Relay protection

Metrosil provides effective protection against high voltage surges in high impedance relay schemes.

 

Correct Metrosil selection ensures that the best protection is obtained while maintaining a Metrosil leakage current low enough to have negligible effect on the accuracy of the relay at its maximum setting voltage. The Metrosil chosen depends on the relay setting voltage and the maximum secondary internal fault current.

Relays attached to Current Transformers with 1A rated Secondary Output.

Single disc Metrosils are suitable for secondary internal fault currents up to 50A rms. Metrosils with multiple discs connected in parallel are used for larger fault currents.

Relays attached to Current Transformers with 5A rated Secondary Output.

The Metrosil chosen depends on the relay setting voltage and the maximum secondary internal fault current. Single disc Metrosils are suitable for secondary internal fault currents up to 50A rms. Metrosils with multiple discs connected in parallel are used for larger fault currents.

 

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