Electrical LOTO Vs. Machine Specific LOTO
Detailed PPE labeling is vital to successfully de-energizing systems per NFPA 70, and in turn, an employer’s long term success. In my previous blog post, I explained the steps necessary to get equipment to a de-energized state safely, and mentioned how safety programs can be tailored to better support your qualified employees.
One of the first safety programs I’d like to identify includes PPE labeling and equipment Lock Out Tag Out (LOTO) goals. While this seems like a very simple concept, many manufacturing facilities lose sight of label continuity over time. In fact, sometimes the very contractors hired to install new equipment in facilities don’t include labeling to properly support LOTO goals.
Article 408.4 in the National Electrical Code (NEC) now requires equipment to be labeled per location, source, or power, a positive first step for new installation in manufacturing. Unfortunately most LOTO programs in place today are “operator or machine specific,” ignoring the “qualified or maintenance staff” NFPA 70E needs.
LOTO programs should not only identify the machine-specific point of disconnect, but also the upstream source of supply. This information must be clearly visible so any qualified employee can recognize where to begin the proper LOTO procedure. In the South Side View image below, the upstream source identifies the feeds Control Panel 1 (CP-1), therefore if an employee has to enter it and obtain a de-energized condition, they can perform LOTO procedures correctly.
In these photos, the E-1 reference (North Wall) could satisfy both the mechanical LOTO needs for the boiler, as well as the upstream LOTO reference for the CP-1 (South Side View). Again, if a maintenance employee only needs to perform a mechanical repair on the boiler, then locking out the CP-1 (South Side View) would be sufficient; but from an electrical safe work practice view, if the employee needs to enter CP-1 (South Side View), then they must lock out the E-1 reference (North Wall).
If your facility has lost sight of its proper LOTO goals, I encourage you to revisit Article 408.4. It is important to consider both your mechanical and electrical LOTO goals for a complete program approach to safety.