Bender ISOMETER isoLR275 User manual

Manual
EN
ISOMETER® isoLR275
Coupling device AGH-LR
Insulation monitoring device for unearthed
IT AC, AC/DC and DC systems
for electrical installations with a low level of resistance
up to AC 793 V/DC 1100 V
Software version: D369 V2.1
isoLR275_D00127_00_M_XXEN/07.2018

Bender GmbH & Co. KG
Londorfer Str. 65 • 35305 Grünberg • Germany
P.O. Box 1161 • 35301 Grünberg • Germany
Tel.: [phone]
Fax: [phone]
E-mail: [email protected]
Web: http://www.bender.de
© Bender GmbH & Co. KG
All rights reserved.
Reprinting only with permission
of the publisher.
Subject to change!
Photos: Bender archive and bendersystembau archive.

3
Table of Contents
isoLR275_D00127_00_M_XXEN/07.2018
1. Safety instructions .................................................................................. 6
1.1 Intended use ............................................................................................................. 6
1.1.1 Personnel .................................................................................................................... 6
1.1.2 Hazards when handling the ISOMETER® isoLR275 ...................................... 6
1.1.3 Note .............................................................................................................................. 7
1.2 Explanation of symbols and notes .................................................................... 8
1.3 Directions for installation ..................................................................................... 9
2. Function ................................................................................................. 11
2.1 Device features isoLR275 .................................................................................... 11
2.2 Device features AGH-LR ...................................................................................... 12
2.3 Product description .............................................................................................. 12
2.4 Description of function ....................................................................................... 13
2.4.1 Measurement profiles .......................................................................................... 14
2.4.2 Self test ...................................................................................................................... 15
2.4.3 Current output for external measuring instrument .................................. 16
2.4.4 Real-time clock ....................................................................................................... 17
2.4.5 Coupled IT systems ............................................................................................... 17
2.4.6 Function input F1/F2 for connection or disconnection of
IT systems being monitored .............................................................................. 18
2.4.7 ISOnet function (COM SETUP) ........................................................................... 20
3. Commissioning flow chart (in three parts) ...................................... 22
4. Installation and connection ............................................................... 26
4.1 Mounting of the isoLR275 .................................................................................. 26
4.2 Wiring diagram ....................................................................................................... 26

Table of Contents
4isoLR275_D00127_00_M_XXEN/07.2018
5. Operation and configuration .............................................................. 30
5.1 Display and operating elements ...................................................................... 30
5.1.1 Display in standard mode ................................................................................... 31
5.1.2 Display in menu mode ......................................................................................... 32
5.1.3 Control buttons ...................................................................................................... 32
5.2 Menu structure and menu mode ..................................................................... 34
5.2.1 Navigation within the menu .............................................................................. 34
5.2.2 Parameter change ................................................................................................. 34
5.2.3 Changing from the menu mode to the standard mode ......................... 35
5.2.4 Diagram menu structure ..................................................................................... 36
5.3 Menu HISTORY INFO ............................................................................................. 37
5.3.1 Diagram HISTORY INFO ....................................................................................... 38
5.4 Menu ISO SETUP: Setting of the basic
ISOMETER® functions ........................................................................................... 39
5.4.1 Response values Alarm1 and Alarm2 ............................................................. 39
5.4.2 Operating principle of the alarm relays ......................................................... 39
5.4.3 Memory setting (on/off) ...................................................................................... 42
5.4.4 Current output for external measuring instruments ................................ 42
5.4.5 Adjusting the current output to the centre scale mark of
external measuring instruments ...................................................................... 42
5.5 Menu ISO ADVANCED: Setting of the extended
functions ................................................................................................................... 44
5.5.1 External coupling device (AGH: LR) ................................................................. 44
5.5.2 Adaptation of the system leakage capacitance
(Cemax: 150 µF) ...................................................................................................... 44
5.5.3 Changing the measurement method (Measure: AMP4) ......................... 44
5.5.4 Setting the repetition time for the automatic self test
(Autotest: 24h) ........................................................................................................ 47
5.5.5 Setting the real-time clock (Clock) .................................................................. 47
5.5.6 Setting the date (Date) ........................................................................................ 47
5.5.7 Specifying the start-up time for the automatic self test (Test) .............. 47
5.5.8 Diagram ISO ADVANCED .................................................................................... 48
5.6 Menu COM SETUP: Setting the BMS interface ............................................ 49
5.6.1 Bus address "Addr:" ............................................................................................... 49

