PAT Testing – Earth Continuity Test

  • by Lyla Valli
  • 7 Months ago
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This test is transported on all Class I appliances during PAT Testing. The objective of the exam would be to make sure that there’s a great link between our planet pin around the plug and also the situation from the appliance. A great connection is understood to be getting a resistance of under .1 ohms (or 100 milliohms).

Our Planet Continuity test is sometime known as our planet Bond test or even the Earth Resistance test. Essentially all of them measure that there’s a great link between the mains plug and also the Earth point. The traditional way to handle this test would be to plug the applying right into a PAT Tester and clip the exam result in a appropriate earth point.

Once the test is performed, when the resistance measured is under .1 ohms, then there’s a great earth connection and also the appliance is recognized as safe. When transporting out this test during PAT testing, there are a variety of practical items to be considered.

Earth point on appliance

To be able to execute this test, it’s important obviously to clip the exam result in a appropriate earth point. If this isn’t done, then there’s no return path for that current during PAT testing. This can lead to the applying failing the exam.

Locating a appropriate earth point includes experience. It is important to obtain a good link with our planet point. Rusty metal or scaling on kettle elements prevents a great low resistance connection. If this sounds like the situation then rotate the connector and employ one’s teeth from the crocodile clip to scrape away the rust or even the scaling to obtain a good connection. It’s also acceptable to clip onto a screwdriver and employ this to connect with an Earth point.

The Golden Rule is: When testing Earth Continuity, should you choose obtain a fail initially, don’t immediately fail the applying. Make certain you’ve got a good connection and check out PAT testing again. If required consider using a different Earth point as not every metal parts may be linked to earth.

PAT testing – Class I Plastic appliances

On some Class I appliances it might not be easy to access an exterior earth point when the appliance is completely enclosed in plastic. For instance there are lots of electric fans being used which fall under this category. This presents us having a problem if we can’t connect the exam result in an earth point, there’s no circuit made and also the Earth Continuity test will fail.

On these appliances, you should recognise their construction means they are safer than conventional Class I metal appliances. In addition to getting an Earth connection, they basically are enclosed in plastic providing them with an additional layer of safety. The best way to execute PAT testing on these appliances would be to still perform Insulation Resistance Test. If the passes, then record this spread the gear Test Record making a comment towards the effect the earth Continuity test couldn’t be transported out because of the plastic enclosure.

PAT Testing – Test Current

The individual transporting the testing may use among the two options below.

Option 1: Make use of a test current of just one.5 occasions the fuse built in the plug up to and including more 25A. For instance, when testing a kettle having a fuse of 13A, an evaluation current of 25A ought to be used. When testing a lamp fitted having a fuse of 3A, an evaluation current close to 4.5A can be used. The present is generally applied for between 5 and 20 seconds. This test shouldn’t be utilized on IT or any other equipment where you can find electronic components being used. The big currents flowing on your lawn conductor is known to induce surge voltages which have broken electronic components.

Option 2: Make use of a test current which is between 20 and 200 mA. Although this test has been transported the cable ought to be flexed to create out any apparent problems. This is extremely safe test and could be utilized on ALL Class I appliances including IT equipment.

PAT Testing – Test Limits

As pointed out above, to pass through this test, our planet Continuity resistance needs to be under .1 ohm when PAT tests are transported out. Because this is in the pin around the plug towards the Earth point, an allowance can be created for that Mains lead which is used around the appliance. For instance, a category I lamp includes a 5m mains lead (current capacity of 3A) mounted on it. The entire resistance of the lead is .195 ohms. For this you might add some .1 ohms for that appliance itself to provide a restriction of .295 ohms. When testing this lamp for earth Continuity, when the resistance was say .22 ohms, the other would pass the applying. Say your personal computer includes a 5m cable of current capacity 13A. The entire resistance of the is .078 ohms. The pass limit with this PC could be .1 .078 that is .178 ohms.

When the appliance includes a short mains lead, this won’t lead a great deal to our planet resistance. For instance a 1m cable to have an electric fire might have a resistance of just .015 ohms. When utilizing a PAT Tester having a display, the consumer can exercise if the appliance passes or fails although taking the size of the mains lead into consideration. On Pass/fail PAT Testers, there’s a computerized allowance designed for the mains lead. Often the limit is placed close to .25 ohms to match as much as 5m of mains cable. On some Pass/Fail PAT Testers, allowance may also be designed for longer cables, say when testing 10m or 20m extension leads.

Bond testing is an integral part of the semi conductor and electronic construction industry. However, to ensure reliability of the results obtained, you can only rely on the best equipment for bond testing and they come from Xyztec. Axend is the company that provides Xyztec products in Singapore.

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