Gossen MetraWatt METRALINE PAT User manual

Operating Instructions
METRALINE PAT
Test Instrument for DIN VDE 0701-0702 3-447-022-03
2/4.19

2GMC-I Messtechnik GmbH
Table of Contents
Page Page
1 Safety Precautions .....................................3
1.1 General ................................................................3
1.2 Meanings of Symbols on the Device .......................4
1.3 Meanings of Symbols in the
Operating Instructions ...........................................4
2 Applications ...............................................5
3 Standard Equipment and Accessories .......5
3.1 Scope of Delivery ..................................................5
3.2 Accessories ..........................................................5
4 Connection, Control and Display Elements 6
5 Functions Description ................................7
5.1 Power Supply .......................................................7
5.2 Measurement Data Processing ..............................7
5.3 USB Port ..............................................................7
5.4 Bluetooth Interface ................................................8
6 Checking the Mains Connection ................8
6.1 Connection Display ...............................................9
6.2 Single-Phase Mains Connection .............................9
7 Display and Menu Structure ......................9
8 Initial Startup of the Test
Instrument .................................................9
8.1 Visual Inspection ...................................................9
8.2 Mains Connection .................................................9
8.3 Selecting and Starting a Test .................................9
9 Data Transmission ...................................10
9.1 Transmitting Measured Values to the PC ..............10
10 Single Measurements ..............................10
10.1 RSL / RPE – Protective Conductor Resistance .......11
10.1.1 Connection Type Selection ..............................11
10.1.2 RPE – Connecting Protection Class I Devices
to the Test Socket ..........................................12
10.1.3 RPE – Permanently Connected DUTs ...............13
10.1.4 RPE – Probe-Probe Measurement ...................14
10.1.5 RPE – Balancing the Probe Cable for the
Protective Conductor Measurement .................15
10.2 RISO – Insulation Resistance ................................16
10.2.1 RISO – LN-PE ................................................17
10.2.2 RISO – LN-Probe ............................................18
10.2.3 RISO – Probe-PE ............................................19
10.2.4 RISO – Probe-Probe (GND) ..............................20
10.2.5 RISO – L-N ....................................................21
10.3 IEA – Equivalent Leakage Current Measurement ....22
10.3.1 IEA – LN-PE ....................................................23
10.3.2 IEA – LN-Probe ...............................................24
10.3.3 IEA – Probe-Probe (GND) ................................. 25
10.4 AKTIV - Function Test and Leakage Current
Measurements ...................................................26
10.5 U – Testing the DUT (ELV) in the Presence of Line
Voltage ..............................................................27
11 Error Messages, Troubleshooting ........... 28
11.1 Display is Off ......................................................28
11.2 Touch Current Measurement Indicates 0.000 mA . 28
11.3 Touch Current Measurement Greater than 0.5 mA 28
11.4 “F” Displayed for Differential Current
Measurement .....................................................28
11.5 Bluetooth Communication ................................... 28
12 Technical Data ........................................ 29
13 Maintenance ........................................... 31
13.1 Housing .............................................................31
13.2 Recalibration ......................................................31
13.3 Technical Safety Inspections, ..............................31
13.4 Return and Environmentally Sound Disposal ......... 31
14 Repair and Replacement Parts Service ... 32
15 Product Support ...................................... 32

