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



Sony Pocket eBook Reader

For the past few years I have reading eBooks on my HTC touch phone. On and off I have debated buying an eReader and recently purchased a Sony PRS-300 ...

Frame Leakage Protection

While not as popular as it once was, frame leakage protection does still have some use in some circumstances.  In essence frame leakage is an earth fault...

EU Code of Conduct on Data Centres - Best Practices

The European Union is implementing a voluntary code of practice for participants with the aim of improving the overall efficiency of data centres. As part...

Understanding Circuit Breaker Markings

IEC 60947 is the circuit breaker standard and covers the marking of breakers in detail. Any manufacturer following this standard should comply with the...

Variable Frequency Drive

Variable frequency drives are widely used to control the speed of ac motors.  This note looks at the mechanisms which enable drive units to control the...

Magicians of Engineering

The other day I was reading 'Night of the New Magicians' by Mary Pope Osborn with my son.  The story is about a young boy and girl who travel back in time...

What happened to the cable notes?

If you are wondering what happened to our cable notes, the short answer is that we have moved them to myCableEngineering.com.  The "Knowledge Base" at...

IEC 61439 Verification Methods

The (relatively new) switchgear and control gear standard, IEC 61439 'Low-voltage switchgear and controlgear assemblies' has three methods which can be...

Laplace Transform

Laplace transforms and their inverse are a mathematical technique which allows us to solve differential equations, by primarily using algebraic methods...

Contribute to myElectrcial

Have an opinion or something to say, want to ask or answer questions, share your knowledge then use our site to do it . As a community of people interested...

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