×
Follow Us
Results 1 to 4 of 4

What is defined as "Power Switching?"

 Jump to latest post
    #1
  1. SecondGen's Avatar
    SecondGen is offline
    I push buttons.
    NETA Level III Pro Subscriber
    Join Date
    Jan 2014
    Location
    United States
    Posts
    431
    Reputation

    What is defined as "Power Switching?"

    Does racking out circuit breakers fall under the definition of "power switching?" My company has been on multiple jobs for various customers who are responsible for power switching, yet they expect us to rack out breakers connected to hot bus for testing.

    It has always been my understanding that the process of power switching included racking out any associated circuit breakers for lockout/tagout or testing. Does anyone here have a different definition?

    Seems like most customers take it literally to mean throwing a switch or operating a circuit breaker and that's it. Is there anything written in a standard that defines "power switching?"

    NETA defines ready-to-test condition as equipment being in an isolated state. Maybe we should update our customer requirements to include this definition rather than the generic term "power switching."

    I need to review 70B and E to see what they say. What do you guys typically do in these situations?

  2. #2
  3. Kalbi_Rob's Avatar
    Kalbi_Rob is offline Experienced Member
    Join Date
    Feb 2018
    Location
    Richmond, VA
    Posts
    201
    Reputation
    Quote Originally Posted by SecondGen View Post
    Does racking out circuit breakers fall under the definition of "power switching?" My company has been on multiple jobs for various customers who are responsible for power switching, yet they expect us to rack out breakers connected to hot bus for testing.

    It has always been my understanding that the process of power switching included racking out any associated circuit breakers for lockout/tagout or testing. Does anyone here have a different definition?

    Seems like most customers take it literally to mean throwing a switch or operating a circuit breaker and that's it. Is there anything written in a standard that defines "power switching?"

    NETA defines ready-to-test condition as equipment being in an isolated state. Maybe we should update our customer requirements to include this definition rather than the generic term "power switching."

    I need to review 70B and E to see what they say. What do you guys typically do in these situations?
    From NFPA 70E:
    Disconnecting (or Isolating) Switch (Disconnector, Isolator): A mechanical switching device used for isolating a circuit or equipment from a source of power.

    Our company has taken that definition to mean any equipment that has power applied to it, must be de-energized completely prior to performing work, otherwise a switching authorization is needed to be signed by all parties. That definition includes racking out of breakers since power is still applied to the breaker EQUIPMENT. Either the power source upstream must be de-energized, or breaker racked out to fully withdrawn position with appropriate arc-flash mitigation methods.

  4. #3
  5. Join Date
    Sep 2017
    Location
    California
    Posts
    19
    Reputation

    Power Switching

    I am unsure of the concrete definition, but my company will not perform testing / service on any breaker unless it is racked out. End user is always responsible for placing the equipment in a safe location for testing for us.

    However, many NETA companies I have worked with will rack the breaker in or out after power has been proven to be removed by the onsite staff / utility provider. We are not a NETA company, we are a breaker repair / testing company.

  6. #4
  7. Join Date
    Jul 2020
    Posts
    3
    Reputation
    It sounds like your quote/contract is too vague. They are opening the feeders for you, which is at least SOMETHING but obviously not ideal.

    The quote should be worded such that the line and load side of the breaker are in the de-energized condition if that's what you desire.

    We work closely with our customers and review the one-line to verify the condition we expect and if the mains/load breaks need to come down so we can work on the breakers but we won't rack out on hot bus. If possible, we can swap tested/untested breakers around to keep downtime low on critical loads. If these criteria can't be satisfied, then that sub simply won't be tested.

    However, we typically do all of the switching and ground placements for our customers, putting the LOTO and energy control in our possession.

Subscribe

Login or register to leave a reply!


Share this thread

Related Topics

  1. Gen Breakers Failed to close just "Click"
    By Warrengarber in forum Electrical Testing Talk
    Replies: 1
    Last Post: 3 Weeks Ago, 10:29 AM
  2. Switching under full load.
    By TrapFlyVenus in forum Safety and Arc Flash Talk
    Replies: 2
    Last Post: April 20, 2020, 02:16 PM
  3. Replies: 7
    Last Post: August 3, 2017, 03:38 PM
  4. Megger Insulation Tester "br.d" Error Code
    By iwanttotest in forum Electrical Testing Talk
    Replies: 1
    Last Post: February 2, 2017, 02:29 PM

Tags for this Thread



Related Content


Follow us


Explore TestGuy


NETA Certification Training


NICET Electrical Power Testing


Help and Support