GMC-I Messtechnik GmbH 3
1 Safety Precautions
1.1 General
The METRALINE PAT test instrument has been
manufactured and tested in accordance with
the following safety regulations:
• DIN EN 61010-1 (VDE 0411, part 1),
“Safety Requirements for Electrical
Equipment for Measurement, Control,
and Laboratory Use, General Require-
ments”
• Interference immunity in accordance with
DIN EN 61326, “Electrical equipment for
control technology and laboratory use –
EMC requirements”
Safety of the inspector, as well as that of the
test instrument and the device under test, is
only assured when used for intended pur-
pose.
Read the operating instructions carefully and
completely before placing your test instrument
into service. Follow all instructions contained
therein. Make sure that the operating instructions
are available to all users of the device.
Tests may only be performed by a qualified elec-
trician, or under the supervision and direction of a
qualified electrician. The user must be instructed
by a qualified electrician concerning performance
and evaluation of the test (see also training semi-
nars listed at www.gossenmetrawatt.com).
In order to maintain safety and ensure safe oper-
ation, the user must observe the following warn-
ings:
Observe the warnings on the test instrument
and on the mains adapter cables!
Warning: Voltage!
The instrument may only be con-
nected to electrical systems with a
maximum of 230 V which comply
with applicable safety regulations
(e.g. IEC 60346, VDE 0100) and are
protected with a fuse or circuit
breaker with a maximum rating of
16 A.
Warning: Voltage!
Measurements within electrical sys-
tems are prohibited.
Attention!
!
Before connecting a DUT,
absence of voltage in the protective
conductor at the connection must be
verified by touching the finger con-
tact. The LED must not blink. It must
also be verified that < 30 V appears
in the connection menu.
Warning: Voltage!
No measurements may be con-
ducted on unfused measuring cir-
cuits.
The test instrument may no longer be used if
safe operation is not possible, e.g. due to
– Visible damage
–Improperstorage
– Improper transport
– Phase indicator lamp failure
– Failure of measuring functions etc.
The test instrument must be removed from
service immediately and secured against
inadvertent start-up.
Attention!
!
Protective conductor resistance and
touch current measurements in elec-
trical systems are only permitted
under certain conditions and after in-
stalling appropriate hazard warnings.
Warning: Voltage!
It must be observed that high volt-
ages can occur at test objects, e.g.
due to charged capacitive circuits.
Warning: Voltage!
Do not touch the insulation measur-
ing instrument’s test probes during
insulation resistance or equivalent
leakage current measurements.

4GMC-I Messtechnik GmbH
Warning: Voltage!
Do not connect the device under test
to the test socket until it has been as-
sured that the mains connection is in
safe working order.
Warning: Voltage!
Dangerous contact voltage may be
present at defective DUTs when
they’re connected to a test socket, or
at accessible conductive parts that
are not connected to the protective
conductor.
Opening the Instrument / Repairs
The test instrument may only be opened by
authorized, trained personnel from GMC-I
Service GmbH in order to ensure flawless
operation and to assure that the guarantee is
not rendered null and void.
Even original replacement parts may only be
installed by GMC-I Service GmbH.
If it can be ascertained that the test Instru-
ment has been opened by unauthorized per-
sonnel, no guarantee claims can be honored
by the manufacturer with regard to personal
safety, measuring accuracy, compliance
with applicable safety measures or any con-
sequential damages.
1.2 Meanings of Symbols on the Device
300 V CAT II Maximum permissible voltage and
measuring category between con-
nections and ground
Warning concerning a point of
danger (attention: observe docu-
mentation!)
The device may not be disposed
of with household trash.
Further information regarding the
WEEE mark can be accessed on
the Internet at www.gossenme-
trawatt.com by entering the
search term “WEEE”.
European conformity marking
1.3 Meanings of Symbols in the
Operating Instructions
General Notes:
Note!
General warning concerning a point of
danger!
Attention!
!
Warning regarding dangerous electrical
voltage:
Warning: Voltage!
!

GMC-I Messtechnik GmbH 5
2 Applications
The METRALINE PAT tester is a measuring
instrument for checking the effectiveness of
protective measures in electrical devices in
accordance with DIN VDE 0701-0702.
3 Standard Equipment and Acces-
sories
3.1 Scope of Delivery
1METRALINE PAT test instrument
1 Red measurement cable with safety plug
and test probe, 2 m
1 Mains power cable with inlet plug, with
earthing contact – IEC 60230, 16 A,
1.5 m
1 Factory calibration certificate
3.2 Accessories
VL2E (Z745W)
Test adapter with single and 3-phase plug
connectors up to CEE 32A
– For all tests without line voltage at single
and 3-phase electrical devices
– For tests at single and 3-phase extension
cords
Z745G brush probe

6GMC-I Messtechnik GmbH
4 Connection, Control and Display Elements
1 Mains connection, IEC 60320 C19
2 Test socket
3 Glow lamp indicates
“line voltage at the test socket”
4USBportforPC
5 Socket for red measurement cables
6 Socket for black measurement cables
7 Finger contact
8 LED for finger contact
9 Operating keys for single measurements
and function test
:Start measured value transmission
10 : Parameter selection
: Parameter settings
: Reset: repeat measurement
: Reverse polarity N/L: change polarity
: Standby : switch to mW measurement
OK: Start measurement
11 LCD
12 Good LED
13 Error LED
14 Ready to transmit
test results
Mains Connection (1), Finger Contact (7, 8)
The corresponding warnings in section 1,
the warnings on the mains adapter cables
and the warnings on any utilized accessories
must be observed before connecting the
test instrument to line voltage. Safety of the
operator, as well as that of the instrument
and the device under test, is only assured
when used for intended purpose! Protective
conductor potential testing is conducted via
the finger contact (7, 8) after connecting the
test instrument.
Mains Connection with Earthing Contact (1)
The test instrument may only be connected
to electrical systems with a maximum of
230 V which comply with applicable safety
regulations (e.g. IEC 60346, VDE 0100) and
are protected with a fuse or circuit breaker
with a maximum rating of 16 A.
Test Socket (2)
Earthing contact outlet up to 16 A. The test
socket’s protective conductor is connected
to the mains protective conductor and is dis-
connected from the mains when measuring
RSL, RISO and IEA. If the LED (3) lights up
red, line voltage is present at the test socket.
2
1
4
56
8
7
10
9
11
12
13
3
14

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Attention!
!
Dangerous contact voltage may be
present at defective DUTs when
they’re connected to a test socket, or
at accessible conductive parts that
are not connected to the protective
conductor.
USB Port (4)
Connection of a USB B plug for control from
the PC via a virtual COM port. Drivers sup-
plied by Future Technology Devices Interna-
tional Ltd. (FTDI) must be installed. These are
installed to the PC along with the software.
Red Measurement Socket, “Probe” (5)
The measurement cable is connected when
measuring protective conductor resistance
and insulation resistance. Measuring input
for measurement of voltage, equivalent leak-
age current and touch current.
Black Measurement Socket, “GND” (6)
Connection of an optional measurement
cable for measuring protective conductor
resistance, touch current, voltage and insu-
lation resistance with the Probe-Probe set-
ting.
Control Elements (9, 10)
All measurements can be selected and
started manually using the control elements.
Display (11)
The display has a resolution of 320 x 240
pixels and is backlit. All information (user
prompting, help texts) and measurement
results (measuring functions, limit values,
measured values and units of measure) are
displayed in plain text.
5 Functions Description
5.1 Power Supply
The device is powered by mains voltage
(230 V 10%).
The measuring electronics are protected by
means of an internal fuse.
5.2 Measurement Data Processing
Measured values are stored at a PC.
5.3 USB Port
USB port for service and remote operation:
The PC is connected via a standard type AB
USB cable.
The FTDI driver is installed along with the
software.
The transmission rate is 19,200 baud. The
interface is electrically isolated.

8GMC-I Messtechnik GmbH
5.4 Bluetooth Interface
The Bluetooth interface is used to transfer
measurement data.
The METRALINE PAT test instrument is
equipped with a Bluetooth module for wire-
less communication in a Bluetooth environ-
ment, which is permanently switched on.
Configure the following parameters in order
to establish communication between the
METRALINE PAT and the PC:
– Set the Bluetooth interface to “visible”
and/or “ready to pair”.
– Activate “Bluetooth” under settings.
– Select the device with the same serial
number as the measuring instrument for
initial pairing/use under available, addi-
tional devices or other devices.
– If applicable, the system may require a
password for pairing: enter either “0000”
or “8888”.
Note!
Designations used here may vary
depending on the device, the operat-
ing system and the software version.
6 Checking the Mains Connection
In accordance with the legally applicable
requirements (accident prevention regula-
tions, valid standards), the operator is
responsible for the safety of electrical sys-
tems (including on-site electrical connection
and equipotential bonding).
Testing of the electrical connection is not
included in the test specifications for modifi-
cation, testing and periodic testing of electri-
cal devices. However, it’s important to know
that the mains connection is in good work-
ing order before testing electrical devices.
The test instrument does not check the elec-
trical connection in accordance with the
specifications set forth in DIN VDE 0100.
Nevertheless, important and useful mea-
surements which provide information con-
cerning the electrical connection are made,
for example:
– Mains protective conductor potential test
via finger contact
– Mains protective conductor potential
PE < 30 V
– Testing of the N conductor for interrup-
tion (display remains off)
– Phase indicator lamp display when the
relay is picked up
– Voltage measurement, phase to N (dis-
play: 1 to 260 V AC).
Note:
– First of all it must be determined whether
or not the protective conductor is con-
nected by touching the finger contact. If
the red LED blinks, the protective con-
ductor is not connected. If the protective
conductor connection is not OK,
“PE > 30 V!!” appears at the display. This
is also indicated acoustically.
– No further measurements may be con-
ducted with the test instrument until after
the protective conductor has been suc-
cessfully repaired.
– If N and PE are reversed, the on-site
residual current circuit breaker is tripped.
– If no display appears, voltage may also
be present at PE. Check this using the
finger contact on the test instrument,
unplug the test instrument and then

