617,657. Protective cut-out systems. DAVIES, A. Oct. 11, 1946, No. 30374. [Class 38 (v)] An arrangement for protecting a three-phase motor against single-phasing, comprises a pair of solenoids c<1>, d<1> connected to the motor terminals a<1>, a<2>, a<3> so as to be across two of the phases, and normally closing contacts c<3>, d3 in series in the no-volt release-coil circuit of the starter switch. Failure of a phase will deenergize one or other solenoid, or insufficiently energize both, so that the spring F opens the no-volt circuit.