The Cryogenic pumping section (CPS) has been installed at the Tritium Laboratory Karlsruhe for the neutrino mass experiment KATRIN. The 7-m long cryostat is part of the tritium pumping and transport section of the KATRIN experiment. The cryostat hosts seven superconducting solenoid magnet modules in series with a maximum magnetic field of 5.6 T. The magnet safety system (MSS) is the central part for the safe operation of the CPS. A distinct quench detection is of interest but not trivial because of the nonnegligible inductive coupling between neighbouring magnet modules. A distinct quench detection method has been developed based on the combination of a global detector and two (or more) detectors based on the conventional bridge method and a programmable logic controller. TheMSS together with the quench detection system and an external dumping unit has been successfully commissioned with the CPS magnet. This paper presents the first commissioning results.