Maintenance And Inspection; Periodic Inspection - Omron VARISPEED L7 Manual

Maintenance and Inspection

Periodic Inspection

Check the following items during periodic maintenance.
The motor should not vibrate or make unusual noises.
•
There should be no abnormal heat generation from the Inverter or motor.
•
The ambient temperature should be within the Inverter's specifications.
•
The output current value shown in U1-03 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 light 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. Be sure not to touch terminals
immediately after the power has been turned off. Doing so can result in electric shock.
Item
External terminals
Mounting bolts connectors
Cooling fins
All PCBs
Input Diodes
Output Transistors Power
Modules
8
DC bus capacitors
Cooling Fan(s)
2
8-
Table 8.1 Periodic Inspections
Inspection
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 discoloration
or odor?
Is there any abnormal noise or vibration, or has
the total operating time exceeded 20,000 hours.
Check U1-40 for the elapsed cooling operation
time.
Corrective Procedure
Tighten loose screws and bolts firmly.
Reconnect the loose connectors.
Clean off any dirt and dust with an air gun using dry air at
5 5
a pressure of 4 x 10 to 6 x 10 Pa
(4 to 6 bar, 55 to 85 psi).
Clean off any dirt and dust with an air gun using dry air at
5 5
a pressure of 4 x 10 to 6 x 10 Pa
(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
5 5
a pressure of 4 x 10 to 6 x 10 Pa
(4 to 6 bar, 55 to 85 psi).
Replace the capacitor or Inverter.
Replace Cooling Fan