Mitsumi electronic H55K Marine Radio User Manual


 
39
Precautions for Maintenance and Inspection
PROTECTIVE FUNCTIONS
3
z Enclosure inside installation structure model
FR-CV-7.5K to 30K(-AT), FR-CV-H7.5K to H30K(-AT)
1) Disconnect the wiring of the power regeneration common converter unit.
2) Remove the screws in the L-bracket that fasten the cooling fan.
3) Unplugging the connector of the cooling fan removes the cooling fan from the unit.
4) Remove the L-bracket from the cooling fan to replace the cooling fan.
Reinstall the cooling fan so that the arrows of the fan point in the directions as shown above.
5) Reinstall it to the power regeneration common converter unit in the reverse procedure.
(2) Smoothing capacitors
A large-capacity aluminum electrolytic capacitor is used for smoothing the DC in the main circuit, and an aluminum
electrolytic capacitor is also used for stabilizing the control power in the control circuit. Their characteristics are
adversely affected by ripple current, etc. This is greatly influenced by the ambient temperature and operating
conditions. When the inverter is operated in on ordinary, air-conditioned environment, change the capacitors about
every 5 years.
Since the capacitors begin to deteriorate rapidly beyond a given period, check them at least once a year (desirably
every six months or less when they are approaching the end of their useful life).
Check the following:
1) Case (side faces and bottom face for expansion)
2) Sealing plate (for remarkable warping and extreme cracks)
3) Explosion-proof valve (for excessive valve expansion and operation)
4) Appearance, external cracks, discoloration, leakage. When the measured capacitance of the capacitor has
reduced below 85% of the rating, change the capacitor.
(3) Relays
To prevent a contact fault, etc., relays must be changed according to the number of accumulative switching times
(switching life).
Note: If the air flow is set in the wrong direction, the inverter life can be shorter.
Remove screws.
Unplug connector.
FR-CV Coolng fan
L-bracket