Megger PAT4DV/3, Руководство пользователя

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Description of Tests
Circuit Test. (Pre-Test)
Prior to performing any of the main tests an initial check is performed to indicate an approximate value of appliance loop impedance. Abnormal results
from this test displays a message indicating the conditions that may affect the validity of the tests to be performed, or where possible damage to the
PAT4 may result. When everything is in order, no message is given. The flowchart below shows the other possible displays.
• Open circuit - Check asset On/Off switch and /or fuse. • Short circuit - Check asset before continuing.
Note that some assets containing heating elements, filament lamps or very large motors may exhibit a very low resistance in their de-energised state,
causing
PAT4 to warn of a possible short circuit. In such cases, the warning can be ignored.
Note:
- If an operation test is carried out on a short circuit
asset, PAT4 may be damaged. If in doubt
DO NOT PROCEED
. Press the
FAIL
key, suitably label, and remove the asset from service; investigate and
rectify the fault, and re-test on completion. The asset is energised from a low potential / low energy a.c. supply. The open circuit voltage is typically 12
Volts (peak) with a short circuit current of 100 mA.
Insulation Test
A 500 Volt D.C. source is used to provide the Insulation test function. Class 1 appliances, are tested by applying 500V between Earth and the two-
phase conductors joined together. Class 2 appliances should be tested using the Bond test lead as a return connection. The insulation test voltage is
applied to the appliance phase conductors as for Class 1, but any current flow will return to Earth via the bond test lead which should be connected to
the appliance insulation or to any exposed metal parts. The insulation test has been designed to supply 500 V at 1 mA.
Operation Test
For an Operation test ensure that the asset is in a safe condition to run and that no hazards are present.
Operation tests allow the power consumed by the equipment to be checked against the manufacturers rating. The measurement is displayed in Volt
Amps (VA) often specified on assets as Watts.
During the Operation test the appliance is powered directly from the incoming mains supply (230V or 110V). During the test the PAT4 also measures
the mains voltage at the time of test. If this is found to vary from the nominal mains value (230 V or 110V) PAT4 will make a correction and display the
consumed power as if the mains voltage had been exactly correct. This enables a more accurate comparison with the manufacturers figure.
Pre-testing asset...
. . . .
Asset maybe O/C FAIL
RETRY IGNORE
Asset maybe S/C FAIL
RETRY IGNORE