What is the difference between dead tank type and live tank type current transformer?

The enclosure that houses winding in other words the tank is at line potential while in the other case it is at earth potential. it is the same in case of circuit breakers too.
From NK Sharath Kumar
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res fax 080 22290151,l/l 080 22233669,sharathkumar@vsnl.net

With live tank circuit breakers, the enclosure that houses the contacts is energized, ie. "live". Dead tank circuit breaker's contact enclosures are not energized and are connected to the ground grid. Live tank breakers are usually less expensive but you have to have separate current transformers.