×
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

how to derive tcc for oil cb with dashpot, wh f-124

how to derive tcc for oil cb with dashpot, wh f-124

how to derive tcc for oil cb with dashpot, wh f-124

(OP)
thread238-280767: Relay type

does somebody have tcc for Westinghouse Type F-124-A Oil Circuit-Breaker?

also, in case that there is not one, how can it be derived? both for cb and the dashpot.

is this cb similar to any of the ge ec type ak-15,25,50,75

cb manual
http://www.electricalpartmanuals.com/pdf/circuitBr...

http://www.homewoodsales.com/PDFs/tech-library/AC-...

http://www.homewoodsales.com/PDFs/tech-library/AC-...

RE: how to derive tcc for oil cb with dashpot, wh f-124

Hmm, this is not a low voltage breaker! These come with separate protection relays, (ex.: Westinghouse CO type induction disk) not integrated trip units, electromechanical or electronic.
http://www.electricalpartmanuals.com/pdf/circuitBr...

RE: how to derive tcc for oil cb with dashpot, wh f-124

This is not equivalent to the GE "AK" series, which are low-voltage breakers.

The first manual you attach shows the dashpot installation.

Assuming that the dashpot is still filled with good oil of the proper density (and it has been a long time since I've seen dashpot oil), you can do current injection to determine points on a trip curve. If you have some idea of the full current ratings, then a few tests at 200, 300 and 500% will give you some idea of the time-overcurrent characteristic.

Remember, these were never meant to be precision devices, so abandon the ideas of accuracy you're used to seeing with digital relays, or for that matter, properly maintained induction disk relays.

Further, the contact parting and clearing times are likely to be much different than the 2-3 cycles of modern circuit breakers.

With a lot of care, this equipment can be made serviceable after a fashion.

If I had to think about putting this thing into service, I'd be trying to figure out a way to upgrade.

old field guy

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