MI 2087 Instaltest 61557
Measurement instructions
17
3.2. Varistor Over-voltage Protection Devices
For general information concerning the measurement, refer to enclosed handbook
Measurements on electric installations in practice and theory
.
How to carry out the Breakdown voltage measurement?
Step 1
•
Connect Universal test cable to Instaltest 61557.
Note!
Set function switch to
Riso
position and press the
SELECT
key to enter the selection
menu. Use the
↑
and
↓
keys to select between “
ISO”
(Insulation resistance)
and
“tSt”
(Varistor Over-voltage Protection Devices)
functions. Press
SELECT
key when
“
tSt
” is displayed to enter the Varistor Over-voltage Protection Devices function. Press
the SELECT key twice to skip limit adjustment menus and to enter
Varistor test
initial
menu.
Fig. 8.
Varistor Test initial menu
Step 2
•
Set
High Limit Breakdown Varistor Voltage
. Later will test results be
compared with the set limit value and, if higher, they will be equipped with
“!”
mark.
How to set the High Limit value?
•
Press the
SELECT
key twice, to enter “High Limit value adjustment mode”, the
following menu will appear:
Fig. 9.
High limit value adjustment menu and the table of available limit values
Last set High limit value is blinking.
Available
values (V)
Step
(V)
0
÷
1000
10
