WSRD Interlocked Receptacles are designed to prevent electrical arcing when fixed or portable heavy duty equipment is used in adverse environments. Available in 30, 60 and 100 A designs, these metallic receptacles feature either a fused or non-fused disconnect and mechanical interlock that prevents plug removal under load. With a plug engaged and the switch in the ON position, the plug can't be removed. With the switch turned OFF and the plug removed, the receptacle can't be energized.