×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

question re circuit breaker damage over continuous tripping

question re circuit breaker damage over continuous tripping

question re circuit breaker damage over continuous tripping

(OP)
I am an audio tech and have been using a 15 amp thermal breaker on a 20 amp load (not my idea.)  Needless to say, the breaker keeps tripping, shutting down one of my amplifiers.

In researching the damage issue to the breaker, I was told that every time it trips, the arcing that takes place leaves more and more damage to the contacts.

Could someone please confirm/deny this and explain what damage is being done.

Thank you.

RE: question re circuit breaker damage over continuous tripping

Yep, very true. Every time it breaks the load, arcing (severity depends on load) occurs. This arcing takes some of the metal off the contacts each time. Whats left is pitted contacts. These pitted contacts add resistance to the contact, increasing heating. As this repeats itself, the problem gets worse and worse, eventually the breaker will fail to make or worse yet, get very hot and fail potentially causing a fire.

RE: question re circuit breaker damage over continuous tripping

Just a comment. If you have breakers that get tripped all the time in test situations, you should consider using a PTTC device like PolySwitch RXE series.  I'm using some 4A 50V versions and at rated current they have a voltage drop of about 0.2V.  Since they are resistive you should not have any trouble paralleling them for higher current.  They can take current bursts of twice the current for about 15 seconds.  They do not totally interupt the power. Once tripped they consume about 3W to keep them hot.  At 12V that is about 1/4 amp, 24V would be 1/8A, etc. Just remove voltage to reset in 10 seconds.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources