Results 1 to 4 of 4
  1. #1
    Join Date
    Mar 2007
    Location
    Austin, TX
    Posts
    375

    Default SE panel - breakers

    Does anyone know of a scenario when handle ties at these remote panel and a/c breakers would not be required?

    Thanks

    Similar Threads:
    ***IMPORTANT*** You Need To Register To View Images ***IMPORTANT*** You Need To Register To View Images

  2. #2
    Join Date
    Mar 2007
    Location
    Hudson, WI
    Posts
    645

    Default Re: SE panel - breakers

    Quote Originally Posted by Eric Shuman View Post
    Does anyone know of a scenario when handle ties at these remote panel and a/c breakers would not be required?

    Thanks
    Nope


  3. #3
    Mike Dicken's Avatar
    Mike Dicken Guest

    Default Re: SE panel - breakers

    Quote Originally Posted by Eric Shuman View Post
    Does anyone know of a scenario when handle ties at these remote panel and a/c breakers would not be required?

    Thanks
    The 2005 NEC addresses this subject in Articles 210.4 and 210.7. The bottom line is this - To ensure that the power to a device is completely "OFF", each ungrounded conductor to that device must be protected by an over current protection device (OCPD) which has an approved tie. As such, tripping the breaker will simultaneously open the circuit to every ungrounded conductor supplying that device.

    Connecting each ungrounded conductor supplying power to a device by using a seperate breaker for each ungrounded conductor WILL allow the device to work, but the practice is UNSAFE. The purpose of the NEC is to ensure that electrical systems are installed in a manner that protects people and property by minimizing the risks associated with the use of electricity (see Article 90.1).


  4. #4
    Join Date
    Mar 2007
    Location
    Ormond Beach, Florida
    Posts
    25,308

    Default Re: SE panel - breakers

    Quote Originally Posted by Mike Dicken View Post
    The 2005 NEC addresses this subject in Articles 210.4 and 210.7.
    Unfortunately, those two references do not apply to 240 volt circuits, which are shown; 210.4 covers multi-wire branch circuits and 210.7 covers Branch circuit receptacle requirements.

    From the 2005 NEC. (underlining is mine)
    240.20 Ungrounded Conductors.
    - (B) Circuit Breaker as Overcurrent Device. Circuit breakers shall open all ungrounded conductors of the circuit unless otherwise permitted in 240.20(B)(1), (B)(2), and (B)(3). (Jerry's note: None of the exceptions apply to what is shown.)
    - - (1) Multiwire Branch Circuit. Except where limited by 210.4(B), individual single-pole circuit breakers, with or without approved handle ties, shall be permitted as the protection for each ungrounded conductor of multiwire branch circuits that serve only single-phase line-to-neutral loads.
    - - (2) Grounded Single-Phase and 3-wire dc Circuits. In grounded systems, individual single-pole circuit breakers with approved handle ties shall be permitted as the protection for each ungrounded conductor for line-to-line connected loads for single-phase circuits or 3-wire, direct-current circuits.
    - - (3) 3-Phase and 2-Phase Systems. For line-to-line loads in 4-wire, 3-phase systems or 5-wire, 2-phase systems having a grounded neutral and no conductor operating at a voltage greater than permitted in 210.6, individual single-pole circuit breakers with approved handle ties shall be permitted as the protection for each ungrounded conductor.

    The end result, though, is the same as what Mike posted, "The bottom line is this - To ensure that the power to a device is completely "OFF", ... ", i.e., each ungrounded conductor has power removed by either common trip breakers or handle ties between separate breakers.

    By the way - don't forget that the white conductor should not be "white", it is required to be "permanently reidentified by painting" (not tape) to a color other than white, green, or gray, i.e., black, red, brown, etc.

    Jerry Peck, Construction / Litigation Consultant
    Construction Litigation Consultants, LLC ( www.ConstructionLitigationConsultants.com )
    www.AskCodeMan.com

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •