#IAEINewsLive – Article 408 – 6 NEC Cycles of Code Changes

This #IAEINewsLive session will take a look at Article 408 significant changes from the 2002 version of the NEC through the 2020 version of the NEC. Article 408 has changed over the years and this session will walk through some of the significant changes during this wide time frame. It’s really interesting to walk back through history and see where and how the NEC has changed and this session will take a brief look at Article 408 over this time period.

2002 NEC Is the cycle that we moved from Chapter 3 to Chapter 4. Marking requirement changes for arc flash entered the NEC in this year 110.16 Flash Protection. This was a very controversial topic when you look at the ROP and ROC documents that formulated this new requirement.
– 408.4 changes in marking for circuit directory
– 408.14 Panelboard classification (Lighting etc.)
– 408.16(B) Power Panelboard Protection
– 408.21 Grounded Conductor Terminal

2005 NEC
– 408.3(C) Used as Service Equipment
– 408.4 Circuit Directory or Circuit Identification
– 408.5 Clearance for Conductor Entering Bus Enclosures
– 408.7 Unused Openings is new for this cycle
– 408.20 Location of Switchboards
– 408.30 General requirements for Panelboards
– 408.36(B) Power Panelboard Protection
– 408.36(C) Snap Switches Rated at 30 Amperes or Less

2008 NEC saw the removal of the 42 circuit rule and other modifications to accommodate this.
– 408.3(D) Terminals
– 408.3(F) High-Leg Identification
– 408.4 Circuit Directory or Circuit Identification
– 408.36 Overcurrent Protection
– 408.40 Grounding of Panelboards
– 408.54 Maximum Number of Overcurrent Devices
– 408.55 Wire-Bending Space in Panelboards
– 408.58 Panelboard Marking

2011 NEC introduced the limitation of this Article only applying to 600V and below equipment. Also a new source of supply marking for equipment in other than dwelling units.
– 408.1 Scope
– 408.2 Other Articles
– 408.3(F) Switchboard or Panelboard Identification
– 408.4 Field Identification Required
– 408.55 Wire-Bending Space Within an Enclosure Containing a Panelboard

2014 NEC added Switchgear to this article and we see a new definition of switchgear in Article 100.
– 408.1 Scope – Added Switchgear
– 408.2 Other Articles
– 408.3(A) Conductors and Busbars on a Switchboard, Switchgear, or Panelboard
– 408.3(E) Bus Arrangement
– 408.3(F) Switchboard, Switchgear or Panelboard Identification
– II Switchboards and Switchgear

2017 NEC saw modifications to require barriers on service panelboards through adding panelboards to 408.3(A). This began the journey of changing the 6 disconnect rule and additional barrier requirements now found in Article 230.
– 408.3(A)(2) Service Panelboards, Switchboards, and Switchgear

2020 NEC saw changes to now require marking of available fault current on all equipment covered by Article 408. Also we see Reconditioning now in the NEC and guidance added for this equipment covered by Article 408.
– 408.6 Short-Circuit Current Rating, new section
– 408.8 Reconditioning of Equipment
408.23 Power Monitoring and Energy Management Equipment


Thomas A. Domitrovich
Thomas Domitrovich, P.E., LEED AP, is vice president of technical sales at Eaton, as well as an electrical engineer. He is actively involved with various electrical industry organizations, focusing on the continued growth of electrical safety. He sits on NFPA Code Making Panel 2 for the continued development of the National Electrical Code (NFPA 70).