Mitsubishi FR-A800

Inspection item
682
PRECAUTIONS FOR MAINTENANCE AND INSPECTION
Smoothing capacitors
A large-capacity aluminum electrolytic capacitor is used for smoothing in the main circuit DC section, and an aluminum
electrolytic capacitor is used for stabilizing the control power in the control circuit. Their characteristics are deteriorated by the
adverse effects of ripple currents, etc. The replacement intervals greatly vary with the surrounding air temperature and
operating conditions. When the inverter is operated in air-conditioned, normal environment conditions, replace the capacitors
about every 10 years.
The appearance criteria for inspection are as follows:
• Case: Check the side and bottom faces for expansion.
• Sealing plate: Check for remarkable warp and extreme crack.
• heck for external crack, discoloration, liquid leakage, etc. Judge that the capacitor has reached its life when the measured
capacitance of the capacitor reduced below 80% of the rating.
NOTE
• The inverter diagnoses the main circuit capacitor and control circuit capacitor by itself and can judge their lives. (Refer to
page 278.)
Relays
To prevent a contact fault, etc., relays must be replaced according to the cumulative number of switching times (switching life).
Main circuit fuse inside the inverter (FR-A840-04320(160K) or higher)
A fuse is used inside the inverter. Surrounding air temperature and operating condition affect the life of fuses. When the
inverter is used in a normal air-conditioned environment, replace its fuse after about 10 years.
7.1.7 Inverter replacement
The inverter can be replaced with the control circuit wiring kept connected. Before replacement, remove the wiring cover of
the inverter.
1) Loosen the two mounting screws at the both side of the control circuit terminal block. (These screws cannot be removed.)
Slide down the control circuit terminal block to remove it.
2) Be careful not to bend the pins of the inverter's control circuit connector, reinstall the control circuit terminal block and fix it
with the mounting screws.
NOTE
• Before starting inverter replacement, switch power OFF, wait for at least 10 minutes, and then check the voltage with a tester
and such to ensure safety.
Loosen the
screws
Fix it with
the screws