User Manual

34 GMC-I Messtechnik GmbH
Test Sequence
Attention!
!
Prerequisite for Testing
The measurement of insulation resistance may not be
co
nducted on protection class I devices which have not
passed the protective conductor resistance test.
Note
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 8.7).
Observe the notes in the service instructions.
Attention!
!
In order to prevent damage to the instrument, measure-
ment of insulation resistance
may only be performed be-
tween application parts, measurement inputs or
int
erfaces and the protective conductor or the housing if
the instrument 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
duri
ng measurement of insulation resistance, including
temperature controlled switches and temperature regula-
tors as well.
Measurement must be performed in all program steps
for devices equipped with program controllers.
Set the rotary switch to the R
ISO
position.
Select the measurement type and the test voltage.
Th
e 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 D
UT to the test socket.
S
tart the test: press the START/STOP key.
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 symbol shown at the right appears.
Each time
this key is pressed, the currently displayed
measured value is saved to the buffer.
Attention!
!
Removing the Connector Cable
Do not remove the DUT’s connector cable until the test
ha
s been stopped, in order to assure that the capacitors
have been discharged.
Stop the test: press the START/STOP key.
The save symbol appears (floppy disk showing the
number of measured values
stored to buffer memory)
and prompts you to save the measured values to an ID
number.
Read the measur
ed 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 Allowable Limit Values for Insulation Resistance
Tes t
Standard
Test Volta ge
R
ISO
LNPE
LN
Probe
Probe
PE
PC III Heating
VDE 0701-
0702:200
8
500 V
1 M 2 M 5 M 0.25 M 0.3 M *
DIN EN 60974-4
VDE 0544-
4:2009-06
2 M 5 M 5 M
* With switched on heating elements
(if heating power > 3.
5 kW and R
ISO
< 0.3 M: leakage current mea-
surement is required)
Test Standard
Test
Vo
ltage
R
ISO
PC I PC II
IEC 62353
(VDE 0751-1)
500 V
2 M 7 M
BF or CF BF or CF
70 M 70 M
Notes
Insulation resistance and/or leakage current must be measured
by contacting all exposed, conductive parts with test probe P1 for
protection class II and III devices, as well as for battery powered
devices.
Batteries must be disconnected during t
esting of battery powered
devices.
8.7 Measuring Leakage Current
Attention!
!
Measurement with DUT Connected to Line Voltage
It’s absolutely essential to assur
e 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 approx.
10 mA.)
Frequency response in
acc
ordance with the
figure to the right is
taken into consider-
ation for all leakage
curr
ent measure-
ments (IPE, IB, IG, IP)
(dir
ect, differential,
alternative).
10 10
2
10
3
10
4
10
5
10
6
+20
0
–20
–40
–60
Frequency (f) in Hz
Relative Magnitude (dB):
U(f)
U(f=10)