×
Follow Us
Results 1 to 9 of 9

How to Test Breaker through Current Injection Tester ?

 Jump to latest post
    #1
  1. Join Date
    Nov 2016
    Posts
    6
    Reputation

    How to Test Breaker through Current Injection Tester ?

    Can anyone please clarify how to use current injection Tester ? and during the testing how to setup the values of Isd Tsd long time pickup short time pickup

  2. #2
  3. Join Date
    Aug 2015
    Posts
    18
    Reputation
    There are two types of test you can do: primary and secondary injection. Primary injection involves passing high current through the circuit breaker, replicating actual in service current levels at a low voltage. Secondary injection involves passing a very low current (less than 50A max) into the trip unit, bypassing the CT's - this requires a special injection tester.

    Which type of test are you doing? Either way, you want to test your settings as close to their calculated value (determined by a coordination study) as possible. Also, what type of trip unit are you testing? Here are some generic settings you can try if you are unsure about what to set your trip unit at when testing:

    LTPU: 1.0
    LTD: somewhere in the middle (if 24 is max, go 12).
    STPU: 4.0
    STD: 0.200 OUT
    INST: 6.0
    GFPU 0.6
    GFD: 0.200 OUT

    Hope this helps!

  4. #3
  5. Join Date
    Nov 2016
    Posts
    6
    Reputation

    Breaker testing

    I want to learn primary injection testing through current injection tester and I wanna learn basic concept of it for example if I need to test long time pickup what should I have to see first and how can i start the test then long time delay how can I proof that long time delay is fine and working proper through current injection tester and so on like short time pick up ,short time delay instantenious .i will,wait for your reply

  6. #4
  7. Join Date
    Aug 2015
    Posts
    18
    Reputation
    Ok here is a very basic rundown of how to perform each test:

    Long Time Pickup: Usually this test is performed at 1.0X the rating plug, in this example we will say 1000A for simplicity. Start pushing current though the breaker at about 750A and slowly bring current up until the long time pickup indicator comes on, this should be around 1000A. Lower the current until the indicator drops out, and raise the current again until the indicator comes back on. Document this current value.

    Long Time Delay: Set all other pickup values except long time pickup to maximum to prevent unwanted tripping. Delay bands are usually calibrated to 6X the current rating. Using the previous example this would be 6000A. So if your band is 24, it should take about 24 seconds to trip at 6X.

    Short Time Pickup: Set all other pickup values except long time to maximum. Set all delays to maximum except short time, which should be set at 0.100 out. In this example we will test short time at 4X, which should be 4000A. Start with say 3000A and bring up current at a moderate speed until the breaker trips. Document this current value.

    Short Time Delay: Set the short time delay to the desired band. Preset the test current to 1.5X the short time pickup. In the previous example that was 4000A, so test current should now be preset to 6000A. Reset the timer and push current, the breaker should trip within the specified time by the TCC, could be anywhere from 0.080 - 2.000+ seconds.

    Instantaneous: Set to the desired pickup. In this example we will use 8X which would be 8000A. Start pulsing current from about 6000A and slowly increase the current value until the breaker trips. You must reset the timer after each pulse until the circuit breaker trips. Instantaneous trip time is usually 0.080 seconds or less. Document the current value and time when the breaker trips.

    Perform each test on each phase. If you have ground fault you will need to defeat it either with a secondary test kit or by putting two poles in series. The test procedure is similar to the short time test. This is when things get complicated. Hope this helps.

  8. #5
  9. Join Date
    Aug 2015
    Posts
    18
    Reputation
    You might also find this article to be helpful: http://testguy.net/content/197-Chara...d-Coordination

  10. #6
  11. Join Date
    Nov 2016
    Posts
    6
    Reputation
    Thanks a lot Gavin thanks for ur support you great.

  12. #7
  13. Join Date
    Jan 2017
    Location
    Indianapolis, IN
    Posts
    4
    Reputation

    Just another suggestiong

    I would also recommend if your new to breaker testing in general to sit down and study "Time Current Curves" for multiple breaker manufactures, types, etc.

