ThePunisher
Electrical
- Nov 7, 2009
- 384
WE have a substation grid designed as per IEEE Std. 80-2000. The primary is a 69 KV 300A resistance grounded and secondary is 4.16kV, 25A resistance grounded. The substation is feeding a remote (2 kM electrical mobile equipment via trailing portable power cable (SHD-GC).
I perceive that the calculated GPR at the substation is like the "sending voltage" to the transferred potential at the mobile electrical equipment and the ground wire inside the trailing cable would be series zero sequence impedance to the persons body accidentally touching the metal-metal at the mobile equipment. In this regard, the voltage across the person's body would be a voltage drop calculated via voltage divider circuit. Hence, the transferred potential = (GPR at substation) - (ground wire voltage drop). The current flowing into the ground wire (inside trailing cable) and person's body would be a split from the ground fault injected to the substation grid (current divider).
Is this perception correct to calculate the transferred potential at the mobile equipment connected by a trailing cable?
My colleague informed me that the transferred potential is other way around by saying that it is the sum of the GPR plus the voltage induced into the ground wire...so now I am confused.
I would appreciate any expert advise and reference to any section of any industry standard.
Thanks!
I perceive that the calculated GPR at the substation is like the "sending voltage" to the transferred potential at the mobile electrical equipment and the ground wire inside the trailing cable would be series zero sequence impedance to the persons body accidentally touching the metal-metal at the mobile equipment. In this regard, the voltage across the person's body would be a voltage drop calculated via voltage divider circuit. Hence, the transferred potential = (GPR at substation) - (ground wire voltage drop). The current flowing into the ground wire (inside trailing cable) and person's body would be a split from the ground fault injected to the substation grid (current divider).
Is this perception correct to calculate the transferred potential at the mobile equipment connected by a trailing cable?
My colleague informed me that the transferred potential is other way around by saying that it is the sum of the GPR plus the voltage induced into the ground wire...so now I am confused.
I would appreciate any expert advise and reference to any section of any industry standard.
Thanks!