Bender ISOMETER isoPV with AGH-PV User manual

Manual
EN
isoPV_D00024_02_M_XXEN/07.2018
ISOMETER® isoPV
coupling device AGH-PV
Insulation monitoring device for unearthed
IT AC, AC/DC and DC systems
for photovoltaic systems up to AC 793 V/DC 1100 V
Software version: D351 V2.0

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

3
Table of Contents
isoPV_D00024_02_M_XXEN/07.2018
1. Important information ........................................................................... 7
1.1 How to use this manual ......................................................................................... 7
1.2 Technical support: service and support .......................................................... 8
1.2.1 First level support .................................................................................................... 8
1.2.2 Repair service ............................................................................................................ 8
1.2.3 Field service ............................................................................................................... 9
1.3 Training courses ....................................................................................................... 9
1.4 Delivery conditions ................................................................................................. 9
1.5 Inspection, transport and storage ..................................................................... 9
1.6 Warranty and liability ........................................................................................... 10
1.7 Disposal .....................................................................................................................10
2. Safety instructions ............................................................................... 11
2.1 General safety instructions ................................................................................ 11
2.2 Work activities on electrical installations ...................................................... 11
2.3 Intended use ........................................................................................................... 11
2.3.1 Personnel ..................................................................................................................12
2.3.2 Hazards when handling the ISOMETER® isoPV ........................................... 12
2.3.3 Note ............................................................................................................................ 12
2.4 Directions for installation ................................................................................... 13
3. Function ................................................................................................. 15
3.1 Features isoPV ......................................................................................................... 15
3.2 Features AGH-PV .................................................................................................... 15
3.3 Application ............................................................................................................... 16
3.4 Description of function ....................................................................................... 16
3.4.1 Measurement profiles .......................................................................................... 17
3.4.2 Self test ...................................................................................................................... 17
3.4.3 Current output for external measuring instrument .................................. 18

Table of Contents
4isoPV_D00024_02_M_XXEN/07.2018
3.4.4 Real-time clock ....................................................................................................... 19
3.4.5 Coupled IT systems ............................................................................................... 19
3.4.6 Function input F1/F2 for connection or disconnection of
IT systems being monitored ............................................................................. 19
3.4.7 ISOnet function (COM SETUP) ........................................................................... 21
4. Commissioning flow chart (threepart) .............................................. 22
5. Installation and connection ................................................................ 25
5.1 Installation of the isoPV ....................................................................................... 26
5.2 Wiring diagram ....................................................................................................... 27
6. Operation and setting .......................................................................... 30
6.1 Display and operating elements ...................................................................... 30
6.1.1 Display in standard mode ................................................................................... 31
6.1.2 Display in menu mode ......................................................................................... 31
6.1.3 Function buttons ................................................................................................... 31
6.2 Menu structure and menu mode ..................................................................... 34
6.2.1 Navigation within the menu .............................................................................. 34
6.2.2 Parameter change ................................................................................................. 34
6.2.3 Changing from the menu mode to the standard mode ......................... 34
6.2.4 Diagram menu structure ..................................................................................... 35
6.3 Menu HISTORY INFO ............................................................................................. 36
6.3.1 Diagram HISTORY INFO ....................................................................................... 37
6.4 Menu ISO SETUP: Setting of the basic ISOMETER functions .................. 38
6.4.1 Response values Alarm1 and Alarm2 ............................................................. 38
6.4.2 Operating principle of the alarm relays ......................................................... 39
6.4.3 Memory setting (on/off) ...................................................................................... 41
6.4.4 Current output for external measuring instruments ................................ 41
6.4.5 Matching the current output to the centre scale mark of
external measuring instruments ...................................................................... 41
6.5 Menu ISO ADVANCED: Setting of the extended functions .................... 42
6.5.1 External coupling device (AGH: PV) ................................................................ 42
6.5.2 Adaptation of the system leakage capacitance (Cemax: 2000 μF) ..... 42
6.5.3 Changing the measurement method (Measure: AMP4) ......................... 42

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isoPV_D00024_02_M_XXEN/07.2018
6.5.4 Setting the repetition time for the automatic self test
(Autotest: 24h) ........................................................................................................ 43
6.5.5 Setting the real-time clock (Clock) .................................................................. 44
6.5.6 Setting the date (Date) ........................................................................................ 44
6.5.7 Specifying the start-up time for the automatic self test (Test) ............. 44
6.5.8 Diagram ISO ADVANCED .................................................................................... 45
6.6 Menu COM SETUP: Setting the BMS interface ............................................ 46
6.6.1 Bus address "Addr:" ............................................................................................... 46
6.6.2 ISOnet function ...................................................................................................... 46
6.6.3 ISO monitor .............................................................................................................. 46
6.6.4 Diagram COM SETUP ............................................................................................ 47
6.7 PASSWORD menu ................................................................................................. 48
6.7.1 Setting and activating the password ............................................................. 48
6.7.2 PASSWORD diagram ............................................................................................ 48
6.8 LANGUAGE Menu ................................................................................................. 49
6.8.1 Language setting ................................................................................................... 49
6.8.2 Language diagram ................................................................................................ 49
6.9 SERVICE menu ......................................................................................................... 49
7. Serial interface ...................................................................................... 50
7.1 RS-485 interface with BMS protocol ............................................................... 50
7.2 Topology RS-485 network .................................................................................. 50
7.2.1 Correct arrangement ............................................................................................ 51
7.2.2 Wrong arrangement ............................................................................................. 51
7.2.3 Wiring ......................................................................................................................... 51
7.3 BMS protocol ........................................................................................................... 52
7.3.1 BMS master .............................................................................................................. 52
7.3.2 BMS slave ..................................................................................................................53
7.3.3 Commissioning of an RS-485 network with BMS protocol .................... 54
8. Coupled PV generators (application example) .............................. 56

