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NFPA 79: Electrical Standard for Industrial Machinery (2024 Edition)

What You Need To Know

Actionable Tip for Supervisors:  Conduct a Disconnect Label Audit this quarter. Have your team verify that all disconnects are clearly labeled “Machine Supply Circuit” per the 2024 NFPA 79 update. This simple action can prevent servicing errors, reduce risk of injury, and help you pass inspections with ease.

Do Your Machines Meet the New 2024 NFPA 79 Electrical Safety Standards?

If your facility operates or builds industrial machinery, the 2024 edition of NFPA 79 introduces critical updates your team must know—especially in areas like labeling, surge protection, SCCR, cybersecurity, and wiring identification.

Disconnect Labeling Requirements

• What Changed: Disconnects must now be clearly labeled “Machine Supply Circuit.”
• Why It Matters: Clear labeling prevents confusion during service or lockout/tagout, a common cause of arc flash and shock incidents.
• Real-World Example: In 2022, OSHA cited multiple facilities for improper or missing disconnect labels, leading to preventable near-miss events.
• Action Step for Supervisors: Audit all disconnects. Confirm labeling is permanent, visible, and compliant with the new NFPA 79 requirement.

Surge Protection Now Required

• What Changed: The 2024 NFPA 79 requires Surge Protective Devices (SPDs) in sensitive and safety-related circuits[us].
• Why It Matters: Voltage spikes from lightning or switching can silently damage PLCs, sensors, and operator interfaces. Even one failure can halt production.
• Real-World Example: A packaging facility reduced control board failures by 70% within a year after adding SPDs to their safety circuits.
• Action Step for Supervisors: Inspect control panels and confirm SPDs are installed in all safety-related and communication circuits.

System-wide SCCR Labeling

• What Changed: Multi-panel machines must now carry a unified Short-Circuit Current Rating (SCCR) for the entire system.
• Why It Matters: Without a unified SCCR, parts of a system may be under-specified, creating hidden hazards during fault conditions.
• Real-World Example: An automotive supplier failed an inspection when separate panel SCCRs didn’t meet system requirements. Once corrected, downtime from electrical faults dropped significantly.
• Action Step for Supervisors: Verify that all multi-panel machines display a unified SCCR label reflecting the lowest-rated component.

Cybersecurity Guidance

• What Changed: NFPA 79 now includes guidance on securing networked controls, firewalls, and access permissions.
• Why It Matters: As facilities adopt Industry 4.0, unprotected control systems are vulnerable to cyberattacks that can disrupt safety-critical processes.
• Real-World Example: In 2021, a ransomware attack on a U.S. food processing plant halted operations for days due to compromised control networks.
• Action Step for Supervisors: Review firewall, authentication, and user permissions on all machine control networks.

Wiring Color Code Changes

• What Changed: DC wires that remain energized must now be orange with blue stripes.
• Why It Matters: This helps technicians quickly identify live circuits, even after the main disconnect is opened, reducing accidental contact risks.
• Real-World Example: A maintenance team avoided a near miss when color-coded wires prevented accidental contact with a live DC circuit.
• Action Step for Supervisors: Update wiring diagrams and retrain technicians on the new color coding scheme.

Practical Business Outcomes

When your team applies these updates, you can expect:

• ✅ Improved Safety & Fewer Incidents
• ✅ Reduced Downtime
• ✅ Inspection Readiness
• ✅ Increased Equipment Lifespan

Who Should Pay Attention?

• Maintenance Electricians & Plant Engineers
• Controls & Automation Technicians
• Safety Coordinators & Electrical Inspectors
• Machine Builders & Integrators

Final Thought for Training Managers

You don’t have to wait for an inspection failure to take action. These NFPA 79 (2024) updates empower your technicians to protect people, equipment, and your bottom line.

For deeper training on applying these requirements, NTT Training’s NFPA 79 (2024) 2-day course covers grounding, bonding, SCCR calculations, surge protection, cybersecurity, and more with hands-on exercises.

Contact NTT Training at 1-800-922-2820 or visit www.nttinc.com to get your team trained.