ECM Buyers' Guide
  

Code Q&A

Oct 7, 2005 10:44 AM, By Mike Holt


















Q.When is a two-pole breaker required for a multiwire branch circuit?

A.Multiwire and multiple branch circuits that supply devices or equipment on the same yoke (also called a strap) must be provided with a means to disconnect simultaneously all ungrounded conductors that supply those devices or equipment [210.4(B) and 210.7(B)]. Individual single-pole circuit breakers with handle ties identified for the purpose — or a breaker with common internal trip — can be used for this application [240.20(B)(1)].

Note: The intent of this rule is to prevent people from working on energized circuits that they thought were disconnected from their source.

Want to use this article? Click here for options!



Acceptable Use Policy
blog comments powered by Disqus

what's wrong here?

What's Wrong Here?

Nov 5, 2009 11:50 AM

What's Wrong Here?

Oct 22, 2009 11:16 PM

What's Wrong Here?

Oct 8, 2009 3:32 PM

View all What's Wrong Here?

product of the week

LED light engine

November 2, 2009

LED light engine

View all 2009 Products of the Week

Recent Comments

More...


EC&M TV

Exterior Fixture Box for Brick or Stone

Installing a fixture box in a brick or stone wall just got easier with Arlington’s new adjustable depth box!

Southwire's 2009 Cable Innovation Road Show

Gain years worth of insight in only 2-1/2 hours with Southwire’s 2009 Cable Innovation Road Show with Grounding Seminar. The agenda is packed with valuable information that focuses on installation tips!

Listen
Sizing Gen-Sets: Facts, Hints, and Good Judgment
Listen

The complexities of today’s commercial or industrial facility, with their equipment environment of linear and nonlinear loads, places a whole new light on sizing engine-generator sets.

Arc Mitigation - A Total System Approach
There’s no question the risk of arc flash hazards is real in the electrical industry. What many don’t always realize is the impact in business interruption from such events typically far outweighs the physical damage to equipment. View this On Demand Webinar!

Implementing an Industrial Ethernet Infrastructure that's Built to Last
This webinar explores the key benefits of implementing a robust complete, end-to-end Industrial Ethernet solution – from cabling and connectivity, to active components and associated hardware. View this On Demand Webinar!

resources

product info icon

product info

tradeshow icon

tradeshow

research icon

research

rss icon

rss

Browse Back Issues

Browse Back Issues