The application of small and medium capacity generator breaker in domestic hydropower stations is in the beginning period, and the experience of their design, selection and reformation is very little. The characteristics of generator beaker was introduced in brief, and the factors must be considered in breafer type selection were put forward. There are some defects in current vacuum breaker, so the breaker must be reformed in practical operation. The reformation process and debug method of the generator breaker were described for reference of the same trade or occupation.
