Megger PAT320-US – Portable Appliance Tester

Megger PAT320-US – Portable Appliance Tester

Applications

The PAT320 is used on the production line for final verification of electrical safety prior to general sale, or export to the EU. When exporting to Europe, it is the European importer’s responsibility to ensure imported items are safe to European standards. However, any testing performed at the destination can prove very costly for the US manufacturer when faults are found.

Testing at the manufacturing plant ensures electrical safety and provides the opportunity to fix faults and problems prior to shipping and export. For example, a poor ground connection would not normally be picked up during operational testing, and the PAT320 provides an excellent means of simple safety verification. The PAT320 is also suitable for use in the repair shop. Equipment can be checked on receipt in the shop before the technician powers it up, so ensuring he remains safe – the equipment could be in repair for any reason. Additionally, it can (and perhaps should) be checked prior to dispatch to make sure the ground bond remains good, and the phase connections remain isolated from the chassis following repair. This maintains full integrity of the repaired item before the customer receives it back.

Features and Benefits

• Simple push-button operation allows for direct access to tests via the keypad; no hidden menu functions.
• User selectable PASS/FAIL limits quickens test and simplifies results.
• Fast test times selectable from 1 second
• Combined bond and insulation lead thus reducing test time.
• High and low current bond testing (25 A, 10 A and 200 mA) is selectable either by default or individually per test
• Instant restart minimizes boot-up time when moving locations.
• Individual test mode keys allows for performance of any test by itself.
• Efficient bond transformer with heat dissipation increases productivity without overheating under heavy use.
• Test lead null enables the use of extended test leads without affecting the pass/fail limits or manually accounting for the added lead resistance.

Type of Tests

Earth Bond and Continuity Tests

To verify the integrity of exposed metalwork on grounded appliance (Class I). Test current of 25 A is passed via a remote probe, returning through the ground pin of the power plug.

Test currents of 10 A and 25 A are available for bond testing. Where sensitive electronic equipment may be damaged by high currents, 200 mA is selectable.

Insulation Test

To check equipment conductors are isolated from Earth – 500 V dc. The live and neutral conductors are linked, and the test voltage is applied between this link and the earth pin. Where an appliance does not have an earth connection (Class II), the remote probe is used to contact anywhere on the external case of the equipment. Where 500 V may damage sensitive equipment, the PAT320 provides alternative methods of verifying insulation integrity. A lower voltage of 250 V dc is selectable, or alternatives such as a Touch-Current or Substitute Leakage test can be performed. PAT320 Portable Appliance Tester

Touch Current Test

This test powers the asset at the supply voltage as if it were in use. The current passing down the earth conductor is displayed. For Class II, the remote probe is used to contact any accessible conductive parts.

Differential Leakage Test

Similar to the Touch Current test, during operation the difference in current between the live and neutral conductor is measured.

Substitute/Alternative Leakage Test

This test is performed in the same method as the insulation test, i.e. between the earth conductor and linked live/ neutral. For Class II, the remote probe is used to contact any accessible conductive parts of the asset.

A 50 Hz a.c. voltage (nominal 40 V) is applied and the leakage current measured. As this is at 50 Hz, the impedance of any leakage path is the same as that when the asset is in operation.

Functional Load Test

Operational test to ensure that the asset works as it should. Supply voltage is applied to the asset as in use. Simultaneously, the VA value is displayed as an additional check that the current drawn by the asset is as expected.

Extension and IEC Power Leads

Standard insulation and earth-bond tests are performed, with an additional polarity test to ensure that the lead is wired correctly.