Ss 551 Code Of Practice For Earthing -

The SS 551 Code of Practice for Earthing: Ensuring Electrical Safety

e. Touch Voltage for PV Solar Systems

• The 2018 edition does not adequately address floating PV systems (on reservoirs) or rooftop DC earthing. Clause 12 mentions “renewable sources” but lacks specific step/touch criteria for DC faults, which behave differently from AC.

• Main Equipotential Bonding: Connects main services (water, gas, AC systems) to the MET.
• Supplementary Bonding: Required in locations of increased shock risk (e.g., bathrooms, swimming pools) to connect exposed conductive parts and extraneous conductive parts simultaneously accessible.

Substation Interfaces: Managing the interface between LV and High Voltage (HV) substations within buildings. ss 551 code of practice for earthing

Periodic Inspection: Because soil conditions change and copper can corrode, the code mandates regular testing to ensure the resistance hasn't crept up to dangerous levels. The SS 551 Code of Practice for Earthing:

Example: For a 30 mA RCD, ( R_A \leq 50 / 0.03 = 1666 , \Omega ). But SS 551 recommends keeping below 200 Ω in practice. The 2018 edition does not adequately address floating

Corrosion Protection: Guidelines on selecting materials to prevent the degradation of earthing components over time.

Mandatory bonding applies to: