry
air at a pressure between 55-85 psi. Replace the boards if they
cannot be made clean.
Input Diodes
IPMs
Output Transistors
Is there any conductive dirt or oil mist on
the modules or components?
Clean off any dirt and dust with an air gun using clean and dry
air at a pressure between 55-85 psi.
Replace the boards if they cannot be made clean.
DC bus capacitors
Are there any irregularities, such as
discoloration or odor?
Replace the capacitors or Drive.
Table 7.2 Periodic Inspections With Power Applied
Item Inspection Corrective Action
Cooling fan(s)
Is there any abnormal noise or vibration, or has the
total operating time exceeded 20,000 hours. Check
U1-40 for elapsed cooling fan operation time.
Replace Cooling Fan