2. The S/S earthing system comprises of:
• A grid (earth mat)
Horizontal buried conductors
3. Functions of grounding system in the S/S
• Ensure safety of personnel due to electric shocks.
• Provide grounding path (Neutral grounding).
• Discharge over-voltages (ground path for surge arrestors).
• Provide path for faults (Phase-Ground).
• Provide earth connections to the non-current carrying objects in the
s/s.
4. Earthing Mat
• Buried below ground level
• Connected conductors
• If the soil have low resistivity>> the
earthing resistance will be low as well.
• If the soil have high resistivity>> Then we
need to insert more conductors in the
mesh and connect them closer (To create
lower resistance)
5. Earthing spikes (Electrodes)
• Driven into the ground: connected to the
earthing mat
Connect it to the; equipment
bodies, structures, neutrals, etc
6.
7. The fence, equipment
body, tanks, support,
structures, towers,
structural steelworks,
water pipes, etc. should
be earthed.
8. Earth Resistance Value
• Value of Earthing Resistance Determine the rise of the fault voltage!
• As well, limit the fault current
V = IR
9.
10.
11. Criteria of design S/S earthing system
• Low step voltage
• Low touch voltage
• Low earth resistance