×
Follow Us
Results 1 to 2 of 2

Confusing question on NETA 2 practice test

    #1
  1. Join Date
    Jan 2017
    Posts
    5
    Reputation

    Confusing question on NETA 2 practice test

    Hey all,

    I was taking the NETA 2 practice test when I encountered a question with what appeared to have two right answers. The question simply said "47" in reference to the IEEE device number, and the four answers were:

    Distance relay
    Directional relay
    Phase balance relay
    Phase sequence relay
    Power factor relay

    The correct answer, according to the IEEE device list I had printed off and sitting right next to me, is both phase balance and phase sequence. This was confirmed by the test itself a few questions later, with the question "Which of the following is the ANSI/IEEE device number for a phase-sequence or phase-balance relay?"

    I got the first question wrong by answering phase sequence (I think) but I got the second question right by answering "47." So my question is, was the first question somehow only one of the two options and I just guessed incorrectly? I'm not sure how that's possible but I wanted to be sure. Here is the device number list I was using as a reference. Is it, and the second question, wrong? http://www.ece.uidaho.edu/ee/power/E...ures/L3/L3.pdf

  2. #2
  3. Join Date
    Apr 2018
    Location
    Michigan
    Posts
    40
    Reputation
    Quote Originally Posted by IncredibleGreg View Post
    Hey all,

    I was taking the NETA 2 practice test when I encountered a question with what appeared to have two right answers. The question simply said "47" in reference to the IEEE device number, and the four answers were:

    Distance relay
    Directional relay
    Phase balance relay
    Phase sequence relay
    Power factor relay

    The correct answer, according to the IEEE device list I had printed off and sitting right next to me, is both phase balance and phase sequence. This was confirmed by the test itself a few questions later, with the question "Which of the following is the ANSI/IEEE device number for a phase-sequence or phase-balance relay?"

    I got the first question wrong by answering phase sequence (I think) but I got the second question right by answering "47." So my question is, was the first question somehow only one of the two options and I just guessed incorrectly? I'm not sure how that's possible but I wanted to be sure. Here is the device number list I was using as a reference. Is it, and the second question, wrong? http://www.ece.uidaho.edu/ee/power/E...ures/L3/L3.pdf

    ANSI 47 - Negative sequence over-voltage protection against phase unbalance resulting from phase inversion, unbalanced supply or distant fault, detected by the measurement of negative sequence voltage. Or, Protection against phase unbalance resulting from phase inversion, unbalanced supply or distant fault, detected by the measurement of negative sequence voltage

    This relay operates on the negative sequence voltage caused by voltage imbalance, reverse rotation, or combinations due to faults. In my experience, phase sequence is more common than phase balance as a descriptor as it measures/operates on negative sequence voltage caused by imbalance.

    I would have answered Phase Sequence Relay.

Subscribe

Share this thread

Related Topics

  1. Which relay is used to protect feeders?
    By EricGoetz92 in forum NETA Level 2 Exam
    Replies: 5
    Last Post: May 8, 2021, 09:14 AM
  2. Decreasing value of interfacial tension
    By EricGoetz92 in forum NETA Level 3 Exam
    Replies: 6
    Last Post: January 29, 2021, 07:16 AM
  3. Practice Test Question: Zone Interlocked Scheme
    By EricGoetz92 in forum NETA Level 3 Exam
    Replies: 10
    Last Post: July 23, 2019, 07:35 PM
  4. Practice Test Question: Negative Sequence
    By EricGoetz92 in forum NETA Level 3 Exam
    Replies: 3
    Last Post: June 14, 2018, 07:36 PM
  5. Practice Test Question: MC Cable Bend Radius
    By EricGoetz92 in forum NETA Level 3 Exam
    Replies: 2
    Last Post: June 13, 2018, 02:58 PM
Follow us


Explore TestGuy


NETA Certification Training


NICET Electrical Power Testing


Help and Support




You are viewing the archives. Enjoy new features and join the conversation at wiki.testguy.net