METREL MI 3399, Инструкция с упражнениями

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PAT Appliances & Machines Safety Trainer AD 3
– MI 3399
224
Scope of test
See chapter 4.4.5 Leakage current tests
– general for more details.
Examples of faults
See chapter 4.4.4 Sub-leakage test for more details.
Figure 4-15: PE conductor leakage current test for Class I device
Measuring principle / limits
Measurement on Class I appliance:
Figure 4-16: Example of the PE conductor current test
The appliance must be powered on. The current flowing through the appliance PE
conductor is measured.
The appliance must be placed isolated against ground to prevent that a part of the
leakage current would flow directly to ground instead through the PE conductor and
ground. This is the main defectiveness compared to the differential leakage test.
Unearthed accessible conductive parts are not included in this test. They are considered
as class II parts and are checked in the Touch Leakage test.
Notes:

If leakage currents differ for different appliance operating modes all modes must
be checked. The highest result (it is the worst) must be considered!