GMC-I Messtechnik GmbH 9
check again at another power outlet. If
the device works at the second outlet,
arrange to have the first outlet checked
by a qualified electrician.
– When used in IT networks, and if the test
instrument is connected via an isolating
transformer, there’s no PE connection:
“PE > 30 V!!” appears at the display.
6.1 Connection Display
Available line voltage and the quality of the N
and PE conductor connections are dis-
played in the first “Connection” menu.
The finger contact LED can be checked for
correct functioning by touching the finger
contact with the probe during the
“IEA LN-Probe” single measurement. The
LED must blink.
6.2 Single-Phase Mains Connection
Attention!
!
If voltage L1 is less than 207 V or
greater than 253 V (L1 < 207 V or
L1 > 253 V), reliable and meaningful
measurements are no longer possi-
ble.
If “PE > 30V!!” appears and the dis-
play, the protective conductor is
most likely interrupted or, under cer-
tain circumstances, interference volt-
age may also be present at the
protective conductor (check via fin-
ger contact: respective LED must not
blink). Refer to section 6 with regard
to testing the protective conductor.
7 Display and Menu Structure
User prompting, measuring functions, limit
values and measured values appear conve-
niently at the display.
8 Initial Startup of the Test
Instrument
8.1 Visual Inspection
• Observe the safety precautions in sec-
tion 1.
• Visually inspect the mains connection,
the test instrument and any measuring
accessories.
• Observe the warnings on the test instru-
ment, the mains adapter cable and the
measuring accessories.
8.2 Mains Connection
The test Instrument is supplied with power
via the mains connection on the top of the
instrument.
8.3 Selecting and Starting a Test
The single tests (measurement type) are
accessed via the direct selection keys (9). A
menu for selecting the type of connection
appears. The corresponding start menu is
displayed after acknowledging with OK, and
the measurement is started at the same
time.
Depending on the type of measurement and
connection, the measured value is com-
pared with the limit value according to the
standard. If the standard value is complied
with, OK appears at the display and the
LED lights up green.
You can repeat the measurement by press-
ing the scroll key (reset), after which the
LED goes out.

10 GMC-I Messtechnik GmbH
9 Data Transmission
9.1 Transmitting Measured Values to the
PC
After pressing the key, the respective
measured value is initially transmitted via the
Bluetooth interface to an Android device to
which ELEXONIQ has been installed (Android
app for METRALINE PAT). The data can be
subsequently transferred from the Android
app to a PC, where they can be imported
into IZYTRONIQ report generating software.
10 Single Measurements
The following single measurements are
started with the help of the measuring func-
tion keys on the test instrument.
Key Function
RSL/RPE Protective conductor resistance
measurement
RISO Insulation resistance measure-
ment
IEA Equivalent leakage current
measurement
AKTIV Function test, standby test,
touch current measurement
(direct and differential method),
protective conductor current
measurement
(differential method),
Differential current measurement
(always includes touch current
measurement)
UVoltage measurement,
probe-probe
Transmitting measured values to
the PC

