Quick Hits

Episode 4: High-Voltage Grounding & Oil-Filled Reactors (470.21 – 470.22)

SLIDE 1 (HOOK / COVER)

⚡ NEC Quick Hit: Grounding & Oil-Filled Reactors (Part 4) ⚡

Enclosure grounding rules, non-grounded structure exceptions, and compliance with Article 450 transformer vaults—let's finish Article 470! 👇

SLIDE 2 (GROUNDING ENCLOSURES & CASES)

Bonding to Earth (470.21):

• Equipment Grounding Conductor: Resistor and reactor cases or enclosures must be connected to the equipment grounding conductor.

• Isolated Structure Exception: Cases or enclosures supported on a structure specifically designed to operate at other than ground potential are exempt from connecting to the EGC.

SLIDE 3 (OIL-FILLED REACTORS)

Managing Oil-Filled Units (470.22):

• Transformer Vault Rules: The installation of oil-filled reactors must comply with all applicable requirements of Article 450 Part II and Part III (including oil containment and vault construction).

SLIDE 4 (WRAP-UP)

💡 Apprentice Pro-Tip: Always bond your reactor and resistor metal enclosures to the equipment grounding conductor unless they are mounted on elevated structures engineered for ungrounded operation!

💬 Save this post for your final code review on Resistors and Reactors!

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

← View Chapter 4 Home

← Article 470 Resistors and Reactors

← Back To Quick Hits Home