×
Follow Us
Results 1 to 5 of 5

Purpose of Megger Guard Terminal

 Jump to latest post
    #1
  1. Join Date
    Jun 2015
    Posts
    9
    Reputation

    Purpose of Megger Guard Terminal

    What is the purpose of the Guard terminal on a Megohmeter?

  2. #2
  3. SecondGen's Avatar
    SecondGen is offline
    I push buttons.
    NETA Level III Pro Subscriber
    Join Date
    Jan 2014
    Location
    United States
    Posts
    508
    Reputation
    When testing at higher voltages, such as with cable or transformers, the guard terminal can be used to divert surface leakage from the measuring circuit. For example, if you were performing a Primary to Ground test on a transformer you would guard the secondary windings. Not all insulation testers are equipped with a guard terminal.

    Click image for larger version. 

Name:	sample-insulation-test-connections.jpg 
Views:	4955 
Size:	21.8 KB 
ID:	36

  4. #3
  5. Join Date
    Jan 2015
    Posts
    26
    Reputation

    megger guard terminal usage

    If you understood that, which is a excellent explanation, you can transport to the Power Factor testing. The guard, for example, GST - Guard Red, is the same idea, divert from the measurement whatever is connected to the red.

  6. #4
  7. Join Date
    Sep 2019
    Posts
    6
    Reputation

    RE:

    So does the guard allow voltages to pass through or does it immediately go to ground?

  8. #5
  9. Relay1's Avatar
    Relay1 is offline
    I use to be disgusted, now I'm just amused!
    Junior Member
    Join Date
    Nov 2017
    Location
    Central Texas
    Posts
    17
    Reputation

    Guard Mode

    Quote Originally Posted by wightywest View Post
    So does the guard allow voltages to pass through or does it immediately go to ground?
    A simple way to look at it is, you have a closed circuit with the current returning to it's source at the test equipment. Depending on how you hooked up the leads from the set, all or sections of the device current (Leakage) will be measured. The ground lead is just another path back to the test set whether you measure it or not.

Subscribe

Share this thread

Related Topics

  1. Help me understand how a megger works
    By Sanjayo in forum Electrical Testing Talk
    Replies: 1
    Last Post: April 23, 2016, 11:35 AM
  2. Megger MIT Driver Installation Procedure (Windows 7)
    By SecondGen in forum Technical Documents
    Replies: 0
    Last Post: January 29, 2016, 09:53 AM
  3. Megger Offers Free Testing Tactics Webinar Series
    By testguy in forum News and Announcements
    Replies: 0
    Last Post: November 1, 2014, 06:00 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