Gossen Metrawatt GmbH
53
Test Procedure
Attention!
!
Prerequisite for Testing
Measurement of insulation resistance may not be con-
ducted on protection class I DUTs which have not
passed the protective conductor resistance test.
The insulation test cannot be performed for all DUTs, for
example electronic devices, EDP equipment, medical
devices etc. Leakage current measurements must be
performed for these DUTs (see section 15.8).
Observe the notes in the service instructions.
Attention!
!
In order to prevent damage to the DUT, measurement of
insulation resistance may only be performed between ap-
plied parts, measurement inputs or interfaces and the pro-
tective conductor or the housing if the DUT is laid out for
measurements of this type.
Attention!
!
Touching the DUT During Measurement
Testing is conducted with up to 500 V, and although cur-
rent is limited (I < 3.5 mA), if the DUT is touched electrical
shock may occur which could result in consequential ac-
cidents.
Attention!
!
Switch Settings at the DUT
All switches at the DUT must be set to the on position
during measurement of insulation resistance – including
temperature controlled switches and temperature regula-
tors.
Measurement must be performed in all program steps
for devices equipped with program controllers.
➭
Set the rotary switch to the
R
INS
position.
➭
Select the measurement type:
– By setting the parameters
or
– Directly via the
Measurement Type
key
➭
Select the test voltage.
The
Up–
and
Up+
keys provide you with direct access to the
test voltage parameters: each time this key is pressed, the
setpoint value shown in the measuring window, Up(set), is re-
duced or increased by 10 V.
➭
Connect the DUT to the test socket.
➭
Start the test:
Press the
START
/STOP
key.
➭
Switch the device under test on.
Note
The measurement is disabled if a voltage of greater than
25 V is measured between the terminals.
➭
The measured values are displayed. The measured
value recording icon shown at the right appears. Each
time this key is pressed, the currently displayed mea-
sured value is saved to buffer memory.
➭
Turn off the device under test.
Attention!
!
Removing the Connector Cable
Do not remove the DUT’s connector cable until the test
has been stopped, in order to assure that the capacitors
have been discharged.
➭
End the test:
Press the
START
/STOP
key.
The save icon appears (floppy disk showing the num-
ber of measured values stored to buffer memory) and
prompts you to save the measured values to a test ob-
ject ID number.
➭
Read the measured values and compare them with the
table of permissible limit values.
➭
Press the
ESC
key in order to discard the measured
values stored to buffer memory and acknowledge by
pressing the key shown at the right.
Minimum Permissible Limit Values for Insulation Resistance
* With activated heating elements (where heating power > 3.5 kW and R
ISO
<
0.3 M
: leakage current measurement is required)
Notes
Insulation resistance and/or leakage current must be measured
for protection class II and III DUTs, as well as for battery powered
DUTs, by contacting all exposed conductive parts with test probe
P1.
Batteries must be disconnected during testing of battery powered
DUTs.
15.8
Measuring Leakage Current
Attention!
!
Measurement with DUT Connected to Line Voltage
It’s absolutely essential to assure that the device under
test is operated with line voltage during performance of
leakage current measurements with the direct or differential
current method
. Exposed conductive parts may conduct
dangerous touch voltage during testing, and may not
under any circumstances be touched.
Mains power is disconnected if leakage current exceeds
approximately 10 mA (can also be set to 30 mA).
Frequency response in
accordance with the
figure to the right is
taken into consider-
ation for all leakage
current measure-
ments (
IPE
,
IT
,
IE
,
IP
)
(direct, differential,
alternative).
Test Standard
Test Voltage
R
ISO
LN
PE
LN
Probe
Probe
PE
PC III Heating
VDE 0701-
0702 /
ÖVE E 8701 /
SNR 462638
EN 50678 /
VDE 0701
EN 50699 /
VDE 0702
500 V
1 M
2 M
—
0.25 M
0.3 M
*
IEC 60974-4 /
EN 60974-4 /
VDE 0544-4
2 M
5 M
5 M
Test Standard
Test Volt-
age
R
ISO
PC I
PC II
IEC 62353 /
EN 62353 /
VDE 0751-1
500 V
2 M
7 M
BF or CF
BF or CF
70 M
70 M
10
10
2
10
3
10
4
10
5
10
6
+20
0
–20
–40
–60
Frequency (f) in Hz
Re
la
tiv
e
m
a
gn
itud
e (
d
B
): 2
0
lo
g
U(f
)
U(f
=
10
)
Содержание SECULIFE ST BASE 25
Страница 111: ...Gossen Metrawatt GmbH 111 ...
