Electrical Ground Testing – Everything You Need To Know

Ground testing involves assessing the quality of ground circuits or electrical ground systems to meet the requirements provided by Standards Australia. Ground Testing concerns measuring the potency and performance of the systems ensuring they are allowing a low-resistance path for electricity to travel safely. A Level 2 Electrician is qualified to execute ground testing.

As ground circuits allow for electricity to travel in a safe manner towards the ground in the chance of accidents with bonding connecting the ground systems to the electrical systems. Evidently, ground testing is highly crucial. Ground systems of poor quality and not being bonded properly to their respected equipment/ electrical components in a location or site may result in the following:

• The expense of important data and equipment being lost or ruined
• Data of equipment not being processed correctly
• The catastrophic damage to human life, including the possibility of death
• Shock may lead to replacement or repair of parts/ equipment which are often costly and could have been avoided
• Destruction of electrical appliances and power outages

Evidently, grounding protects significant equipment, machinery and data from being disrupted or destroyed from surges in electricity. More importantly, it protects humans from being injured or even losing their lives by electrical surges. Hence, ground testing is extremely needed to determine if grounding within a residential, commercial or industrial building/ facility is of electrical standards by Standards Australia.

Reasons why your grounding and bonding systems may fail to work properly may be due to the following:

• Corrosion damaging connectors and rods
• Loosening of connections or bonds
• Incorrect materials applied in the beginning connection may fail (even if earlier it was sufficient)
• Rare cases the soil is contaminated with negative chemicals dissolving rods deeper within the ground

Since ground testing is important for the safety of your facility, electrical appliances and everyone around you, ground testing occurs in two times:

• Building – when the building process is undergoing, ground testing occurs. This ensures that the building being developed has the proper electrical system being installed. It also confirms that during the development if the chance for a power surge to occur, the workers and equipment involved are safe.
• Regular Checkups – once a building is finished, odd-intervals of 5, 7 or 9 months, recommended at least once a year, occur. During these times is when ground testing occurs to make certain that the systems are functioning correctly.

With these check-ups, Level 2 asp (authorised service providers) electricians are the qualified tradesmen to perform ground testing. They have the accurate knowledge and needed skills to undergo ground testing, as well as, experience when dealing with high voltage environments. An  electrician of lower authority will not have the insurance, qualification and most importantly knowledge to successfully and safely work in ground testing. This can lead to further damages and complications which could have been ignored/ avoided if utilising a level two electrician.

There are four types of methods with regards to ground testing with specific guidelines, standards and recommended steps when performing them:

• Soil Resistivity Test – this is the most common method when undergoing more recent and newly-installed systems. It involves using a ground resistance tester to test the soil’s resistance to electricity, as the various layers casing the resistance to vary. A device with 4 connecting lines attached to the ground connector is placed out in a straight line with equal distances of three times their length from each other. A controlled, known electrical current is then generated between the stakes on the outermost sides. The inner stakes generate a potential drop between themselves. Then using Ohm;s Law (V=IR) the drop in voltage potential is what determines/ calculates the soil’s resistance. This test can be used in different depths and directions if needed to view the resistance of other parts of the soil.
• Fall-of-Potential – this method is applied for both whole grounding systems or individual grounding stakes. This process measures the competence to dissipate electricity when higher voltages occur. The disconnection of the stake being tested begins followed by a testing apparatus being connected to the disconnected stake. This is given the name the ‘Earth Electrode’ which the other two stakes are placed in line and on the sides of the first electrode. A known current is then released firstly through the two outer stakes, then the Earth electrodes, occuring after the ground tester is connected with the other two stakes. This method is a bit more dangerous due to having to disconnect the earth electrode.
• Stakeless – this method is much safer than previous ones as there is no disconnections of electrodes and the search for locations of the stakes. It can be applied anywhere and involves setting up stamps close to the Earth Electrode or the connecting cable. These stamps let off known currents and are measured at the other stamp calculating the loop resistance. This method will, however, not work if only one path is available for electricity to pass.
• Selective – similar to fall-of-potential, this safe method does not need to disconnect the earth electrode from the site. Eliminating the effects of the parallel resistance, a clamp meter is fixed close to the earth electrode. The tester is connected to both the stakes (outer and inner – similar process like fall-of-potential) while also the stamp.