Table of Contents
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isoLR275_D00127_00_M_XXEN/07.2018
5.6.2 ISOnet function ...................................................................................................... 49
5.6.3 ISO monitor .............................................................................................................. 50
5.6.4 Diagram COM SETUP ............................................................................................ 51
5.7 PASSWORD menu ................................................................................................. 52
5.7.1 Setting and activating the password ............................................................. 52
5.7.2 PASSWORD diagram ............................................................................................ 53
5.8 LANGUAGE Menu .................................................................................................. 54
5.8.1 Language setting ................................................................................................... 54
5.8.2 Language diagram ................................................................................................ 55
5.9 SERVICE menu ......................................................................................................... 55
6. Serial interface ...................................................................................... 56
6.1 RS-485 interface with BMS protocol ............................................................... 56
6.2 Topology RS-485 network .................................................................................. 57
6.2.1 Correct arrangement ............................................................................................ 57
6.2.2 Wrong arrangement ............................................................................................. 57
6.2.3 Wiring ......................................................................................................................... 57
6.3 BMS protocol ........................................................................................................... 58
6.3.1 BMS master .............................................................................................................. 59
6.3.2 BMS slave ..................................................................................................................60
6.3.3 Commissioning of an RS-485 network with BMS protocol .................... 61
7. Technical data isoLR275 with AGH-LR ............................................. 63
7.1 isoLR275 data in tabular form ........................................................................... 63
7.2 AGH-LR data in tabular form ............................................................................. 67
7.3 Standards, approvals and certifications ........................................................ 68
7.4 Characteristic curves ............................................................................................ 69
7.5 Ordering information ........................................................................................... 74
7.6 Label for modified versions ............................................................................... 75
INDEX ........................................................................................................... 76

6isoLR275_D00127_00_M_XXEN/07.2018
1. Safety instructions
1.1 Intended use
The ISOMETER® is intended for:
 Monitoring the insulation resistance of IT systems
Use which deviates from or is beyond the scope of these technical specifica-
tions is considered non-compliant. The Bender companies shall not be liable
for any losses or damage arising therefrom.
Intended use also implies:
 Compliance with all information in this operating manual and
 Compliance with any test intervals.
1.1.1 Personnel
Only appropriately qualified personnel may work on the ISOMETER®. Qualified
means familiar with the installation, commissioning and operation of the pro-
duct and with training appropriate to the work. Personnel must have read and
understood the safety section and warning information in this operating
manual.
1.1.2 Hazards when handling the ISOMETER® isoLR275
The ISOMETER® is constructed according to the state-of-the-art and the recog-
nised technical safety rules. Nevertheless, when it is being used, hazards may
occur to the life and limb of the user or third parties or there may be adverse
effects on the ISOMETER® or on other valuable property. Only use the
ISOMETER®:
 As intended
 In perfect working order
Any faults which may impair safety must be eliminated immediately. Imper-
missible modifications and the use of spare parts and additional devices
which are not sold and recommended by the manufacturer of the devices
may cause fires, electric shocks and injuries.

Safety instructions
7
isoLR275_D00127_00_M_XXEN/07.2018
Unauthorised persons must not have access to or contact with the ISOME-
TER®.
Information plates must always be clearly legible.
Damaged or illegible signs must be replaced immediately.
1.1.3 Note
Make sure that the operating voltage is correct!
Prior to insulation and voltage tests, the ISOMETER® must be disconnected
from the power system for the duration of the test.
In order to check the proper connection of the device, it is recommended to
carry out a functional test.
Make sure that the basic settings meet the requirements of the IT system.
Children and unauthorised persons must not have access to or contact with
the ISOMETER®.

