7-2
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.
Apply power to the Inverter and conduct the following inspection:
Fig 7.1 Periodic Inspections With no Power Applied
Item Inspection Corrective Procedure
External terminals
Mounting bolts
Connectors
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
dry air at a pressure of 4 x 10
5
to 6 x 10
5
Pa
(4 to 6 bar, 55 to 85 psi).
All PCBs
Is there any conductive dirt or oil mist on
the PCBs?
Clean off any dirt and dust with an air gun using
dry air at a pressure of 4 x 10
5
to 6 x 10
5
Pa
(4 to 6 bar, 55 to 85 psi).
Replace the boards if they cannot be made clean.
Input Diodes
Output Transistors
Power Modules
Is there any conductive dirt or oil mist on
the modules or components?
Clean off any dirt and dust with an air gun using
dry air at a pressure of 4 x 10
5
to 6 x 10
5
Pa
(4 to 6 bar, 55 to 85 psi).
DC bus capacitors
Are there any irregularities, such as dis-
coloration or odour?
Replace the capacitor or Inverter.
Fig 7.2 Periodic Inspections With Power Applied
Item Inspection Corrective Procedure
Cooling Fan(s)
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.
Replace Cooling Fan
http://nicontrols.com
To Next Page
Loading...
Need help?
General