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


ITE K-600 Circuit Breaker Question

ITE K-600 Circuit Breaker Question

ITE K-600 Circuit Breaker Question

I have an ITE Power Circuit Breaker K-600 and I am confused on the nameplate Short Circuit Current ratings. One part of the nameplate lists:
600Vac - 22000A
480Vac - 30000A
240Vac - 42000A
But another place on the nameplate states Short Time Current 22000A.

Can someone explain what the Short Time Current rating is? There appears to be a Time component with that rating versus the instantaneous ratings. If so, what amount of time?

Nameplate picture attached.

RE: ITE K-600 Circuit Breaker Question

Per the description below, the time duration for the "short circuit" rating is 3s (ie the Icw rating). I believe that is the same time duration used for ANSI rated CBs as well. Perhaps someone else can comment on that?
Low Voltage Circuit Breakers
Based on IEC 60947-2 (LV switchgear and controlgear - Part 2: Circuit breakers):
In (Rated current)
The rated continuous / uninterrupted current that the circuit breaker can carry.
Icm (Rated short-circuit making current)
The short-circuit current that the circuit breaker can withstand as it is closing where the act of closing initiates the fault.
Icu (Rated ultimate short-circuit current)
The maximum symmetrical short-circuit current the circuit breaker can interrupt.
Ics (Rated service short-circuit current)
The breaking capacity such that the circuit breaker is tested to carry its current continuously. The test sequence verifies that the breaker can be returned to service. Ics is the maximum current the breaker can interrupt multiple times and be returned to service without being damaged and is expressed as a % of Icu.
Icw (Rated short time withstand current)
This is the steady state symmetrical fault current the breaker has to be able to carry for a duration of 0.05s to 3s without exceeding its thermal integrity

"I have not failed. I've just found 10,000 ways that won't work." Thomas Alva Edison (1847-1931)

RE: ITE K-600 Circuit Breaker Question

ANSI 600V would be 0.5 seconds.

RE: ITE K-600 Circuit Breaker Question

Howdy wroggent;
I believe that you are correct; the short time rating for lv circuit-breakers is 30 cycles. The 3s rating is applicable for mv breakers.

"I have not failed. I've just found 10,000 ways that won't work." Thomas Alva Edison (1847-1931)

RE: ITE K-600 Circuit Breaker Question

Agree with wrrogent - the short time rating is a 30 cycle rating.

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!


White Paper: Industrial Control Basics: Contactors
A contactor is an electrical device used for switching an electrical circuit on or off. Considered to be a special type of relay, contactors are used in applications with higher current carrying capacity, while relays are used for lower current applications. Download Now
Research Report: State of IoT Adoption in Product Development 2019
This research report, based on a survey of 234 product development professionals, examines the current state of Internet of Things (IoT) adoption by product design teams, its perceived importance, and what features and capabilities teams consider important when making decision about adding IoT functionality to their products. Download Now
Research Report: Augmented Reality for Maintenance, Repair and Overhaul (MRO)
The term Industry 4.0 denotes a cluster of technologies that’s poised to fundamentally reshape manufacturing and bring about a new industrial revolution. These include 3D printing (AM), the Industrial Internet of Things (IIoT), artificial intelligence (AI) and mixed reality technologies, more commonly known as virtual reality (VR) and augmented reality (AR). Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close