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6isoPV_D00024_02_M_XXEN/07.2018
9. Technical data isoPV with AGH-PV .................................................... 59
9.1 Data in tabular form isoPV .................................................................................. 59
9.2 Technical data in tabular form AGH-PV ......................................................... 62
9.3 Standards, approvals and certifications ........................................................ 63
9.4 Characteristic curves ............................................................................................ 64
9.5 Ordering information ........................................................................................... 68

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isoPV_D00024_02_M_XXEN/07.2018
1. Important information
1.1 How to use this manual
To make it easier for you to understand and revisit certain sections in this manual, we
have used symbols to identify important instructions and information. The meaning of
these symbols is explained below:
This manual is intended for qualified personnel working in electrical
engineering and electronics!
Pleas read this manual before mounting, connecting and commissioning
the device. Always keep this manual within easy reach for future reference.
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 medium risk of danger that can lead to
death or serious injury if not avoided.
This symbol denotes information intended to assist the user in making
optimum use of the product.
DANGER
WARNING
CAUTION

Important information
8isoPV_D00024_02_M_XXEN/07.2018
1.2 Technical support: service and support
For commissioning and troubleshooting Bender offers you:
1.2.1 First level support
Technical support by phone or e-mail for all Bender products
• Questions concerning specific customer applications
• Commissioning
• Troubleshooting
Telephone: [phone]*
Fax: [phone]
E-mail: [email protected]
1.2.2 Repair service
Repair, calibration, update and replacement service for Bender products
• Repairing, calibrating, testing and analysing Bender products
• Hardware and software update for Bender devices
• Delivery of replacement devices in the event of faulty or incorrectly delivered
Bender devices
• Extended guarantee for Bender devices, which includes an in-house repair service
or replacement devices at no extra cost
Telephone: [phone]** (technical issues)
[phone]**, -785** (sales)
Fax: [phone]
E-mail: [email protected]
Please send the devices for repair to the following address:
Bender GmbH, Repair-Service,
Londorfer Str. 65,
35305 Grünberg

Important information
9
isoPV_D00024_02_M_XXEN/07.2018
1.2.3 Field service
On-site service for all Bender products
• Commissioning, configuring, maintenance, troubleshooting of Bender products
• Analysis of the electrical installation in the building (power quality test, EMC test,
thermography)
• Training courses for customers
Telephone: [phone]**, -762 **(technical issues)
[phone]** (sales)
Fax: [phone]
E-mail: [email protected]
Internet: www.bender-de.com
* Available from 7.00 a.m. to 8.00 p.m. 365 days a year (CET/UTC+1)
** Mo-Thu 7.00 a.m. - 8.00 p.m., Fr 7.00 a.m. - 13.00 p.m
1.3 Training courses
Bender is happy to provide training regarding the use of test equipment.
The dates of training courses and workshops can be found on the Internet at
www.bender-de.com -> Know-how -> Seminars.
1.4 Delivery conditions
Bender sale and delivery conditions apply.
For software products the "Softwareklausel zur Überlassung von Standard-Software als
Teil von Lieferungen, Ergänzung und Änderung der Allgemeinen Lieferbedingungen
für Erzeugnisse und Leistungen der Elektroindustrie" (software clause in respect of the
licensing of standard software as part of deliveries, modifications and changes to gene-
ral delivery conditions for products and services in the electrical industry) set out by the
ZVEI (Zentralverband Elektrotechnik- und Elektronikindustrie e. V.) (German Electrical
and Electronic Manufacturer's Association) also applies.
Sale and delivery conditions can be obtained from Bender in printed or electronic for-
mat.
1.5 Inspection, transport and storage
Inspect the dispatch and equipment packaging for damage, and compare the contents
of the package with the delivery documents. In the event of damage in transit, please
contact Bender immediately. The devices must only be stored in areas where they are
protected from dust, damp, and spray and dripping water, and in which the specified
storage temperatures can be ensured.

