METROSIL 600A/ S7/ P/ 6331, 600A/ S3/ I, 600A/ S1/ 1008

METROSILS FOR HIGH IMPEDANCE RELAYS In some applications of high impedance relays a non-linear Metrosil resistor is required to limit the current transformer secondary voltage to a safe level during maximum internal fault condition. 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. For larger fault currents refer to Metrosils for relays on 5A CTs. Table 1 Identification of Metrosils for Relays on 1A CTs. Single element or three element Metrosils are provided for use with single and triple pole relays respectively. Maximum Relay Setting Voltage NomCin al Characteï ¿ ½ r istic Single Pole Relay Triple Pole Relay 125V rms 175V rms 185V rms 450 0.25 600-A/ S1/ 256 600-A/ S3/ I/ 802 300V rms 325V rms 900 0.25 600-A/ S1/ 1088 600-A/ S3/ I/ 1195 400V rms 1100 0.25 600-A/ S1/ 6315 600-A/ S3/ I/ 6324 V = CI ï ¿ ½ For dc or instantaneous values. ï ¿ ½ C Irms Vrms 1 2 52 . 0 ï ¿ ½ ï ¿ ½ ï ¿ ½ ï ¿ ½ ï ¿ ½ ï ¿ ½ ï ¿ ½ = For applied sinusoidal voltages. Vpeak = 1.09C( Irms) ï ¿ ½ For applied sinusoidal currents. Table 2 Leakage current, protection voltage and short time currents. Short Time Current Rating Metrosil Identification Maximum Relay Setting Voltage Maximum Metrosi l Leakage Current at max. Relay Setting Voltage Maximum Protection Voltage at the peak of 50A rms 1 sec. 2 sec. 3 sec. Maximum Continuous Voltage Rating 125V rms 19 mA rms 1435V pk 600-A/ S1/ 256 175V rms 73 mA rms 1435V pk 185V rms 90 mA rms 1435V pk 45A rms 30A rms 22A rms 200V rms 300V rms 30 mA rms 2870V pk 600-A/ S1/ 1088 325V rms 50 mA rms 2870V pk 39A rms 30A rms 17A rms 350V rms 600-A/ S1/ 6315 400V rms 55 mA rms 3500V pk * 46A rms 26A rms 19A rms 425V rms * 600A-A/ S1/ 6315 will hold to 3400V pk at peak of 46A rms and 3000V pk at peak of 30A rms. 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. Table 3 Identification of Metrosils for Relays on 5 A CTs. Max. Internal Max. Relay Setting Voltage Secondary Fault Current 200V rms 250V rms 275V rms 300V rms 50A rms 600A/ S1/ 1213 C = 540/ 640 600A/ S1/ 1214 C = 670/ 800 600A/ S1/ 1214 C = 670/ 800 600A/ S1/ 1223 C = 740/ 800 100A rms 600A/ S2/ P/ 1217 C = 470/ 540 600A/ S2/ P/ 1215 C = 570/ 670 600A/ S2/ P/ 1215 C = 570/ 670 600A/ S2/ P/ 1196 C = 620/ 740 150A rms 600A/ S3/ P/ 1219 C = 430/ 500 600A/ S3/ P/ 1220 C = 520/ 620 600A/ S3/ P/ 1221 C = 570/ 670 600A/ S3/ P/ 1222 C = 620/ 740 Table 4. Leakage current, protection voltage and short time currents. Metrosil Short Time Current Rating Identification Maximum Relay Setting Voltage Maximum Metrosil Leakage Current at max. Relay Setting Voltage Maximum Protection Voltage at the peak of Fault Current 1 sec. 2 sec. 3 sec. Maximum Continuous Voltage Rating 600-A/ S1/ 1213 200V rms 35 mA rms 1730V pk 50A rms 30A rms 20A rms 220V rms 250V rms 40 mA rms 600A/ S1/ 1214 275V rms 50 mA rms 2120V pk 50A rms 25A rms 18A rms 290V rms 600-A/ S1/ 1223 300V rms 50mA rms 2400V pk 40A rms 20A rms 15A rms 330V rms 600-A/ S2/ P/ 1217 200V rms 70mA rms 1730V pk 100A rms 60A rms 45A rms 230V rms 250V rms 75mA rms 600-A/ S2/ P/ 1215 275V rms 100mA rms 2120V pk 90A rms 50A rms 35A rms 290V rms 600-A/ S2/ P/ 1196 300V rms 100mA rms 2400V pk 80A rms 45A rms 30A rms 330V rms 600-A/ S3/ P1219 200V rms 100mA rms 1730V pk 150A rms 85A rms 60A rms 220V rms 600-A/ S3/ P/ 1220 250V rms 100mA rms 2120V pk 135A rms 75A rms 55A rms 265V rms 600-A/ S3/ P/ 1221 275V rms 100mA rms 2200V pk 125A rms 70A rms 50A rms 290V rms 600-A/ S3/ P/ 1222 300V rms 100mA rms 2600V pk 115A rms 65A rms 40A rms 330V rms