Get an Idea of What You Can Test Using PAT Equipment
PAT, also known as portable appliance testing, is the process of testing electrical appliances to check whether or not they adhere to Australian safety standards. Before PAT, an initial visual test is performed to inspect the condition of the electrical equipment and cabling. Then, tests such as grounding continuity, contact with exposed metal and standard insulation resistance tests are performed.
There are a few different types of test and tag equipment used to perform these tests, and all of them are made specifically for ascertaining safety levels. Most PAT equipment doesn’t allow for mains power connectivity. The most common type of testing equipment for PAT are basic, user-friendly pass/fail testers. However, there are also advanced testers that provide a lot more data.
How Is PAT Performed?
The grounding test allows you to verify the connectivity between the protective earth pin and exposed metal parts in the mains plug of class 1 appliances. This test involves connecting the electrical equipment to the test and tag equipment, and the test probe to the exposed metal parts. Then, a current is transferred to the PAT device along the mains cord and onto the enclosure. The current then goes back to the tester through the protective earth conductor, resulting in the display of the protective earth path resistance.
Insulation testing is performed by connecting the appliance to the tester. Then, a test voltage of 500 DC is applied to the mains plug terminals, resulting in a high-resistance reading being displayed on the tester. If the insulation is insufficient between the earth and the live parts, you’ll get current flowing from the insulation to the tester through the protective earth conductor. The low levels of insulation will then also be highlighted in the testers reading.
The testing of predicative conductor current is performed by connecting the appliance to the tester and powering the appliance. This results in a current flowing through the mains supply via neutral and live conductors. The currents going through should be neutral. If there’s an imbalance in the currents, the tester will highlight it on the screen.
Types of PAT Equipment
PAT equipment has a few different levels of functionality. The most basic pass/fail testers are relatively inexpensive and simple to use. They’re suitable for a wide range of industries, indicating whether the electrical appliance has passed or failed. On the other hand, there are mains-powered testers that require an electrical supply connection.
There are also battery versions which are suitable for large workplaces thanks to their ease of use and portability. These versions come with basic light systems that indicate whether the tested electrical equipment passed or failed the test. Most basic models allow for the establishment of insulation resistance, polarity and earth continuity, and are ideal for those who just want to obtain electrical test results easily and quickly.
On the other hand, advanced models allow for portable RC lead testing, fuse testing, lead polarity testing, adjustable pass test limits, mains and substitute powered leakage testing, etc. Some advanced models are quite affordable and user-friendly, allowing you to quickly take and record test results.
However, most of them lack the functionality for configuring test parameters. Most advanced testers are only useful to users with high levels of expertise and technical knowledge. They’re especially useful to facility management, as they let you record the location and test status of electrical equipment and appliances. Some of these testers also allow you to transfer the results of the tests to a smart device for digital interpretation, and you can maintain the results using PAT software.
What Can You Test With PAT Equipment?
The electrical category and class of the electrical equipment you want to test are the two key factors to the requirement of the PAT. The testing should be carried out according to the appliance classes outlined in the IET code of practice. This refers to electrical equipment supplied at voltages up to 1500V DC or 1000V AC between conductors or 900V DC or 600V AC between earth and conductors.
The categories defined within the IET code of practice include handheld equipment or appliances, portable equipment, movable equipment, stationary appliances or devices, fixed appliances or equipment, IT equipment, equipment or appliances for building in, RCD extension leads and extension leads, and RCD and multi-way adaptors.
Equipment such as monitors, electric drills, PCs and kettles can all be tested. All electrical appliances fall under category 1, 2 or 3. Appliances rated at category 1 are the most dangerous, and those rated at 3 are the least dangerous. The rating of the electrical appliance has a direct bearing on the need for PAT. You need to make sure all appliances in category 1 are tested. Appliances rated in category 2 only require insulation testing, and those rated in category 3 don’t require any type of testing.