Safety instructions
8isoLR275_D00127_00_M_XXEN/07.2018
1.2 Explanation of symbols and notes
To make it easier for you to understand and revisit certain sections of text and
instructions in this manual, we have used symbols to identify important inst-
ructions and information. The meaning of these symbols is explained below:
This signal word indicates that there is a high risk of danger
that will result in electrocution or serious injury if not
avoided.
This signal word indicates a medium risk of danger that can
lead to
death or serious injury if not avoided.
This signal word indicates a low-level risk that can result in
minor or moderate injury or damage to property if not
avoided.
This symbol denotes information intended to assist the user in
making
optimum use of the product.
DANGER
WARNING
CAUTION

Safety instructions
9
isoLR275_D00127_00_M_XXEN/07.2018
1.3 Directions for installation
The terminals and KE have to be connected by a separate wire to the pro-
tective conductor (PE). If the terminals L1, L2 of the device are connected to
an IT system under operation, the terminals and KE must not be discon-
nected from the protective conductor (PE).
In order to check the proper connection of the device, it is recommended to
carry out a functional test using an insulation fault, e.g. via a suitable resis-
tance, before starting the ISOMETER®.
Risk of property damage due to unprofessional
installation!
If more than one insulation monitoring device is connected
to aconductively connected system, the system can be da-
maged. If several devices are connected, the device does not
function and does not signal insulation faults. Make sure
that only one insulation monitoring device is connected in
each conductively connected system.
Ensure disconnection from the IT system!
When insulation or voltage tests are to be carried out, the de-
vice must be isolated from the system for the test period. Other-
wise, the device may be damaged.
CAUTION
CAUTION

Safety instructions
10 isoLR275_D00127_00_M_XXEN/07.2018
The device variant -3… is delivered with the following factory set-
ting:
Please check if the factory setting of the ISOMETER® complies with the requi-
rements of the IT system to be monitored.
Response value Ran
For correct setting of the response value in kΩ, it is useful to know the present
value of the insulation resistance of the electrical installation.
ISO SETUP: Alarm 1/Alarm 2
(response values)
= 4 kΩ/1 kΩ
ISO SETUP: Operating mode K1/K2 = N/O operation
(N.O.)
ISO SETUP: Memory = off
ISO ADVANCED: System leakage capacitance
Measurement method
=
=
150 µF
AMP
COM SETUP: Bus address = 3 (Slave)
When the AC system being monitored contains galvanically
coupled DC circuits:
An insulation fault can only be monitored correctly when the
rectifiers carry a continuous load current of 5…10 mA.

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isoLR275_D00127_00_M_XXEN/07.2018
2. Function
2.1 Device features isoLR275
 ISOMETER® for IT AC systems with galvanically connected rectifiers or
converters
 and for IT DC systems (IT = unearthed systems)
 Particularly suited for monitoring electrical installations with a low level
of resistance
 isoLR275 is always operated in conjunction with AGH-LR
 Automatic adaptation to the existing system leakage capacitance
 -Measurement method (European Patent: EP 0 654 673 B1)
 Choice of measurement methods to meet different requirements
 Two separately adjustable response ranges of 0.2 kΩ…100 kΩ each
(Alarm 1, Alarm 2)
 Two-line LC display
 Automatic device self test
 Memory with real-time clock to store alarm messages with date and
time stamp
 BMS interface (Bender Measuring Device Interface) for communication
with other Bender devices (RS-485 galvanically isolated)
 Internal disconnection of the ISOMETER® from the IT system to be
monitored (via control signal; terminals F1/F2), e.g. if several
ISOMETER®s are interconnected
 Current output 0(4)…20 mA (electrically isolated) in relation to the
insulation value measured in the system
AMPPlus

Function
12 isoLR275_D00127_00_M_XXEN/07.2018
2.2 Device features AGH-LR
 Coupling device required for ISOMETER® isoLR275,
 each AGH-LR is specially adapted to the corresponding isoLR275
 Nominal voltage range AC 0…793 V and DC 0…1,100 V
 DIN rail mounting
2.3 Product description
The isoLR275 ISOMETER® in conjunction with the AGH-LR coupling device
monitors the insulation resistance of IT systems. It is suitable for universal use
in 3(N)AC, AC/DC and DC systems. AC systems may include extensive DC-sup-
plied loads, such as converters or thyristor-controlled DC drives. The adapta-
tion to the existing system leakage capacitances takes place automatically.
Only use the AGH-LR coupling device supplied with the device for adaptation
of the nominal voltage range.
isoLR275 can share the BMS bus with other bus devices.
The devices isoLR275 and AGH-LR are ideally adapted to each
other. The corresponding combination device required in each
case can be identified via the serial number on the device label.
For repair work, both devices should be sent in in order to gua-
rantee measuring accuracy.
Otherwise, the measuring accuracy might be reduced!

