Dual rated CT

[way2bhushan]

Dear friends
Does anybody knows about dual rated CT's
Is it single core suitable for metering and protection?
Or two core CT (1 metering and 1 protection) is called as dual rated CT

Thanks

 

[randyman]

In the US, a dual-rated CT is one that has a protection class and a metering class, and should be tested to verify both at the factory.
A "two-core" is referred to as a dual-core CT which is two separate cores contained in one housing.

 

[RRaghunath]

Every protection CT is a dual rated CT.
For example, a 5P CT is supposed to meet Class-1 accuracy requirement in the load current range.
The problem arises when the client stipulates Instrument Security Factor (Fs) for metering requirement. Protection class CT will not meet this requirement.

Rompicherla Raghunath