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

More Questions about Protective Relays

  1. Aug 5, 2009 #1
    I am trying to protect two power sources from two generators from overcurrent, under/overvoltage, under/overfrequency,etc.
    There will be two generators running during the day and one running at night, I have double throw switches to switch the two breaker panels to run on one generator each or to share one generator. One generator's relay will run almost 24/7 and the other will cycle once per day.(Generators not ran in parallel.)

    I do not wish to use a shunt trip breaker connected to the protective relays for this purpose because I do not have an uninterruptable power supply. I was thinking of using a normally open contactor instead. I know a regular electromechanical relay will not last long in this application. What I am wondering is if it would be best to use a solid state relay or a mercury relay or something else for this application?

    The generators are 83 amp 120/208 volt 3 phase 24 KW.
     
  2. jcsd
  3. Aug 5, 2009 #2
    Since safety is obviously an issue, and there are just so many unanswered questions about your setup, I wouldn't rely on guesses found in a forum. To make a good decision here, you need a pro electrical engineer that has intimate knowledge of your setup and requirements.
     
  4. Aug 5, 2009 #3
    This is a home project I am just looking for something that will last and not get weak if I used electromechanical contactors continues rating and hold contacts the problem would be the risk of the coils becoming weak and failing this is all I am asking about. If the contactor fails, there is no immediate danger. I am an electrician.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: More Questions about Protective Relays
  1. Protective relays (Replies: 0)

Loading...