Quick Hits

Episode 4: Marking, Terminals & Noninterchangeability (726.124 – 726.130)

SLIDE 1 (HOOK / COVER) ⚡ NEC Quick Hit: Class 4 Marking & Connector Guarding (Part 4) ⚡ 

How do you label Class 4 equipment? How do we prevent someone from plugging a 380V Class 4 line into a standard low-voltage jack? Let's finish Article 726! 👇

SLIDE 2 (TRANSMITTER & RECEIVER MARKING)

Mandatory Labeling Rules:

• Transmitter Markings: Must be durably marked where plainly visible, indicating each Class 4 circuit, along with max voltage and current (e.g., Class 4: +/-190V, 5A).

• Receiver & Socket Markings: Receivers and utilization equipment must display maximum input ratings as well as max output ratings for any terminals or socket outlets.

SLIDE 3 (NONINTERCHANGEABILITY & GUARDING)

Preventing Accidental Cross-Plugging:

• Noninterchangeable Connectors: Connectors for Class 4 circuits must be physically designed so they cannot be interchanged with non-power-limited sources on the premises.

• Guarding Live Parts: Mating connectors and junction points must guard against inadvertent contact with live parts by personnel.

SLIDE 4 (WRAP-UP)

💡 Apprentice Pro-Tip: Noninterchangeable pin configurations and keyed connectors ensure an electrician or technician can never accidentally plug a Class 4 high-voltage line into standard RJ45 or Class 2 terminals!

💬 Save this post for your final code review on Class 4 fault-managed power systems! 🔗 

More code breakdowns and study tools at www.JoshTheSparky.com

← View Chapter 7 Home

← Back To Article 726 Home

← Back To Quick Hits Home