Hitachi J300U Series - Manual (Page 82)

10-1
10. MAINTENANCE AND INSPECTION
10.1 Maintenance and Inspection Precautions
WARNING
* Be sure to turn off the power supply during maintenance and inspection.
* After the power supply has been turned off, you must always wait 10 minutes so that
DC bus capacitors can discharge then start maintenance and inspection after the
CHARGE lamp on the printed-circuit board has gone out. (Immediately after the lamp
has gone out, there will be a residual voltage of about 50 V DC in the DC bus
intermediate circuit.)
Perform the work after the CHARGE lamp has stopped flickering.
* Make sure that only qualified persons will perform maintenance, inspection and part
replacement. (Before starting the work, remove metallic objects from your person
(wristwatch, bracelet, etc.)
(Be sure to use tools protected with insulation.)
Otherwise, there is a danger of electric shock and/or injury.
CAUTION
* When removing connectors, never pull the wires. (Wires for cooling fan and thermal
relay)
Otherwise, there is a danger of fire due to wire breakage and/or injury.
• General precautions
Always keep the unit clean so that dust or other foreign matter does not enter the inverter.
Take special care in regard to breaking lines and connection mistakes. Firmly connect
terminals and connectors. Keep electronic equipment away from moisture and oil. Dust,
steel filings and other foreign matter can damage insulation, causing unexpected accidents,
so take special care.
10.2 Inspection Items
(1) Daily inspection
(2) Periodic inspection (Approximately once a year)
See 10-3.
(3) Insulation resistance tests, withstand voltage tests