Genuine Daikin 1322936 Capacitor is the 3 µF, 400 V run capacitor that provides the phase shift for a small single-phase motor in the unit so it starts and runs at speed. When it drifts low or fails the motor it serves struggles to start, runs slow, or stalls and trips. Since a small run capacitor is cheap against the motor it protects, fitting the genuine 3 µF/400 V part is the easy call — held to its rated value where a generic can sit under-spec and leave the motor labouring.