Interlock (for safeguarding) : An arrangement that interconnects guard(s) or device(s) with the control system or all or part of the electrical energy distributed to the machine
NFPA 79 Electrical Standard for Industrial Machinery, 2002 ed. http://www.nfpa.org/assets/files/AboutTheCodes/79/ 79-A2002-rop.pdf, (Electr Std for Ind Machinery - Amer) {225 NFC}