METREL MI 3399, Инструкция с упражнениями

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PAT Appliances & Machines Safety Trainer AD 3
– MI 3399
226
Unearthed accessible metal parts are not included in this test. They are considered as
class II parts and are checked in the Touch Leakage test.
Typical limits:
For limits and parameters see chapter 3.6 PE conductor leakage current test .
Measuring equipment designed according to VDE404 must have specified frequency
response from 40 Hz to 1 MHz (M characteristic).
Notes:

If leakage currents differ for different appliance operating modes all modes must
be checked. The highest result must be considered!

If the position of line and neutral conductor in the installation or appliance plug is
not predefined, the test must be performed in both directions with higher result
considered.

The differential leakage current test is preferred compared to the PE conductor test
since placing the appliance on conductive floor does not disturb the measurement
result.
4.4.8 Touch leakage test
Scope of test
The leakage (capacitive, resistive, fault) current is a current that would flow via the
isolated accessible metal part (if touched) through body to ground are measured in this
test.
Figure 4-19: Touch leakage current test for Class II device
Appliance must be powered on. The current through the isolated accessible metal parts
is measured (each part separately).
The measuring probe simulates the human body and is grounded inside the measuring
instrument.
Examples of faults
Fault:
Decreased insulation between live parts and isolated accessible conductive part
because of dirt, dust and moisture.
Result: Dangerous contact voltage on accessible conductive part. There is a risk of
electrical shock if this part would be touched.