Mitsubishi 700 Series Instruction Manual page 131

Inspection items
(1) Cooling fan
The replacement interval of the cooling fan used for cooling the parts generating heat such as the main circuit semiconductor
is greatly affected by the surrounding air temperature. When unusual noise and/or vibration is noticed during inspection, the
cooling fan must be replaced immediately.
Removal
1) Push the hooks from above and remove the fan
cover.
3.7K or less
2) Disconnect the fan connectors.
3) Remove the fan.
3.7K or less
Example for FR-D740-1.5K
122
Fan cover
Fan connector
Fan
5.5K or more
5.5K or more
Example for FR-D740-7.5K
Fan cover
Fan
Fan connector