Lock out, tag out (LOTO) is a safety procedure used to ensure that dangerous equipment is properly shut off and not able to be started up again prior to the completion of maintenance or repair work. It requires that hazardous energy sources be “isolated and rendered inoperative” before work is started on the equipment in question. The isolated power sources are then locked and a tag is placed on the lock identifying the worker and reason the LOTO is placed on it. The worker then holds the key for the lock, ensuring that only he or she can remove the lock and start the equipment. This prevents accidental startup of equipment while it is in a hazardous state or while a worker is in direct contact with it.
The National Electric Code states that a safety/service disconnect must be installed within sight of serviceable equipment. The safety disconnect ensures the equipment can be isolated and there is less chance of someone turning the power back on if they can see the work going on. These safety disconnects usually have multiple places for locks so more than one person can work on equipment safely.
The five safety steps
According to the European standard EN 50110-1, the safety procedure before working on electric equipment comprises the following five steps:
- disconnect completely;
- secure against re-connection;
- verify that the installation is dead;
- carry out earthing and short-circuiting;
- provide protection against adjacent live parts.
Rita braida@chianwelken.com
Post time: Jun-17-2022