GMC-I Messtechnik GmbH 11
10.1 RSL / RPE – Protective Conductor Resistance
Definition
Protective conductor resistance is the sum
of the following resistances:
• Connector cable or device connector
cable resistance
• Contact resistance at plug and terminal
connections
• Extension cord resistance if applicable
Resistance is measured:
• Between each exposed conductive part of
the housing and the earthing contacts at
the mains and the device plug (if a
removable mains connector cable is
used), or the protective conductor termi-
nal for permanently installed devices.
•
Between the earthing contacts at the
mains plug and the earthing contacts at
the device plug for device connector cables
• Between the earthing contacts at the
mains plug and the earthing contacts at
the coupling socket for extension cords
Maximum Permissible Limit Values for the
Protective Conductor Resistance of Con-
necting Cables up to 5 Meters Long per
DIN VDE 0701-0702:2008
1This value may not exceed 1 for permanently
connected data processing systems (DIN VDE 0701-
0702).
2Total protective conductor resistance: max. 1 
Notes
Insulation resistance and/or leakage current
must be measured at all exposed, conduc-
tive parts for protection category II and III
devices, as well as for battery powered
devices.
Batteries must be disconnected during test-
ing of battery powered devices.
10.1.1 Connection Type Selection
Plug See section 10.1.2
Permanent
connection See section 10.1.3
Probe-probe See section 10.1.4
Rsl balancing See section 10.1.5
Test Curren t Open-Circuit
Voltage
RSL
Housing – Mains
Plug
> 200 mA 4 V < UL< 24 V
0.3 1
+ 0,1 2
for each addi-
tional 7.5 m

12 GMC-I Messtechnik GmbH
10.1.2 RPE – Connecting Protection Class I Devices to the Test Socket
When the DUT is connected, resistance is
measured between the protective conductor
terminal at the test socket and the probe
connection at the DUT (contact with con-
ductive parts of the housing).
➭In order to measure protective conductor
resistance, use the probe to contact a
conductive part of the housing which is
connected to the protective conductor.
During measurement, the connector cable
must only be moved to the extent to which
it’s accessible during repair, modification or
testing.
If a change in resistance occurs during the
manual test step of the continuity test, it
must be assumed that the protective con-
ductor is damaged, or that one of the con-
nector contacts is no longer in flawless con-
dition.
Connection
➭Connect the probe to the red probe
socket.
➭Insert the test object’s mains plug into
the test socket.
➭Switch the device under test on.
Procedure
➭Press the RSL key.
➭Select the “Plug” menu with the help of
the  scroll keys.
➭ Start the measurement by pressing the OK
key .
➭Review the preconfigured parameters for
cable length and cross-section, select
them if necessary using the scroll
keys and adjust them to the momentary
value using the  scroll keys.
Adjusting the cable length and cross-section
parameters changes the limit value which is
shown at the top of the display.
➭Contact the DUT’s housing with the
probe.
➭In the case of moving parts, for example
with a drill, contact the drill chuck while
it’s rotating – preferably with the optional
brush probe.
➭Move the mains power cord.
➭Contact all parts connected to PE with
the probe.
➭If the respective measured value is
smaller than the specified limit value, this
is indicated acoustically, OK appears at
the display and the LED lights up
green.
➭You can repeat the measurement by
pressing the scroll key (reset), after
which the LED goes out.

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10.1.3 RPE – Permanently Connected DUTs
In the case of permanently connected
devices: supply the test instrument with volt-
age from the DUT’s electrical circuit if possi-
ble.
In this way, PE is measured via the test
instrument’s mains connection, the installa-
tion in the system and the DUT’s mains con-
nection.
For this reason, the limit value is higher than
it is in the case of direct measurement.
Connection
➭Connect the probe to the red probe
socket.
➭Switch the device under test on.
Procedure
➭Press the RSL key.
➭Select the “Permanent Connection” menu
with the help of the  scroll keys.
➭ Start the measurement by pressing the OK
key.
➭Contact the DUT’s housing with the
probe.
➭Move the mains power cord.
➭Contact all parts connected to PE with
the probe.
➭If the respective measured value is
smaller than the specified limit value, this
is indicated acoustically, OK appears at
the display and the LED lights up
green.
➭You can repeat the measurement by
pressing the scroll key (reset), after
which the LED goes out.

