Main Earthing System: What Is Checked During an Electrical Safety Inspection?

The main earthing system is one of the most important safety components of a property’s electrical installation.

Earthing provides a path for fault current and helps protective devices operate when an electrical fault occurs. A problem with the main earthing conductor, earth electrode or its connections can create a significant electrical safety risk.

During an electrical safety inspection, the main earthing system is inspected and tested to determine whether it remains in a safe condition for continued use.

What Is the Main Earthing System? #

The main earthing system connects the electrical installation to earth.

It generally includes components such as:

• Main earthing conductor
• Earth electrode
• Main switchboard earthing connection
• Protective earthing conductors
• Earthing connections and terminations
• Relevant bonding connections

The exact arrangement can vary depending on the age and design of the electrical installation.

Why Is Earthing Important? #

If an electrical fault occurs, the earthing system helps provide a path for fault current.

A correctly functioning earthing system helps:

• Reduce the risk of electric shock
• Provide a suitable fault-current path
• Assist protective devices in operating correctly
• Maintain electrical safety throughout the installation
• Protect people from dangerous touch voltages

Because of its importance, the earthing system should only be inspected, tested or modified by an appropriately licensed electrician.

What Is Checked? #

During an electrical safety inspection, the electrician may inspect the main earthing system for signs of damage, deterioration, corrosion or poor connections.

The inspection can include checking that:

• The main earthing conductor is correctly connected
• The conductor is appropriately sized
• Connections are mechanically secure
• Connections are protected from damage and corrosion
• Earth electrode connections are accessible where required
• The main earthing conductor is continuous
• Required identification and labelling is present
• There are no obvious signs of deterioration

The original AS/NZS 3019 material referenced by Detector Inspector includes checks of the earth electrode, main earthing conductor, connections, accessibility, mechanical security, protection from corrosion and required labelling.

Earth Continuity Testing #

Visual inspection alone cannot identify every earthing problem.

Electrical testing can be used to verify continuity of the earthing system and other relevant electrical characteristics.

Energy Safe Victoria identifies continuity of the earthing system and earth resistance of the main earthing conductor, protective earthing conductors and bonding conductors among the mandatory tests used when verifying electrical installation work.

Testing helps an electrician determine whether the earthing system is performing as required.

Common Main Earthing Problems #

Some problems that may be identified during an inspection include:

• Loose connections
• Corrosion
• Damaged earthing conductors
• Poor connections at the earth electrode
• Incorrect or inadequate conductor sizing
• Missing or damaged identification
• Mechanical damage
• Deteriorated earth electrode connections
• Earthing conductors that are not correctly connected at the switchboard

Some of these defects may be hidden and require electrical testing to identify.

What About Older Properties? #

Older homes can have electrical installations that were constructed under requirements applicable at the time of installation.

For example, older properties may have used metallic water pipe arrangements as part of their earthing system. Changes to plumbing systems can affect these older arrangements.

The current electrical safety assessment needs to consider the actual installation and applicable requirements rather than assuming every property has the same earthing arrangement.

Main Earthing and Victorian Rental Properties #

Victorian rental providers must ensure an electrical safety check every two years by a licensed or registered electrician. The check covers the electrical installations, fixtures and fittings at the property.

Energy Safe Victoria states that the inspection and testing is intended, as far as reasonably practicable, to determine whether the installation and its constituent equipment are in a safe condition for continued use.

If an earthing defect is identified, the electrician should document the issue and recommend any required repairs or further investigation.

What If an Earthing Fault Is Found? #

A fault involving the main earthing system should be assessed by a licensed electrician.

Depending on the problem, corrective work may involve:

• Repairing a damaged conductor
• Replacing a defective connection
• Correcting an incorrect connection
• Addressing corrosion
• Repairing or replacing damaged components
• Further electrical testing

Electrical repairs should be carried out by an appropriately licensed electrical professional.

Don’t Alter the Earthing System Yourself #

The main earthing system is a critical electrical safety component.

Tenants, property owners and other unqualified persons should never disconnect, modify or repair the main earthing system.

If you notice a damaged earth conductor, loose connection, corrosion or other concern around the switchboard or earth electrode, arrange for it to be assessed by a licensed electrician.

Book an Electrical Safety Inspection #

Rental Safety Inspections provides professional electrical safety inspections for rental properties throughout Melbourne and surrounding areas.

Our licensed electricians inspect and test electrical installations, including switchboards, safety switches (RCDs), earthing systems, wiring, fixtures and fittings, to help identify electrical defects and safety issues that may require attention.

Contact Rental Safety Inspections today to arrange your electrical safety inspection.