Circutor MI-15KVe Guia Del Usuario página 24

4. The green GUARD( terminal is not always used. Technical Note 32 explains
the use of GUARD( terminal in order to minimizing the effect of stray resis-
tances. When measurement is carried out between parts which none of them is
grounded, (like between high-side and low-side windings of a transformer),
GUARD( terminal must be connected to ground in order to fix the apparatus
potential. At any time a measurement is performed, either the -R' or
GUARD( terminals must be connected to ground but never both simul-
taneously. If none of these terminals are connected to ground, the insulation
tester can reach a high potential that may result in an unstable non reliable
reading. If both terminals are simultaneously connected to ground, there is
a short-circuit between them and consequently the insulation tester will meas-
ure with error.
5. Turn on the apparatus by pressing the ON/OFF0 key. The ON LED+ begins
to bright.
6. Press the START KEY1. Then the high-voltage generator starts operating and
the corresponding indication light turns on at the front panel. The meter pointer
will indicate the value of the unknown resistance. If the element to be measured
is strongly capacitive it will initially indicate a low resistance value, which will be
gradually increased while the charging of that capacitance takes place. The
instrument will always begin in the scale A.
7. When the measured resistance exceeds the maximum value in range A, press
range B key, and if still the value is not achieved, press keys of ranges C or
Cx10, as required.
300
250
200
15
13 14
C
12
11
0,5
B
0,3 0,4
10
0,2
0, 1
A
0
400
500
1 .000
20
25 30
40 50
100
1
2
3 4
5
200
Icc=1mA
10
20
BATTERY
26
2.000
300