Function
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isoLR275_D00127_00_M_XXEN/07.2018
2.4 Description of function
The isoLR275 ISOMETER® is connected between the unearthed system (IT sys-
tem) and the protective conductor (PE) using the AGH-LR coupling device.
The response values and other function parameters are set via the function
buttons. The parameters are indicated on the LC display and are stored in a
non-volatile memory (EEPROM).
A microprocessor-controlled pulsating AC measuring voltage is superimpo-
sed on the IT system to be monitored ( measurement method*).
The measuring pulse consists of positive and negative cycles of the same am-
plitude. The period depends on the respective system leakage capacitances
and the insulation resistance of the system to be monitored.
An insulation fault between system and earth closes the measuring circuit.
The evaluation circuit calculates the insulation resistance which is indicated
on the LC display or the external kW measuring instrument after the measu-
ring time has expired.
The measuring time is dependent on the selected measurement method, the
system leakage capacitance, the insulation resistance and the system-related
disturbances.
System leakage capacitances do not influence the measuring accuracy.
If the reading is below the selected response values Alarm 1/Alarm 2, the as-
sociated alarm relays respond, the LEDs "Alarm 1/2“ light up and the measu-
ring value is indicated on the LC display (in the event of DC insulation faults,
the faulty supply line is indicated). If the terminals R1/R2 are bridged (external
reset button [N/C contact] or wire jumper), the fault message will be stored.
Pressing the reset button, resets the fault message, provided that the insulati-
on resistance is at least 25 % and at least 1 kW above the actual response va-
lue. The fault memory behaviour can also be set in the "ISO SETUP“ menu, by
selecting the submenu Memory: on/off.
*) measurement method
(Adaptive Measuring Pulse), a measurement method developed by Bender
(European Patent: EP 0 654 673 B1).
AMP
Plus
AMPPlus
AMP
Plus
AMPPlus

Function
14 isoLR275_D00127_00_M_XXEN/07.2018
2.4.1 Measurement profiles
The measuring circuit of the isoLR275 can be adjusted to different require-
ments in the ISO ADVANCED/MEASURE menu:
DC = Suitable for pure AC systems
AMP = Suitable for converters with frequencies > 10 Hz
AMP2 = Suitable for converters with frequencies < 10 Hz
AMP3 = Suitable for converters with frequencies < 1 Hz
AMP4 = Suitable for installations with strongly varying DC components
Also refer to the table of measurement profiles starting from page 44.

Function
15
isoLR275_D00127_00_M_XXEN/07.2018
2.4.2 Self test
A self test can be started automatically or manually by means of the test but-
ton. In order to guarantee high functional reliability, the ISOMETER® provides
comprehensive self test functions. After switching the device to the supply
voltage, all internal measuring functions, the components of the process con-
trol such as data and parameter memory as well as system and earth connec-
tions are checked using the self test functions. The progress of the self test is
shown on the display by a bar graph. Depending on the IT system conditions,
the self test is completed after 15…20 seconds, then the message "Test ok!“
appears on the display for approximately two seconds. Then the device re-
turns to the normal measuring mode and the currently measured value will be
displayed once the measuring time has elapsed.
When a device or connection fault is found, the message "!Error!“ appears on
the display, the device error LED lights, the relay K2 (21-22-24) switches and
the corresponding fault message (see table) will be indicated. If such a device
error occurs, another self test is started after approximately one minute. If no
more faults are detected, the fault message will automatically be deleted, the
system fault LED will go out.
During operation, the self test function can be started by pressing the test
button (internal or external). The self test can also be started automatically
every hour or every 24 hours by selecting the "ISO ADVANCED: Autotest:“ me-
nu.
The alarm relays 1/2 only switch after starting the self test function by pressing
the test button, that means, in case of an automatic self test the relays do not
switch.

Function
16 isoLR275_D00127_00_M_XXEN/07.2018
2.4.3 Current output for external measuring instrument
The current output of isoLR275 is electrically isolated from the device electro-
nics and the RS-485 interface.
An output current range of 0…20 mA or 4…20 mA can be selected by means
of the ISO SETUP menu, refer to page 36. In addition, the centre scale mark can
be set to 28 kΩ or 120 kΩ, related to an external measuring instrument.
Alarm
message Description Actions
Connection
PE?
No low-resistance
connection bet-
ween the terminals
and KE to
earth (PE).
1. Check the wiring of the terminals
and KE to earth (PE)
2. Press the "TEST" button
3. Switch the supply voltage on and off
Device error
x
Internal device
error
1. Press the "TEST" button
2. Switch the supply voltage off and on
3. Please contact Bender
If, for functional reasons, the supply voltage cannot be
switched on or off, a reset of the sequence control system can
be carried out by pressing the buttons "ESC", "RESET" and
"MENU“ simultaneously.

