KYORITSU 6011A - Manual (Page 25)

― 23 ―
8.2 What does the RCD test really do?
The RCD is designed to trip out when the difference between the phase current
and the neutral current (this is called the residual current) reaches the tripping
value (or rating) of the device. The tester provides a carefully preset value of
residual current depending on its setting and then measures the time lapse
between the application of the current and the operation of the RCD.
8.3 Uc Test
Ground being imperfect in the Fig11, when R exists, when fault current flows to
R, electric potential occurs. There is a possibility the person contacting in this
imperfect ground, it calls the voltage, which it occurs in the human body of this
time,called Uc.
When with the Uc Test letting flow I △N to the RCD, the Uc is calculated.
8.4 Uc Testing
1．Set the Function switch and select RCD.
2．Set the RCD rated tripping switch and select TEST CURRENT.
3．Make sure that "Uc" is displayed on the LCD after pressing the AUTO
NULL/Uc SWITCH.
Then. the result will be displayed by pressing the TEST BUTTON.
8.5 RCD testing
1．Set the RCD rated tripping switch to the trip rating of the RCD under test.
2．Set the function switch to X1/2 for the "no trip" test, which ensures that the
RCD is operating within its specification and is not too sensitive.
3．Press the phase selector switch to indicate 0
™
in the display.
Fig 11