14 GMC-I Messtechnik GmbH
10.1.4 RPE – Probe-Probe Measurement
Not included with:
PC I parameter, Rpe measurement No
PC II (without PE)
PC III
The protective conductor measurement is
conducted while the device under test is
switched off.
The mains connection cable must be moved
around during the protective conductor
measurement, especially at mechanically
stressed points (protection against kinking).
During measurement, the display must be
checked for brief interruptions.
The maximum value is measured and stored
after initially settling in.
Protective conductor resistance is measured
with 200 mA direct current in accordance
with the standard.
All PE parts which are not connected to
each other or are flexibly connected must be
contacted with the probe, one after the
other. During measurement, the maximum
value appears at the lower part of the display
and is used for evaluation.
Connection
➭Connect the first probe to the black GND
socket.
➭Connect the second probe to the red
probe socket.
➭Switch the device under test on.
Procedure
➭Press the RSL key.
➭Select the “Probe-Probe” menu with the
help of the  scroll keys.
➭ Start the measurement by pressing the OK
key.
➭Contact the protective conductor termi-
nal in the DUT’s mains plug with the first
probe.
➭Contact all parts of the DUT which are
connected to PE with the second probe.
➭If the respective measured value is
smaller than the specified limit value, this
is indicated acoustically, OK appears at
the display and the LED lights up
green.
➭You can repeat the measurement by
pressing the scroll key (reset), after
which the LED goes out.

GMC-I Messtechnik GmbH 15
10.1.5 RPE – Balancing the Probe Cable for the
Protective Conductor Measurement
This menu makes it possible to balance the
probe cable’s resistance value.
The maximum offset value, which is sub-
tracted from subsequent measured values,
must not exceed 0.100 .
Connection
➭Connect the probe to the red probe
socket.
Procedure
➭Press the RSL key.
➭Select the “Rsl Balancing” menu with the
help of the  scroll keys.
➭ Start the measurement by pressing the OK
key.
➭Contact one of the test socket’s two
protective conductor terminals.

16 GMC-I Messtechnik GmbH
10.2 RISO – Insulation Resistance
Definition
Protection Category I
Insulation resistance is measured between
short-circuited mains terminals and the pro-
tective conductor.
Protection Categories II and III
Insulation resistance is measured between
short-circuited mains terminals and external
conductive parts which can be contacted
with the probe.
Minimum Permissible Limit Values for Insulation
Resistance per DIN VDE 0701-0702:2008
* With activated heating elements
(where heating power > 3 kW and RISO <0.3M:
leakage current measurement is required)
Note!
All insulation resistance measure-
ments must be performed with the
DUT in the de-energized state.
Observe the following safety instructions for
the connections listed below:
•Probe-PE
• PE grounded via parallel-contact earth-
ing switch
• Probe-Probe , if one side is grounded
Warning: Voltage!
Insulation Resistance Measurement
Testing is conducted with up to
500 V. Current limiting is utilized
(I < 1.0 mA), but if the terminals are
touched, electric shock may occur
which could result in consequential
accidents.
Special Case: Permanently Installed Protection
Class I Devices
Attention!
!
Deactivate the electrical system
which supplies power to the device
under test before connecting the test
instrument!
➭Remove the mains fuses from the device
under test and disconnect neutral con-
ductor N inside the device under test.
➭Connect the probe to phase conductor L
at the device under test in order to mea-
sure insulation resistance.
RISO
PC I PC II PC III Heating
1M2M0.25 M0.3 M*
2M7M
WithPCII

GMC-I Messtechnik GmbH 17
10.2.1 RISO – LN-PE
Note!
All switches at the device under test
must be set to the on position during
measurement of insulation resis-
tance, including temperature con-
trolled switches and temperature reg-
ulators as well.
Measurement must be performed in
all program steps for devices
equipped with program controllers.
Measurement is performed in the de-ener-
gized state.
Connection
➭Insert the test object’s mains plug into
the test socket.
Procedure
➭Press the RISO key.
➭Select the “LN-PE” menu with the help of
the  scroll keys.
➭ Start the measurement by pressing the OK
key.
➭Review the preconfigured parameters for
the heating element (Heat Yes/No) and
for test voltage (250 V/500 V), select
them if necessary using the scroll
keys and adjust them to the momentary
value using the  scroll keys.
➭Wait until the measurement settles in.
➭If the respective measured value is larger
than the specified limit value, OK appears
at the display and the LED lights up
green.
➭You can repeat the measurement by
pressing the scroll key (reset), after
which the LED goes out briefly until
the next measurement is performed.

