Safeguarding Applications Tongue Interlocks Trojan 5, MSR10RD, Bulletin 100, PLC, Dual Channel 24V DC L1 L2 L3 Reset Guard Closed Momentary Push Button 11 21 12 22 33 34 Trojan Interlock Switch A1 + S13 S23 X1 13 23 33 43 53 63 73 83 91 D13 D21 Minotaur MSR10RD A2 S14 S24 X2 14 24 34 44 54 64 74 84 92 D14 D22 K1 Outputs D13-D14 & D21-D22 Are Delayed Action K2 Contact Protection e.g. Thermal Cut Out M Inputs PLC Outputs K1 Ground K2 Bulletin 100S or 700S Circuit Status Circuit shown with guard door closed, ready for motor starting (via signals from the PLC). Operating Principle The Minotaur MSR10RD immediate action outputs at 13-14 are connected to inputs at the PLC and the delayed outputs at D13-D14 are connected to the contactor K1. The relevant PLC outputs are connected to contactor K2. If the guard is opened the Minotaur contacts 13-14 immediately signal the PLC to stop the motor. The PLC then has a pre-set time limit (adjustable at the MSR10RD) to execute its shut down sequence and switch OFF contactor K2. After this time period has elapsed, the delayed action outputs D13-D14 will switch off contactor K1, thus ensuring isolation even if there is a hardware, program or systematic fault in the PLC. Fault Detection If either contactor K1or K2 sticks ON, the motor will stop on command but the Minotaur cannot be reset (thus the fault is revealed to the operator). A single fault detected on the Minotaur input and output circuits will result in the lock-out of the system to a safe state (OFF). All safety critical single faults will be detected at the next opening of the guard. Comment This system has the high integrity of hard wiring and allows a correctly sequenced shut-down which protects the machine and program. 18-10