Above ground earthing PE-DG-327-509-E004 REV.01.pdf
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Transcript of Above ground earthing PE-DG-327-509-E004 REV.01.pdf
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1.0 TYPICAL SIZING CALCULATION FOR EARTHING CONDUCTORS OF PLANT AUXILIARIES
1.01
A=I= 50000.00 Amperes
tc= 1.00 SecA= 608.00 Square mm
Hence the Size chosen 65 x 10 mm is adequate
1.02 11 & 6.6 kV EQUIPMENT A=I= 50000.00 Amperes
tc= 1.00 SecA= 608.00 Square mm
Hence the Size chosen 65 x 10 mm is adequate
1.03
A=I= 50000.00 Amperes
tc= 1.00 SecA= 608.00 Square mm
Hence the Size chosen 65 x 10 mm is adequate
1.04 SUB-MAT, RUNWAY CONDUCTOR/MAIN EARTH LEAD ALONG COLUMNSA=I= 50000.00 Amperes
tc= 1.00 SecA= 608.00 Square mm
Hence the Size chosen 65 x 10 mm is adequate
1.05 415 V MOTORS
ABOVE 90 KW A=I= 50000.00 Amperes
tc= 1.00 SecA= 608.00 Square mm
Hence the Size chosen 65 x 10 mm is adequate
ABOVE 30 KW UPTO 90 KWA=I= 3000.00
tc= 0.20 SecA= 16.31 Square mm
Hence the Size chosen 25 x 3 mm is adequate
in Amperes = Effective Short circuit current for 0.2 sec pre-arcing time ( Refer enclosed fuse characterstics of siemens type 3 NA2)
NEUTRAL & ENCLOSURE EARTHING OF GENERATOR TRANSFORMER, STATION TRANSFORMER, LT AUXILIARY TRANSFORMER, LT BUSDUCT,
415 V SWITCHGEAR , MCCS , BATTERY CHARGER , DISTRIBUTION BOARDS, FUSE DISTRIBUTION BOARDS,
ctI ��01216.0
ctI ��01216.0
ctI ��01216.0
ctI ��01216.0 ctI ��01216.0
ctI ��01216.0 ctI ��01216.0 ctI ��01216.0
ctI ��01216.0 ctI ��01216.0 ctI ��01216.0 ctI ��01216.0
ABOVE 5 KW UPTO 30 KWA=I= 2000.00
tc= 0.20 SecA= 10.88 Square mm
Hence the Size selected 8 SWG GI wire is adequate
Upto 5 KWA=I= 600.00
tc= 0.20 SecA= 3.26 Square mm
Hence the Size selected 8 SWG GI wire is adequate
1.06 SYSTEM NEUTRAL
A=I= 50000.00 Amperes
tc= 1.00 SecA= 608.00 Square mm
Hence the Size chosen 65 x 10 mm is adequate
The maximum system neutral fault current is 50 kA of the 415 system, so that will be considered for calculations.
in Amperes = Effective Short circuit current for 0.2 sec pre-arcing time ( Refer enclosed fuse characterstics of siemens type 3 NA2)
in Amperes = Effective Short circuit current for 0.2 sec pre-arcing time ( Refer enclosed fuse characterstics of siemens type 3 NA2)
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ctI ��01216.0 ctI ��01216.0 ctI ��01216.0 ctI ��01216.0 ctI ��01216.0 ctI ��01216.0 ctI ��01216.0 ctI ��01216.0 ctI ��01216.0 ctI ��01216.0 ctI ��01216.0 ctI ��01216.0 ctI ��01216.0 ctI ��01216.0 ctI ��01216.0 ctI ��01216.0 ctI ��01216.0 ctI ��01216.0 ctI ��01216.0 ctI ��01216.0
ctI ��01216.0 ctI ��01216.0 ctI ��01216.0 ctI ��01216.0
