Benning IT 101, Operating Manual

Page: 21 / 119

03/ 2009
BENNING IT 101

15
Preset limiting values make it easier to evaluate the test.
5.1 General information concerning the insulation measuring instrument
5.1.1 The digital display
B
for the measurement readings
B
is a 3½-digit
liquid crystal display with decimal point. The height of the displayed
digits is 15 mm. The largest numerical value which can be displayed is
4000.
5.1.2 The bar graph display
B
consists of 49 segments and depicts resist-
ance readings on a logarithmic scale.
5.1.3 The polarity indication
Q
is automatic. Only one polarity with respect to
the socket marked ” - ” is indicated.
5.1.4 The digital display for the test voltage
M
is a 3½ digit liquid crystal
display with 7 mm high numerals. The largest value which can be
displayed is 1999.
5.1.5 Range overflow of the digital display
2
is indicated with the symbol ”>”
P
.
5.1.6 The BENNING IT 101 has an automatic measuring range selection
function (auto ranging).
5.1.7 The BENNING IT 101 is provided with an automatic background light-
ing ("Auto Backlight"). The brightness sensor is located on the top
side of the device
1
. As soon as the ambient lighting decreases, the
background lighting will switch on automatically.
5.1.8 An acoustic signal (buzzer) will sound once for each valid keystroke
and twice in case of an invalid keystroke.
5.1.9 The secondary function of the rotary switch position can be selected
by means of the key (blue)
3
. The low-pass filter (LPF) is activated
in switch position V. A compensation (null balance) of the measuring
leads is possible with switch position Ω ( ). The insulating resistance
or leakage current is indicated with switch positions 50 V/ 100 V/ 250 V/
500 V and 1000 V.
5.1.10 The COMP key
4
activates the comparative function for insulating
resistance measurement.
5.1.11 The STORE/ RECALL key
5
is intended for storage and call of meas-
ured values.
5.1.12 The key LOCK (latching)
6
permits continuous measurements of insu-
lating resistance and low-resistance without having to press the TEST
key
8
repeatedly or to hold it. To switch over to continuous measure-
ments, press the LOCK key and then the TEST key. The “LOCK”
symbol
D
appears on the display
2
. When measuring the insulating
resistance, pressing the TEST key continually applies the test voltage
to the measuring point. When measuring low-resistance, pressing the
key TEST continually applies the test current to the measuring point.
The locked state can be terminated by pressing the LOCK key or the
TEST key.

In locked mode (key) the BENNING IT 101 recognizes no
external voltage at the input of the instrument. Make sure that
the measuring point is free of voltage before activating the
locked mode, otherwise the fuse might blow.
The LOCK key activates the measurement of the dielectric absorption
rate (DAR)
K
and of the polarization index (PI)
L
.
5.1.13 The green LED
7
(PASS indicator) lights for the comparative function
(COMP key
4
), if the measured value exceeds the comparative value
(resistance value).
5.1.14. The TEST key
8
activates the measuring function for insulating resist-
ance and low-resistance.
5.1.15 The red LED
9
(  high-voltage control indicator) lights up, if a danger-
ous voltage is applied. The warning symbol 
R
is indicated on the
display
2
of the BENNING IT 101.
5.1.16 The BENNING IT 101 is switched on and off with the rotary switch
J
.
The off setting is ”OFF”.
5.1.17 The BENNING IT 101 switches itself off automatically after approx.
20 minutes. In locked mode (“LOCK”)
D
(continuous measurements)
automatic switch off takes place after 30 minutes. The instrument
switches itself on again automatically when a key is actuated, or the
measuring range selector switch is turned, or a voltage higher than
30 V AC/ DC is connected to the input of the instrument.
5.1.18 Temperature coefficient of the measured value: 0.15 x (stated measur-
ing precision)/ °C < 18 °C or > 28 °C, related to the value for the refer-
ence temperature of 23° C.
5.1.19 The BENNING IT 101 is powered by four 1.5 V mignon batteries (IEC
LR6/ type AA).