A protection switch includes a plurality of single-pole protection switch modules in a mechanically coherent unit forming a multi-pole protection switch configuration. Each module includes a housing, a switching arm, a moving contact on the switching arm pivotably movable against a fixed contact between closed and open positions, a manual operating mechanism for adjusting the switching arm between the closed and open positions and a tripping mechanism for automatically resetting the switching arm into the open position upon a tripping condition. The manual operating mechanisms of all modules are coupled so that the modules are only switched jointly. The tripping mechanisms of all modules are coupled so that the tripping mechanism of each also trips all others. A one-piece coupling is insertable between adjoining modules for both mechanically fixing the modules to one another and coupling the manual operating mechanisms and the tripping mechanisms of the adjoining protection switch modules.