Function
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isoLR275_D00127_00_M_XXEN/07.2018
2.4.4 Real-time clock
The real-time clock serves as a time base for the memory and self test func-
tions. First, the correct time and date must be set in the "ISO ADVANCED“ me-
nu. If time and date are not set, a "C“ (clock) is flashing in the standard display.
In the event of a supply voltage failure, time and date will be stored for at least
30 days.
When the 24 h self test is activated in the ISO ADVANCED menu, it is possible
to set the time (hour) for carrying out the self test by means of the
"TEST: 12:00" menu. Then a self test will be started automatically once a day
exactly at the preset time. If the 1 h test has been selected, the self test is au-
tomatically carried out every full hour.
2.4.5 Coupled IT systems
When using ISOMETER®s in IT systems, make sure that only one active
ISOMETER® is connected in each interconnected system. If IT systems are in-
terconnected via coupling switches, make sure that ISOMETER®s not currently
used are disconnected from the IT system and deactivated. IT systems coup-
led via diodes or capacitances may also influence the insulation monitoring
process so that a central control of the different ISOMETER®s is required.

Function
18 isoLR275_D00127_00_M_XXEN/07.2018
2.4.6 Function input F1/F2 for connection or disconnection of IT
systems being monitored
The ISOMETER® can be disconnected from the IT system and set to STANDBY
mode with the function input F1/F2. If the input F1/F2 is bridged, the connec-
tions to the coupling device AK1/AK2 are switched off via internal coupling re-
lays, the measuring function is stopped and the message "STANDBY" appears
on the display. Instead of the most recently measured value the value > 1 MΩ
will be indicated. Furthermore, the alarm relays and alarm LEDs stop signal-
ling alarm messages.
After opening the function input F1/F2, the connection to the IT system will
be restored and a completely new insulation resistance measurement cycle is
started.
This function can be used to disconnect an isoLR275 selectively in IT systems
via the auxiliary contacts of the respective coupling switch. One coupling
switch each in a line-type or ring-type arrangement can deactivate a subse-
quent isoLR275 to ensure that only one ISOMETER® is active in each galvani-
cally connected IT system.
If in a ring-type arrangement all coupling switches are closed, theoretically all
ISOMETER®s would be deactivated. In order to prevent this, a BMS master
(BMS addr. 1) monitors the condition of the function input F1/F2 of all slave
ISOMETER®s. When all slave ISOMETER®s are in the STANDBY mode, the insu-
lation monitoring function of the master ISOMETER® and hence the function
input F1/F2 of the master are without function in this mode. Details are illust-
rated in the graphic below:

Function
19
isoLR275_D00127_00_M_XXEN/07.2018
isoLR275
AGH-LR isoLR275
AGH-LR
isoLR275
AGH-LR isoLR275
AGH-LR
BMS bus
ss
ss
Addr. Addr.
Addr. Addr.
RS-485)

Function
20 isoLR275_D00127_00_M_XXEN/07.2018
2.4.7 ISOnet function (COM SETUP)
To activate this function, select "ISOnet=ON“ in the COM SETUP menu. This
function is a type of scanning function. The BMS master with activated ISOnet
function controls the ISOnet slave devices via the BMS bus. When the master
ISOMETER® has finished one measuring cycle, the authorisation for insulation
monitoring is passed on to the next higher BMS address. During the insulation
monitoring process, all other ISOMETER®s are in the STANDBY mode. In this
way it is prevented that ISOMETER®s influence each other in interconnected IT
systems. In comparison to a solution with coupling switches and function in-
put F1/F2, the response time will be extended because the measurement is
not permanently carried out. This has the advantage that no auxiliary contacts
of a coupling switch are required. Furthermore, this solution is recommended
for IT systems coupled via capacitances or diodes.
Each ISOnet slave checks the network for an ISOnet master. If no master exists,
the fault "ISOnet Master?" will be output on the display. With the ISOnet func-
tion activated, the function input F1/F2 is automatically deactivated.