×
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

Switchgear Circuit Breakers

Switchgear Circuit Breakers

Switchgear Circuit Breakers

(OP)
Hi All,

I'm adding four(4) new, 15kV metal-clad switchgear breakers to an existing line-up. I plan to utilize DC power for the tripping, closing, spring-charging and protective relay. Now, my concern is whether the existing battery cells have the adequate capacity (i.e. battery voltage)to provide what I need.

What should I do to ensure or how do I make a check if the battery cells have the some spare capacity for my application.

Appreciate your inputs.   

RE: Switchgear Circuit Breakers

Figure out how much capacity you have from the batteries. (how many amp hours are in the battery)
Figure out how much capacity you currently use or need to have to hold in reserve. (what loads you have currently and how many time you want to be able to operate them and for how long)
Figure out how much capacity you will add. (what load you will add and how long they will need to operate or how many times)
Do the math.

Test the batteries if needed if there is some reason to believe that they are weak.

RE: Switchgear Circuit Breakers

Another thing to bear in mind is the standing load of your protection relay. Your existing breakers may have electromagnetic relays with no standing drain, wheras new relays are likely to be electronic. Depending on the type of circuit breaker there may be an electronic control module with a standing load. If you do have standing loads you would need to check the charger output is sufficient.
Regards
Marmite

RE: Switchgear Circuit Breakers

Battery bank sizing is covered in several IEEE standards, perhaps IEEE 485 (from memory) might be suitable for you.

There is more to it than you might initially consider, although it is not that complicated to work through.

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