Kewtech KT64, Инструкция по эксплуатации, Страница: 19 / 44

16
7 . 2 2
Ω
Buzzer ( ) function
Use F 2 Button to enable / disable 2
Ω
Buzzer. Buzzer sounds when measured
resistance is 2
Ω
or less while this function is enabled. Buzzer does not sound
if it is disabled.
Warning: Ensure that circuits to be tested are not live.
Disconnect the instrument from the circuit under test before operating
the function switch.
To select the insulation resistance range select INSULATION .
8 . 1 . 1 The nature of insulation resistance
Live conductors are separated from each other and from earth metal by
insulation, which has a resistance which is high enough to ensure that the
current between conductors and to earth is kept at an acceptably low level.
Ideally insulation resistance is infinite and no current should be able to flow
through it. In practice, there will normally be a current between live conductors
and to earth, and this is known as leakage current. This current is made up of
three components, which are:-
1 . capacitive current
2 . conduction current, and
3 . surface leakage current.
Fig. 11
Continuity
8 Insulation