Mitsubishi Electric FR-CC2-P, Instruction Manual, Page: 161 / 184

Inspection item
160
PRECAUTIONS FOR MAINTENANCE AND INSPECTION
 Smoothing capacitors
A large-capacity aluminum electrolytic capacitor is used for smoothing in the DC section of the main circuit, and an aluminum
electrolytic capacitor is used for stabilizing the control power in the control circuit. Adverse effects from ripple currents
deteriorate capacitors. Replacement intervals of capacitors vary greatly with surrounding temperatures and operating
conditions. Replace them roughly every 10 years when used in normal air-conditioned environments.
Inspecting the product visually:
• Case: Check that the sides and bottom of the capacitor have not ruptured.
• Rubber seal: Check for any noticeable bulging or severe cracks.
• Check for external cracks, discoloration, leakage, etc. It is assumed that the capacitor has reached the end of its remaining
life when its capacity has dropped below 80% of its rated capacity.
NOTE
• The converter unit diagnoses the control circuit capacitor by itself and can estimate its remaining life. (Refer to page 93 .)
 Relay output terminals
• The contacts of relays deteriorate over time. To prevent faults from occurring, relays must be replaced when they have
reached the maximum number of switching operations (switching life).
• The control terminal block must be replaced in case of failure of the relay connected to the relay output terminals A1, B1,
and C1. (After installing a new control terminal block, set up the control logic for input signals with the jumper connector
(control logic selector). (Refer to
page 45 .))
 Main circuit fuse
A fuse is used inside the converter unit. Replacement intervals of fuses vary with surrounding temperatures and operating
conditions. Replace them roughly every 10 years when used in normal air-conditioned environments.
7.1.7
Converter unit replacement
The converter unit can be replaced with the control circuit wiring kept connected.
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 converter unit's control circuit connector, reinstall the control circuit terminal block, and
fix it with the mounting screws.
NOTE
• Before starting converter unit 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