Pitch system (1) comprising at least one pitch motor drive (3) connected an electrical network (5). Each pitch motor drive (3) is connected to a power bank, and the pitch system comprises a test module adapted to be activated in a test position. The test module comprises a brake module (8) each connected to a pitch motor drive (3), and each brake module (8) is adapted to load a pitch motor drive (3) with a certain load Rb. Hereby a voltage drop takes place over the power bank (6). The power bank (6) is separated into a number of power blocks (9) and the voltage drop ΔV of each power block (9) is adapted to be registered by the test module when the brake