Quick Hits

Episode 4: High-Voltage Neon Secondary Wiring & GTO Cables (600.32)

SLIDE 1 (HOOK / COVER) ⚡ NEC Quick Hit: High-Voltage Neon Secondary Wiring (Part 4) ⚡ 

Over 1000 volts firing up neon tubing? Part II of Article 600 enforces rigid raceway, spacing, and cable requirements for high-voltage neon secondaries. Let's finish Article 600! 👇

SLIDE 2 (GTO CABLE & RACEWAY RULES)

High-Voltage Secondary Construction:

• Type GTO Cable: Conductors must be listed as gas tube sign and ignition cable (Type GTO), rated for 5, 10, or 15 kV, minimum 18 AWG, and rated for 105°C (221°F).

• Raceway Limits: Conduit or tubing enclosing over 1000V neon secondaries must contain only one conductor and be a minimum trade size of 1/2 (metric designator 16).

SLIDE 3 (SPACING & LENGTH RESTRICTIONS)

Keeping Clearance & Distance:

• Ground Spacing: Nonmetallic conduit enclosing GTO cable must be spaced at least 38 mm (1½ in.) from grounded metal parts (or 45 mm for >100 Hz).

• Conductor Length: Secondary runs from transformers to the first tube electrode are capped at 20 ft in metal conduit or 50 ft in nonmetallic conduit.

SLIDE 4 (WRAP-UP)

💡 Apprentice Pro-Tip: 

Under Section 600.32(I), equipment having an open-circuit voltage exceeding 1000 volts shall not be installed in or on dwelling occupancies! Keep high-voltage neon strictly commercial.

💬 Save this post for your final code review on electric signs and neon lighting! 🔗 

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

← View Chapter 6 Home

← Back To Article 600 Home

← Back To Quick Hits Home