Difference Between Live and Dead Tank Circuit Breakers 

By on


Siemens Dead Tank Circuit Breaker
A quick post in connection with an email question:

Live Tank -  the circuit breaker the switching unit is located in an insulator bushing which is live at line voltage (or some voltage above ground). Live Tank circuit breakers are cheaper than dead tank and require less space.

Dead Tank -  the switching unit is located within a metallic container which is kept a earth potential.  As the incoming/outgoing conductors are taken through insulated bushings, it is possible to place current transformers on these (with a Live Tank arrangement this is not possible and separate CTs are required). 

The terms Live and Dead Tank normally only apply to high voltage circuit breakers



Steven McFadyen's avatar Steven McFadyen

Steven has over twenty five years experience working on some of the largest construction projects. He has a deep technical understanding of electrical engineering and is keen to share this knowledge. About the author

myElectrical Engineering

comments powered by Disqus

  1. tang's avatar tang says:
    8/23/2012 8:15 AM

    What is the ground clearance for dead tank CT?

    • Steven's avatar Steven says:
      8/26/2012 12:17 PM

      With a dead tank circuit breaker, the CT primary side is still isolated, so I'm not sure about why you are worried with ground clearance.


Comments are closed for this post:
  • have a question or need help, please use our Questions Section
  • spotted an error or have additional info that you think should be in this post, feel free to Contact Us



Cable Sizing Software

When sizing cables nearly, everyone uses some form of software. This ranges from homespun spreadsheets to complex network analyses software. Each has its...

What is an Open Delta Transformer

In three phase systems, the use of transformers with three windings (or legs) per side is common.  These three windings are often connected in delta or...

New Mail Chimp

We've been sending out Newsletters on a regular basis for a few weeks now. To do this we have been using Google's Feedburner service. While Feedburner...

Battery Cars A to Z

Battery powered cars are a hot topic and widely debated. The pros, cons, issues and time frames can be talked about endlessly. An article by the Telegraph...

A mechanical engineering paper, some history and memories

I was digging in my bookshelf and came across the 80th Anniversary Association of Mine Resident Engineers, Papers and Discussions Commemorative Edition...

Are We Losing Professional Integrity

I have been thinking recently that there appears to be less professional integrity around than when I first started my career in electrical engineering...

Voltage Levels to IEC 60038

The standard aims to consolidate AC and traction voltages within the industry and defines the following bands: band 1 - A.C. systems 100 V to 1...

Electric Motors

Collection of links to various places with useful motor information. I’ll try and return to the page every now and again to update it with any motor notes...

Post Editing Tips

If you at all familiar with programs like office and outlook, then adding and editing posts is pretty straightforward and intuitive.  However, there are...

Smarter Electrical Distribution

The other day I came across an article in Technology Review on the development of a smart transformer. A professor at North Carolina State University is...

Have some knowledge to share

If you have some expert knowledge or experience, why not consider sharing this with our community.  

By writing an electrical note, you will be educating our users and at the same time promoting your expertise within the engineering community.

To get started and understand our policy, you can read our How to Write an Electrical Note