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 a remarkable warp and extreme crack.
• Check for an 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.
• The inverter diagnoses the main circuit capacitor and control circuit capacitor by itself and can judge their lives. (Refer to
For relay output terminal
• To prevent a contact fault, etc., relays must be replaced according to the cumulative number of switching times (switching
• The control terminal block must be replaced (refer to
terminals C1 and B1 or A1, or terminals C2 and B2 or A2. (After replacing the control terminal block, connect the jumper
connector to the correct position in accordance with the control logic of input signals. (Refer to
Main circuit fuse inside the inverter (FR-F840-04320(185K) or higher)
Fuses are used in some inverters. The 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. PRECAUTIONS FOR MAINTENANCE AND INSPECTION
7.1 Inspection item
605) in case of failure of either relay between the relay output