This Service Manual is about the Compact 4-Way Air Discharge Cassette Type indoor unit. It describes the construction, wiring diagram, parts rating, refrigerating cycle diagram, control outline, troubleshooting, configuration of control circuit, detachments, and PC board exchange procedures.
This Service Manual provides detailed instructions for the Compact 4‑Way Air Discharge Cassette indoor units (models MMU‑AP0071MH, 0091MH, 0121MH, 0151MH, 0181MH). It includes safety cautions, wiring diagrams, control outlines, troubleshooting procedures, and parts lists needed for installation, maintenance, and repair.
The manual emphasizes proper safety measures such as checking earth wires, using specified parts, and handling the new R410A refrigerant safely. It also lists required tools, pipe material specifications, and step‑by‑step recharge procedures to ensure reliable operation of the air‑conditioning system.
| Ceiling opening dimension | 595 to 660 mm |
|---|---|
| Maximum stand‑up height | 850 mm or less |
| Drain discharge port size | 145.5 mm |
| Refrigerant type | R410A (HFC) |
| Copper pipe oil bond limit | 40 mg/10 m or less |
The units use the new HFC refrigerant R410A; other refrigerants must not be mixed.
Check that the earth wire is correctly connected to the main unit’s earth terminals.