Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Checking current

  1. Sep 17, 2007 #1
    can anyone explain to a rookie in very simple terms why you can measure voltage from a capacitor (or any other electrical device) that is energized and find no current via phase to ground but measured voltage phase to phase. In my job we're taught to measure phase to phase and phase to ground b4 proceeding to work on any electrical devices.
  2. jcsd
  3. Sep 20, 2007 #2
    What is your ground, when you consider a sole charged capacitor?
  4. Sep 20, 2007 #3
    This is very simple indeed! When you measure the voltage on a capacitor with a digital meter to ground (who uses Simpson 260s anymore) there is no path for current flow to ground.

    That is very smart advice you get at work. I always put my meter on resistance first and check for continuity in the meter leads before proceeding with the measurement. I then check phase to phase and then phase to ground to ensure there is no voltage potential. Sometimes I also check my meter on a known live circuit also to make sure it is working properly. After all of that I touch the electrical part very fast to ensure I don't get a shock. This is from someone who does not need to be reminded anymore.
  5. Sep 20, 2007 #4


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    But don't forget to switch from "resistance" to "voltage" in between :rofl:
  6. Sep 20, 2007 #5
    100% right! My biggest problem is after checking current with my Fluke multimeter, I put the voltage measuring leads in the same holes and then blow the meter fuse, a cycle that keeps repeating.
    Last edited: Sep 20, 2007
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?

Similar Discussions: Checking current
  1. Quick unit check (Replies: 1)