Important information
10 isoPV_D00024_02_M_XXEN/07.2018
1.6 Warranty and liability
Warranty and liability claims in the event of injury to persons or damage to property are
excluded if they can be attributed to one or more of the following causes:
• Improper use of the device.
• Incorrect mounting, commissioning, operation and maintenance of the device.
• Failure to observe the instructions in this operating manual regarding transport,
commissioning, operation and maintenance of the device.
• Unauthorised changes to the device made by parties other than the manufactu-
rer.
• Non-observance of technical data.
• Repairs carried out incorrectly and the use of replacement parts or accessories not
approved by the manufacturer.
• Catastrophes caused by external influences and force majeure.
• Mounting and installation with device combinations not recommended by the
manufacturer.
This operating manual, especially the safety instructions, must be observed by all per-
sonnel working on the device. Furthermore, the rules and regulations that apply for ac-
cident prevention at the place of use must be observed.
1.7 Disposal
Abide by the national regulations and laws governing the disposal of this device. Ask
your supplier if you are not sure how to dispose of the old equipment.
The directive on waste electrical and electronic equipment (WEEE directive) and the di-
rective on the restriction of certain hazardous substances in electrical and electronic
equipment (RoHS directive) apply in the European Community. In Germany, these poli-
cies are implemented through the "Electrical and Electronic Equipment Act" (ElektroG).
According to this, the following applies:
• Electrical and electronic equipment are not part of household waste.
• Batteries and accumulators are not part of household waste and must be dispo-
sed of in accordance with the regulations.
• Old electrical and electronic equipment from users other than private households
which was introduced to the market after 13 August 2005 must be taken back by
the manufacturer and disposed of properly.
For more information on the disposal of Bender devices, refer to our homepage at
www.bender-de.com -> Service & support.

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isoPV_D00024_02_M_XXEN/07.2018
2. Safety instructions
2.1 General safety instructions
Part of the device documentation in addition to this manual is the enclosed "Safety in-
structions for Bender products".
2.2 Work activities on electrical installations
If the device is used outside the Federal Republic of Germany, the applicable local stan-
dards and regulations must be complied with. The European standard EN 50110 can be
used as a guide.
2.3 Intended use
The ISOMETER®is intended for:
• monitoring the insulation resistance of IT systems
Use which deviates from or is beyond the scope of the intended use 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
Only qualified personnel are permitted to carry out the work necessary to
install, commission and run a device or system.
Risk of electrocution due to electric shock!
Touching live parts of the system carries the risk of:
• An electric shock
• Damage to the electrical installation
• Destruction of the device
Before installing and connecting the device, make sure that the
installation has been de-energised. Observe the rules for working on
electrical installations.
DANGER

Safety instructions
12 isoPV_D00024_02_M_XXEN/07.2018
2.3.1 Personnel
Only appropriately qualified personnel may work on the ISOMETER®. Qualified means
familiar with the installation, commissioning and operation of the product and with
training appropriate to the work. Personnel must have read and understood the safety
section and warning information in this operating manual.
2.3.2 Hazards when handling the ISOMETER® isoPV
The ISOMETER® is constructed according to the state-of-the-art and the recognised
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®:
• within the scope of its intended use
• in perfect working order
Any faults which may impair safety must be eliminated immediately. Impermissible mo-
difications and the use of spare parts and additional devices which are not sold and re-
commended by the manufacturer of the devices may cause fires, electric shocks and
injuries.
Unauthorised persons must not have access to or contact with the ISOMETER®.
Warning signs must always be easily legible.
Damaged or illegible signs must be replaced immediately.
In order to meet the requirements of the applicable standards, customised parameter
settings must be made on the equipment in order to adapt it to local equipment and
operating conditions. Please heed the limits of the range of application indicated in the
technical data.
Any use other than that described in this manual is regarded as improper.
2.3.3 Note
Make sure that the operating voltage is correct!
Prior to insulation and voltage tests, the ISOMETER®must be disconnected from the po-
wer system for the duration of these tests.
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
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isoPV_D00024_02_M_XXEN/07.2018
2.4 Directions for installation
The terminals and KE have to be connected by a separate wire to the protective con-
ductor (PE). If the terminals L1, L2 of the device are connected to an IT system under
operation, the terminals and KE must not be disconnected from the protective con-
ductor (PE).
In order to check the proper connection of the device, it is recommended to carry out a
functional test using a genuine insulation fault RF, e.g. via a suitable resistance, before
starting the ISOMETER.
The device variant -3.. is delivered with the following factory setting:
Please check if the basic setting of the ISOMETER® complies with the requirements 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 photovoltaic system.
Subject to the IEC 62109-2 standard, a drop in insulation resistance at the input of the
photovoltaic inverter below a specified minimum value is not permitted. This resistance
is dependent on the performance range of the photovoltaic system.
Only one insulation monitoring device may be used in each
interconnected IT system.
When insulation or voltage tests are to be carried out, the device shall be
isolated from the system for the test period..
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
=
=
2,000 μF
AMP4
COM SETUP: Bus address = 3 (slave)

Safety instructions
14 isoPV_D00024_02_M_XXEN/07.2018
For systems ≤ 30 kVA it is imperative that:
the insulation resistance between the inverter input and the earth is at least 500 kΩ. For
mains voltages greater than 500 V the formula below applies:
For systems > 30 kVA the following formula applies:
VmaxPV = Maximum value of the photovoltaic system voltage
Pmax = Maximum value of the active power of the photovoltaic system
When an 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.
R1kