Asked by Farid Habibi on Apr 26, 2024
Verified
When replacing modules or working on equipment controlled by the PLC installation, the safest way to proceed is to: 
A) de-energize the MCR coil.
B) block open the emergency stop switch.
C) remove the fuse from the circuit.
D) pull and lock the disconnect switch.
De-energize MCR Coil
The process of removing electrical power from a Master Control Relay (MCR) coil, which stops the current path in the control circuit.
Disconnect Switch
A disconnect switch, also known as an isolator switch, is a device used to ensure that an electrical circuit is completely de-energized for service or maintenance.
- Acknowledge the essential nature of emergency stop circuits and the commitment to safety practices in both PLC programming and hardware management.
Verified Answer
MY
Manuel Yanez IIIApr 27, 2024
Final Answer :
D
Explanation :
Pulling and locking the disconnect switch is the safest way to ensure that the equipment is completely de-energized and cannot be accidentally turned on while maintenance is being performed. This helps to protect both the technician and the equipment.
Learning Objectives
- Acknowledge the essential nature of emergency stop circuits and the commitment to safety practices in both PLC programming and hardware management.