Mitsumi electronic FR-F520-0.75K, 55K Inverter replacement, Smoothing capacitors, Relays

PROTECTIVE FUNCTIONS

(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 an ordinary, air-conditioned environment, change the capacitors about every 10 years.

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).

5.3.8 Inverter replacement

The inverter can be changed with the control circuit wiring kept connected. Before replacement, remove the screws in the wiring cover of the inverter.

1)Remove the mounting screws in both ends of the control circuit terminal block.

2)With both hands, pull down the terminal block from the back of the control circuit terminals.

3)When installing the terminal block to a new inverter, exercise care not to bend the pins of the control circuit terminal block connector.

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