Wednesday, January 1, 2020

Types Of Electrical PAT Test

Types Of Electrical Pat Test
The test is carried out using an ohmmeter or a PAT tester;
Using The Ohmmeter To Produce A Reading
Use of a PAT tester under the following conditions
12 V maximum, test current range 100 MA to 200 MA - commonly known as "ground continuity test" or "screen test"
12 V maximum, test current 10 A - commonly known as "routine test"
12 V maximum, 1.5 times the rated current of the device or 25 A, whichever is greater - commonly called "type test" or "link test"
Image result for Low Current Continuity Test
Low Current Continuity Test:
A continuity measurement must be made using a short-circuit test current between 20-200 MA between the exposed conductive parts of the equipment and the earth pin of the plug (or the earth / earth terminal of the 'food). This test is performed using the ground wire. The maximum resistance value should be noted when flexing the active power cable and a visual examination of the power cable terminations at both ends should be made. Any fluctuation in reading should be studied to identify the cause. The test current is so low that there is no risk of damaging the ground connections which may exist for functional rather than safety reasons. This low current test is sometimes called a "flexible test".
High Current Link Test
A continuity measurement using a test current of max 26 A for between 5 and 20 seconds. This test is used when the user fears that earth could be held by a few strands of wire or when poor surface contact by the probes or clips could give a misleading reading. The bond test must be connected between the exposed grounded / grounded parts of the equipment and the grounding pin of the plug (or power grounding terminal). This is done by connecting the ground wire to the exposed hardware. The maximum resistance value should be noted when flexing the active power cable and a visual examination of the power cable terminations at both ends should be made. Any fluctuation in reading should be studied to identify the cause.
Insulation Test
The insulation test is used to confirm that there is a separation between the live conductors (live and neutral) and all accessible conductive parts. Generally, insulation tests are performed by applying a known test voltage (500 V DC) and measuring the resistance. On sensitive equipment (IT for example), 500 V can cause damage and therefore not suitable. Therefore, it can be replaced by a low voltage insulation test (250 V), a contact current test or another leakage current test. The devices must not be touched during an insulation test because, in the event of a fault, the exposed hardware may reach the test voltage, although this voltage in itself is not dangerous. It is carried out using an ohmmeter or a portable device tester by applying a nominal voltage to the live conductors (active and neutral) of a device and by placing a reference of 0 volts on the parts put to the earth of a class I appliance or the external metallic parts of a class. Device II.
The test method varies depending on whether the device is class I or class II. For a grounded device (class I), the insulation test is carried out between the ground pin and the combined live and neutral pins of the plug. Merger PAT test make these connections for you. A Class II device is slightly different since there is no connection to the ground pin of the plug. This time, a connection is established between the active and neutral pins combined and all the metallic parts or dirty / conductive areas of the housing which may require several tests. The connection method is the same as that used for grounding / continuity, using the same wire.
Differential Leak Test
The differential leakage current test (also called protective conductor current) measures the difference in current between the active and neutral conductors and determines whether a current flows to earth. Normally devices should have little or no earth leakage current. Class II devices (double insulated) may present earth leaks through their supports or through contact with the operator. During the test, the actual line voltage is measured at the device socket. To guarantee the safety of the equipment even when the mains supply reaches its maximum authorized value, the PAT calculates and displays the leakage current which would circulate at this value.
Image result for differential leak test
Leakage Current Test
It is performed at nominal voltage with values ​​not exceeding 5 Ma for class I devices or 1 Ma for class II devices.
Alternatively, measure the insulation resistance values ​​are not less than 1 MΩ for class I and class II devices at 500 V DC. or alternatively, to prevent the equipment apparently failing the test because the metal oxide varistors (MOV) or the suppression of electromagnetic interference (EMI) have been triggered, for equipment containing voltage limiting devices such as MOV or EMI suppression, at 250 V DC.
Leakage current tests are carried out using a PAT by applying a nominal voltage to the live conductors (active and neutral) of a device and by placing a 0 volt reference on the earthed parts d '' a Class I device or the external metallic parts of a Class II device.
Loading Test
The load test (also called function test or VA) measures the electrical consumption of the equipment in operation. Measuring the load (VA) of a device is a good indication of its operating state. By setting a VA load limit in the instrument test groups, a device can be automatically evaluated for excessive load. The VA load limit is generally defined on the basis of the nameplate of the device. When using the Meager portable device testers, which power the equipment for you, a functional test is performed during the "load" test. This test will determine:
If the asset is working properly
VA rating of the device
The results of this test can be a good indicator of future problems and potential device failures.
Problems such as worn bearings on a drill would likely increase the current drawn from the power supply and therefore increase the VA reading. Precautions must be taken
Polarity Check
In countries where the sockets are polarized, the polarity test is a simple test which can be carried out using a polarity tester to determine if the active and the neutral of the end of the plug are correctly connected to the corresponding terminals at the end of the socket
Note: Earth is tested during the earth continuity test. In the UK, according to BS7671, the phase cable ("Live" or "Hot") must connect to the right terminal of the socket (if we are facing the socket).
Flash Test
Flash tests measure the leakage current when high test voltages are applied to an asset. The flash test provides a high AC test voltage (2500 V or 3000 V) and measures the leakage current. This test can be destructive and is generally only used on repaired equipment. It is generally not used for "in service testing" of electrical equipment.
Labeling
All equipment requiring visual examination and electrical testing must be clearly labeled. The label must consist of a unique identifier of the equipment, the date of its test, the date of the new test and an indication of its condition. A broken element does not need dates, it is enough to clearly identify that it has failed. Labels can be filled in by hand or printed. Printed labels often consist of a bar code for the identifier, which makes them easy to read with an appropriate bar code reader. It is a great time saver with an instrument that supports it such as the PAT 400 series from Merger. Labels must be manufactured so that
Documentation
The following records must be established and kept up to date:
1:A register of all equipment
2:A register of formal and combined visual examinations and electrical tests
3:A register of all defective equipment
4:A repair register
All of these records may be stored on paper or electronically, as long as reasonable precautions are taken with regard to data protection. Whichever method is chosen, the results of previous tests must be available to the tester. Our company keeps the following paper or electronic documents. Copy of formal visual examination and combined visual examination and electrical test results and log of all repaired equipment.
Report
At the end of the tests, you will receive a security certificate and a detailed report providing information on each individual item. All items that pass inspection and testing will be labeled with a security sticker and a unique bar code number which helps us keep track of all the portable devices in your business. For more info click here

No comments:

Post a Comment