    My first couple years sure I could test a breaker no problem but had issues understanding how to follow a curve (times and multipliers).

    also if you ever go to test Short time delay or ground fault delay with the I2T function in the On position it will be more difficult to get the trip time within the band. It is a little bit more difficult but in my personal opinion if you learn how to run the high current test sets and understand how to read a time current curve you'll do just fine.

    If you ever want time current curves one of the best places to find them is at: http://www.electricalmanuals.net/

    Good luck!

  14. #8
  15. a.lallana@epsii.com is offline Junior Member Pro Subscriber
    Join Date
    Jan 2015
    Posts
    8
    Reputation

    Long time

    Very good the only thing is that NETA recommends long time delay to be tested at 3x instead of 6x.

    Quote Originally Posted by GavinK5 View Post
    Ok here is a very basic rundown of how to perform each test:

    Long Time Pickup: Usually this test is performed at 1.0X the rating plug, in this example we will say 1000A for simplicity. Start pushing current though the breaker at about 750A and slowly bring current up until the long time pickup indicator comes on, this should be around 1000A. Lower the current until the indicator drops out, and raise the current again until the indicator comes back on. Document this current value.

    Long Time Delay: Set all other pickup values except long time pickup to maximum to prevent unwanted tripping. Delay bands are usually calibrated to 6X the current rating. Using the previous example this would be 6000A. So if your band is 24, it should take about 24 seconds to trip at 6X.

    Short Time Pickup: Set all other pickup values except long time to maximum. Set all delays to maximum except short time, which should be set at 0.100 out. In this example we will test short time at 4X, which should be 4000A. Start with say 3000A and bring up current at a moderate speed until the breaker trips. Document this current value.

    Short Time Delay: Set the short time delay to the desired band. Preset the test current to 1.5X the short time pickup. In the previous example that was 4000A, so test current should now be preset to 6000A. Reset the timer and push current, the breaker should trip within the specified time by the TCC, could be anywhere from 0.080 - 2.000+ seconds.

    Instantaneous: Set to the desired pickup. In this example we will use 8X which would be 8000A. Start pulsing current from about 6000A and slowly increase the current value until the breaker trips. You must reset the timer after each pulse until the circuit breaker trips. Instantaneous trip time is usually 0.080 seconds or less. Document the current value and time when the breaker trips.

    Perform each test on each phase. If you have ground fault you will need to defeat it either with a secondary test kit or by putting two poles in series. The test procedure is similar to the short time test. This is when things get complicated. Hope this helps.

  16. #9
  17. ElectricalTestTech's Avatar
    ElectricalTestTech is offline NETA Level IV
    Affiliate Member
    Pro Subscriber
    Join Date
    Sep 2017
    Location
    Washington, DC
    Posts
    69
    Reputation
    Quote Originally Posted by a.lallana@epsii.com View Post
    Very good the only thing is that NETA recommends long time delay to be tested at 3x instead of 6x.
    Yes, we typically test at 3x. Put NETA to the side for a minute. Why do you think NETA recommends a 300% test and not a 600% test. Most long time delays are expressed in a time delay @ 600% current. I know of one manufacturer that uses time bands which are not the same as a time delay @ 600%. This manufacturer is GE. But all the manufacturers test to 600% values. We as test techs want to prove that the curve is accurate so we run 300% tests. And in most cases, 300% current is a much easier magnitude to achieve than 600%.

    Good luck

Subscribe

Share this thread

Related Topics

  1. Contact resistance tester doesn't display any reading
    By lnides in forum Electrical Testing Talk
    Replies: 12
    Last Post: December 21, 2020, 01:32 PM
  2. winding resistance tester and CPC 100
    By moon1958moon in forum Electrical Testing Talk
    Replies: 8
    Last Post: August 4, 2017, 12:09 PM
  3. Continuous current rating of a circuit breaker
    By mainmanmerc in forum NETA Level 2 Exam
    Replies: 4
    Last Post: October 22, 2016, 07:32 PM
  4. Replies: 0
    Last Post: July 7, 2016, 08:35 AM

Tags for this Thread

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