Maintenance And Inspection; Periodic Inspection - YASKAWA Varispeed L7 Instruction Manual

Maintenance and Inspection

Periodic Inspection

Check the following items during periodic maintenance.
The motor should not vibrate or make unusal noises.
•
There should be no abnormal heat generation from the Inverter or motor.
•
The ambient temperature should be within the Inverter's specifications.
•
The ouput current value shown in U1-30 should not be higher than the motor or the Inverter rated current
•
for extended period of time.
The cooling fan in the Inverter should be operating normally.
•
Before attempting any maintenance checks, make sure that the three-phase power is disconnected. With power
removed from the unit, the DC bus capacitors will stay charged for several minutes. The Charge LED in the
Inverter will glow red until the DC bus voltage is below 10VDC. To ensure that the DC bus is completely dis-
charged, 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.
External terminals
Mounting bolts
Connectors
Cooling fins
All PCBs
Input Diodes
Output Transistors
Power Modules
DC bus capacitors
Apply power to the Inverter and conduct the following inspection:
Cooling Fan(s)
-2
7
Fig 7.1 Periodic Inspections With no Power Applied
Item
Are all screws and bolts tight?
Are connectors tight?
Are the fins dirty or dusty?
Is there any conductive dirt or oil mist on
the PCBs?
Is there any conductive dirt or oil mist on
the modules or components?
Are there any irregularities, such as dis-
coloration or odour?
Fig 7.2 Periodic Inspections With Power Applied
Item
Is there any abnormal noise or vibration,
or has the toal operating time exceeded
20,000 hours.
Check U1-40 for the elapsed cooling oper-
ation time.
Inspection
Tighten loose screws and bolts firmly.
Reconnect the loose connectors.
Clean off any dirt and dust with an air gun using
dry air at a pressure of 4 x 10
(4 to 6 bar, 55 to 85 psi).
Clean off any dirt and dust with an air gun using
dry air at a pressure of 4 x 10
(4 to 6 bar, 55 to 85 psi).
Replace the boards if they cannot be made clean.
Clean off any dirt and dust with an air gun using
dry air at a pressure of 4 x 10
(4 to 6 bar, 55 to 85 psi).
Replace the capacitor or Inverter.
Inspection
http://nicontrols.com
Corrective Procedure
5 5
to 6 x 10 Pa
5 5
to 6 x 10 Pa
5 5
to 6 x 10 Pa
Corrective Procedure
Replace Cooling Fan