Thanks jghrist, I think you've summed up the situation succinctly. The only real calculation needed is to size my main earth ring cable to handle local LV faults. GPR, and therefore step & touch potentials are not a problem.
>>What is the source of power to the island?
The source of power is from barges moored adjacent to the island. Power is generated at 10 kV by 4 x 29.2 MW gas turbines, stepped up to 35 kV and transmitted to the islands via 35 kV cables. The barges' earth system is coupled directly to the...
I forgot to mention that the system voltage levels and earthing method:
- 35 kV resistively earthed (4 x 200 A neutral earthing resistors, maximum 800 A)
- 6 kV resitively earthed (20 A)
- 690 V resistively earthed (200 A)
- 400 V solidly earthed
I have a project earthing philosophy that calls for calculations to confirm touch & step potentials are within acceptable limits as per IEEE-80.
I am seeking advice on how to apply IEEE-80 to the following situations:
- indoor substation
- outdoor equipment
I am not sure on how to calculate...
