This paper provides a statistical analysis of different strategies for no load power transformer's controlled switching. Especially for the reclosing strategy with residual flux, the combined effects of mechanical timing deviation and pre-arc phenomenon have to be taken into account in the algorithm of optimum reclosing instant. Then, with a single phase power transformer model, we compare this strategy with reclosing strategy based on a preceding controlled de-energization using EMTP multiples simulations under a random mechanical time.