NEC Article 404 covers the requirements for switches, including their installation, ratings, and uses. This article ensures that switches are used safely and appropriately in various electrical installations. Here is a comprehensive overview of NEC Article 404:
404.1 Scope
This section establishes the scope of Article 404, which includes general-use switches, snap switches, dimmer switches, and other switch types.
404.2 Definitions
Defines key terms relevant to switches to ensure clarity and consistency within the article.
404.3 Enclosures for Switches
Switch enclosures must provide adequate protection from accidental contact with live parts. This includes ensuring that doors or covers on enclosures do not expose live parts when opened.
404.4 Damp or Wet Locations
Switches installed in damp or wet locations must be enclosed in weatherproof enclosures to prevent moisture ingress, which could lead to electrical hazards.
404.6 Mounting of Switches
Switches must be securely mounted to ensure they remain in place during normal operation. This includes requirements for surface-mounted and flush-mounted switches.
404.8 Accessibility and Grouping
Specifies that switches must be installed at accessible locations and grouped logically for easy identification and operation. Switches must be placed no more than 6 feet 7 inches above the floor unless they are hookstick operable switches or used for specific applications.
404.9 Grounding of Switches
All switches must be grounded to ensure safety. This includes connecting the metal enclosures of switches to the grounding conductor to provide a continuous path for fault currents.
404.10 Knife Switches
Knife switches must be used within their rating and must not be opened under load unless they are specifically rated for interrupting current. This ensures safe operation and prevents arcing and damage.
404.12 Multipole Snap Switches
Multipole snap switches must be used within their ratings and cannot be fed from multiple circuits unless they are listed and marked for such use.
404.14 Rating and Use of Switches
Switches must be used within their rated capacity and for their intended purposes. This section includes requirements for different types of switches such as general-use snap switches, motor-circuit switches, and AC/DC switches.
404.16 Reconditioned Equipment
New provisions address the reconditioning of switches. Only specific types of switches, such as knife switches and those with butt or bolted pressure contacts, are permitted to be reconditioned. This ensures that only safe and reliable reconditioned equipment is used.
For more detailed information and specific requirements, referring to the NEC Handbook and additional resources provided by the NFPA is highly recommended. More insights can be found on resources like Mike Holt Enterprises and The NEC Wiki.