×
Follow Us
Results 1 to 4 of 4

IEEE 1584 circuits less than 240V

 Jump to latest post
    #1
  1. bec51392 is offline NETA Level II Pro Subscriber
    Join Date
    Dec 2019
    Location
    Richmond VA
    Posts
    29
    Reputation

    IEEE 1584 circuits less than 240V

    According to IEEE 1584, Circuits less than 240V supplied from transformers less than 125kVA may be omitted from an Arc Flash Hazard Analysis and will be assumed to have a hazard risk category 0.
    Your Answer: False
    Correct Answer: True

    1584 2002 4.2 states "Equipment below 240 V need not be considered unless it involves at least one 125 kVA or larger low impedance transformer in its immediate power supply."

    BUT 1584 2018 removed that statement and gives direction for 208v and above

  2. #2
  3. TestingProToBe is offline Junior Member Pro Subscriber
    Join Date
    Dec 2017
    Posts
    7
    Reputation

    Can you site the passage?

    Quote Originally Posted by bec51392 View Post
    According to IEEE 1584, Circuits less than 240V supplied from transformers less than 125kVA may be omitted from an Arc Flash Hazard Analysis and will be assumed to have a hazard risk category 0.
    Your Answer: False
    Correct Answer: True

    1584 2002 4.2 states "Equipment below 240 V need not be considered unless it involves at least one 125 kVA or larger low impedance transformer in its immediate power supply."

    BUT 1584 2018 removed that statement and gives direction for 208v and above
    Im a little confused. So they removed the mention on excluding 240 v , 125kva and below. And replaced it by only addressing 208v and above?

  4. #3
  5. bec51392 is offline NETA Level II Pro Subscriber
    Join Date
    Dec 2019
    Location
    Richmond VA
    Posts
    29
    Reputation
    Quote Originally Posted by TestingProToBe View Post
    Im a little confused. So they removed the mention on excluding 240 v , 125kva and below. And replaced it by only addressing 208v and above?
    Sorry I could have worded it better. I submitted it to the report a problem thread and then it was moved here.

    Correct. So the true or false question is no longer accurate since it is no longer true 100% of the time.

    IEEE 1584 2002 section 4.2 end of paragraph 5
    "Equipment below 240 V need not be considered unless it involves at least one 125 kVA or larger lowimpedance
    transformer in its immediate power supply."

    1584 2018 that is completely removed. non existent.
    but 4.2 does state
    "4.2 Range of model
    The following empirically derived model, based upon statistical analysis and curve-fitting programs as well as
    an understanding of electrical arc physics, is applicable for systems with the following parameter range:
    Voltages in the range of 208 V to 15 000 V, three-phase (line-to-line)"

    and 4.3 states

    "Sustainable arcs are possible but less likely in three-phase systems operating at 240 V nominal or less
    with an available short-circuit current less than 2000 A."
    Last edited by bec51392; 2 Weeks Ago at 01:52 PM. Reason: add ref

  6. #4
  7. bec51392 is offline NETA Level II Pro Subscriber
    Join Date
    Dec 2019
    Location
    Richmond VA
    Posts
    29
    Reputation
    Quote Originally Posted by Wiche1971 View Post
    Sustainable arcs are possible but less likely in three-phase systems operating at 240 V nominal or less with an available short-circuit current less than 2000 A.
    right.... but now they still have to be included in the arc flash study? so the true false question on the practice exam is no longer valid?

Subscribe

Login or register to leave a reply!


Share this thread

Related Topics

  1. Field Testing of Motors, IEEE 43
    By SecondGen in forum NETA Level 3 Exam
    Replies: 7
    Last Post: September 5, 2020, 10:20 PM
  2. IEEE Questions
    By MartyCoyne in forum NETA Level 4 Exam
    Replies: 3
    Last Post: May 22, 2018, 01:08 PM
  3. What IEEE level cable terminations should be used?
    By kenner14 in forum NETA Level 4 Exam
    Replies: 1
    Last Post: October 6, 2017, 03:57 PM

Tags for this Thread



Related Content


Follow us


Explore TestGuy


NETA Certification Training


NICET Electrical Power Testing


Help and Support