Inverter Replacement - Mitsubishi Electric FR-A700 Series Instruction Manual

Inspection item
(3) 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 ambient 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:
1) Case: Check the side and bottom faces for expansion
2) Sealing plate: Check for remarkable warp and extreme crack.
3) Check for external crack, discoloration, fluid leakage, etc. Judge that the capacitor has reached its life when the
measured capacitance of the capacitor reduced below 80% of the rating.
Refer to page 152 to perform the life check of the main circuit capacitor.
(4) Relays
To prevent a contact fault, etc., relays must be replaced according to the cumulative number of switching times
(switching life).
5.1.7

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 installation screws in both ends of the control circuit terminal block. (These screws cannot be removed.)
Pull down the terminal block from behind the control circuit terminals.
2) Using care 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.
CAUTION
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.
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