For A/C Self-generating coaches, the system is like this. Two 25KW alternators are connected to the axles to generate power. This output is rectified to 110V DC and charges the coach batteries. This DC is again fed to two 25KVA inverters that supply 415V 3 phase current to the roof mounted A/C units. Earlier, when IR used under-slung A/C units, they used DC compressors. The roof mounted AC units that are commonly used in ICF coaches now are induction motors.