Transformers Current

In order to solve the problem of detect control of axial canal without preliminary surface clearing, the eddy-current transformer with operating butt end... 

FIG. 29-8 Typical high-voltage ac motor starter illiistrating several protective schemes fuses, overload relays, ground-fault relays, and differential relays with the associated current transformer that act as fault-current sensors. In practice, the differential protection current transformers are located at the motor, hut the relays are part of the starter. 

Protective current transformers, for special purpose applications Part-4/1992 BS 7626/1991 ... 

Note For CTs this multiplying factor has been specified as 2.5 for all voltage systems, as in lEC 60044-1. See also Section 15.7 for metering and protection current transformers. 

The current transformers and potential transformers must conform to lEC 60044-1 and lEC 60044-2 respectively. Instrument transformers with the following accuracies must be used. 

All the CT (current transformer) secondaries must be shorted and grounded while conducting the test on the main circuit. This condition is redundant while conducting test on the auxiliary circuit. 

Specificalions for current transformers General requirements Measuring current transformers 2705 Pan 1/1992 Pan 2/1992 BS 7626/1993... 

Common features of a voltage atid a current transformer 15/457... 

General specifications and design considerations for current transformers 15/471... 

For outdoor installations the recommended minimum creep distances for all types of voltage or current transformers are given in Table 15.1, according to lEC 60044-1 or lEC 60044-2. 

Figure 15.15(b) 400 kV bar primary outdoor current transformer (Courtesy BHEL)... 

I2 - Secondary current referred to the primary side Figure 15.17 Equivalent circuit diagram of a current transformer... 

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