18 GMC-I Messtechnik GmbH
10.2.2 RISO – LN-Probe
L and N are short-circuited in the test instru-
ment during this measurement and a test
voltage of 500 V (or 250 V with “Surge
Arrester: Yes”) is applied between LN and
PE.
Not Applicable for PC III
This measurement is not performed if there
are no insulated and conductive parts.
Conductive, insulated parts must be con-
tacted one after the other.
Measurement is performed with the DUT in
the de-energized state.
Insulation is measured between LN at the
DUT and accessible, conductive and insu-
lated parts, as well as ELV parts if included.
Connection
➭Insert the test object’s mains plug into
the test socket.
➭Connect the probe to the red probe
socket.
Procedure
➭Press the RISO key.
➭Select the “LN-Probe” menu with the help
of the  scroll keys.
➭ Start the measurement by pressing the OK
key.
➭Contact all insulated, accessible, con-
ductive (and SELV) parts with the probe.
➭If the respective measured value is larger
than the specified limit value, OK appears
at the display and the LED lights up
green.
➭You can repeat the measurement by
pressing the scroll key (reset), after
which the LED goes out briefly until
the next measurement is performed.

GMC-I Messtechnik GmbH 19
10.2.3 RISO – Probe-PE
Insulation Resistance Measurement, Probe
to Conductive Parts (which are connected to
PE)
For PC I Devices with SELV Parts
➭Contact the SELV parts.
Insulation resistance of the SELV parts to PE
is measured with a test voltage of 250 V.
Connection
➭Insert the test object’s mains plug into
the test socket.
➭Connect the probe to the red probe
socket.
Procedure
➭Press the RISO key.
➭Select the “Probe-PE” menu with the help
of the  scroll keys.
➭ Start the measurement by pressing the OK
key.
➭Contact the low-voltage output terminals
with the probe.
➭If the respective measured value is larger
than the specified limit value, OK appears
at the display and the LED lights up
green.
➭You can repeat the measurement by
pressing the scroll key (reset), after
which the LED goes out briefly until
the next measurement is performed.

20 GMC-I Messtechnik GmbH
10.2.4 RISO – Probe-Probe (GND)
Insulation Resistance Measurement, PC III
This measurement is intended exclusively for
protection class III DUTs.
Insulation resistance between two points
(e.g. components) can be determined with
this measurement.
The test voltage and the limit value are
adjustable.
This measurement is not performed if there
are no insulated, conductive parts.
Conductive insulated parts must be con-
tacted one after the other.
Measurement is performed with the DUT in
the de-energized state.
Measurement is conducted with a test volt-
age of 250 or 500 V.
Connection
➭Connect the first probe to the black GND
socket.
➭Connect the second probe to the red
probe socket.
➭Connect phase conductors L1, L2 and
L3 to N and the red probe.
➭Connect PE to the black probe.
Procedure
➭Press the RISO key.
➭Select the “Probe-Probe” menu with the
help of the  scroll keys.
➭ Start the measurement by pressing the OK
key.
➭Review the preconfigured parameters for
the limit value (0.3/1/2 M) and for test
voltage (250 V/500 V), select them if
necessary using the scroll keys and
adjust them to the momentary values
using the  scroll keys.
Heating Elements: “Yes” results in a reduction
of the permissible limit value of 1 Mto
0.3 M.
Test Voltage: In the case of devices with inte-
grated surge arrester, insulation resistance
measurements performed with 500 V may
lead to
“excessively small” measurement results.
Reducing test voltage to 250 V makes it
possible to perform measurement without
activating overvoltage protection.
➭Contact the short-circuited L and N pins
in the DUT’s mains plug with the first
probe.
➭Contact all of the DUT’s insulated, con-
ductive parts with the second probe.
➭If the respective measured value is larger
than the specified limit value, OK appears
at the display and the LED lights up
green.
➭You can repeat the measurement by
pressing the scroll key (reset), after
which the LED goes out briefly until
the next measurement is performed.