GE P24DM - Use of ANSI C-Class Cts

Secondary Internal Fault Current Recommended Metrosil types for various voltage settings
50A
600A/S1/S1213
C = 540/640
35 mA RMS
600A/S1/S1214
C = 670/800
40 mA RMS
600A/S1/S1214
C =670/800
50 mA RMS
600A/S1/S1223
C = 740/870
50 mA RMS
100A
600A/S2/P/
S1217
C = 470/540
70 mA RMS
600A/S2/P/S1215
C = 570/670
75 mA RMS
600A/S2/P/S1215
C =570/670
100
mA RMS
600A/S2/P/S1196
C =620/740
100 mA RMS
150A
600A/S3/P/
S1219
C = 430/500
100 mA RMS
600A/S3/P/S1220
C = 520/620
100 mA RMS
600A/S3/P/S1221
C = 570/670
100 mA RMS
600A/S3/P/S1222
C =620/740
100 mA RMS
In some situations single disc assemblies may be acceptable, contact General Electric for detailed applications.
Not
e:
The Metrosils recommended for use with 5 Amp CTs can also be used with triple pole devices and consist of three single pole
units mounted on the same central stud but electrically insulated from each other. To order these units please specify "Triple
pole Metrosil type", followed by the single pole type reference. Metrosil for higher voltage settings and fault currents are
available if required.
2.8 USE OF ANSI C-CLASS CTS
Where American/IEEE standards are used to specify CTs, the C class voltage rating can be used to determine the
equiv
alent knee point voltage according to IEC. The equivalence formula is:
V C rating in volts R
K CT
= +1 05 100. ( )
P24xM Chapter 9 - Current Transformer Requirements
P24xM-TM-EN-2.1 199