×
Follow Us
Results 1 to 4 of 4

Ratio PTs with a 6150?

 Jump to latest post
    #1
  1. bec51392 is offline NETA Level III Pro Subscriber
    Join Date
    Dec 2019
    Location
    Richmond VA
    Posts
    51
    Reputation

    Ratio PTs with a 6150?

    We are doing a large job of nothing but meter and PT checks. 480v board. 480/120 PTs so nothing crazy. Is there a fancy way to run a ratio test in Protection Suite? Or is that just a horrible idea?

  2. #2
  3. Kalbi_Rob's Avatar
    Kalbi_Rob is offline Experienced Member Pro Subscriber
    Join Date
    Feb 2018
    Location
    Jacksonville, NC
    Posts
    290
    Reputation
    Quote Originally Posted by bec51392 View Post
    We are doing a large job of nothing but meter and PT checks. 480v board. 480/120 PTs so nothing crazy. Is there a fancy way to run a ratio test in Protection Suite? Or is that just a horrible idea?
    Can't think of a complete test, but you could run a specified voltage on the primary and read the secondary voltage with a multimeter, and calculate a ratio.
    So, you could put range your voltage and place 3 phase voltage out (all 3 phases at different voltages) and read the secondary to determine all 3 voltages at the same time, or do each phase individually (much easier).

    This is the same thing most TTR perform, as they typically put out 40V and read the return voltage calculating the ratio. If the burden is to high, they will typically drop the voltage to 4V and re-perform the test. Any voltage below 50V is considered de-energized, so I would typically stay below that threshold. Just have to remember your safety protocols and isolate the test sample from the system.
    You can develop an easy excel worksheet to assist with quick calculations. So for 40V should output ~10V and 4V should output ~1V.

  4. #3
  5. bec51392 is offline NETA Level III Pro Subscriber
    Join Date
    Dec 2019
    Location
    Richmond VA
    Posts
    51
    Reputation
    I've done it out of the control panel a few times I just didn't know if there was a back handed way to read it back on the inputs. Maybe even get it to do some math.

    I think you can set the inputs for voltage feedback but its set thresholds, like 15v or something. I've never tried it. I was thinking I could set it to auto run, record the output voltage when it hit 15 feedback then do the math... but at that point I'm probably not making my life any easier than just using a fluke.

  6. #4
  7. SecondGen's Avatar
    SecondGen is offline
    I push buttons.
    NETA Level III Pro Subscriber
    Join Date
    Jan 2014
    Location
    United States
    Posts
    508
    Reputation
    Find a way to isolate the primary and test from there, this way you are testing the entire circuit. If the meter reading is correct, the ratio is good.

Subscribe

Share this thread

Related Topics

  1. What is the turns ratio?
    By franko26 in forum NETA Level 2 Exam
    Replies: 23
    Last Post: February 14, 2022, 10:36 AM
  2. What is the proper formula for 3 phase turns ratio?
    By Js20981 in forum Electrical Testing Talk
    Replies: 2
    Last Post: September 5, 2020, 07:20 PM
  3. Dry Tranformer Turns Ratio
    By shamimkhan in forum Electrical Testing Talk
    Replies: 2
    Last Post: January 18, 2018, 10:22 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