When polishing with a car polishing machine, it is important to use high-quality polish. If you use a cheap polish, there is a risk that it will heat up quickly and can no longer be processed properly.
You should also make sure that the polish is not coarse-grained, as this could chip off the protective and coloured paint down to the undercoat within seconds  It is therefore better to use milder products that also contain a protective wax. This saves you having to wax after polishing.
Note, however, that you should always wash the car thoroughly before polishing.