As electricians who have worked in the Adelaide metro area for over 20 years, two of the most critical aspects of any electrical system that we always inspect and verify are the grounding and bonding components. Proper grounding and bonding provide a safe path to shunt electrical faults and over-voltages to the earth, protecting equipment, appliances and preventing shocks or fires. Without a robust grounding/bonding system in place, energised electrical components essentially have no safety net from catastrophic failures.
While often overlooked aspects, grounding and bonding requirements are mandated by electrical codes and standards for essential protection and performance reasons. Yet we’ve encountered far too many older properties with inadequate, ageing or completely lacking grounding and bonding due to original substandard installations or degradation over decades. Let me explain the importance of these electrical safeguards.
Purposes of grounding
The primary purpose of a grounding system is to limit the voltage caused by electrical line surges, faults or equipment failures by providing an intentional path of low impedance back to earth. Key components include:
- Grounding electrodes/rods driven into the soil
- The grounding electrode conductor running to electrical panels
- Circuit grounding conductors tied into this electrode system
- Bonding all grounded components like conduits, equipment frames, etc. together
By shunting dangerous fault currents, voltages and electrical noise to the stable earth ground, grounding protects equipment from damage and prevents electrical fires. It also stabilises the electrical system to ensure proper operation of overcurrent protection devices and controls.
For personnel safety, grounding creates a low-resistance path that prevents electrical faults from developing differences of potential between conductive surfaces which could shock or electrocute. Current flows directly into the ground instead of through a person’s body.
Purposes of bonding
While grounding routes faults/surges to earth, bonding is the interconnection between all grounded metal components and conductive surfaces. Done properly, bonding forms a continuous, unbroken path linking all non-current carrying metal parts together, polarising them to the same ground potential.
This prevents voltages from developing across different surfaces during fault events. It also prevents static electricity buildup and dangerous stray currents by allowing any electrical charges to be instantly neutralised through the low-resistance bonding connections.
Bonding is absolutely crucial everywhere from large industrial plants dealing with high fault currents to home swimming pools prone to lightning strikes. All metallic objects must be bonded together and to the grounding system without any discontinuities.
Inspection and testing
To ensure grounding and bonding systems are installed and functioning correctly, licensed electricians perform thorough inspection and resistance testing procedures:
- Visually inspecting all grounding electrode connections are clean, tight and corrosion-free
- Verifying all conductive surfaces like conduits, equipment frames, etc. are properly bonded
- Using specialised test equipment to measure the resistance to earth across the electrical system
- Confirming low resistance values align with codes and system performance requirements
For new construction and renovations, we carefully plan and install complete grounding grids from day one per approved electrical drawings. On older properties, grounding and bonding systems often need to be upgraded or completely replaced with new electrodes, conductors and inter-bonding components.
The dangers of improper grounding/bonding
When we encounter properties with grounding deficiencies, open bonding paths or high resistance faults, it dramatically increases electrical risks like:
- Increased potential for electrical shocks and electrocutions
- Possibility of electrical fires and arcing from fault currents
- Static charges causing damage to electronic components
- Unreliable operations of overcurrent devices and circuit protections
- Non-compliance with Australian/NZ wiring rules and safety standards
An ungrounded or improperly bonded electrical system is incredibly dangerous and leaves equipment, facilities and lives at severe risk during electrical faults, lightning strikes or transient overvoltages. As electricians, it’s one of our highest priorities to inspect and remediate any substandard grounding/bonding issues to the absolute latest codes and safety requirements.
Conclusion
While often overlooked compared to other electrical components, robust grounding and bonding are the foundation of any safe, reliable and code-compliant electrical system. Don’t take any risks – have an experienced, licensed Adelaide electrician regularly inspect and test your home or business’s grounding/bonding integrity. This critical electrical safeguard is worth the investment in protection.
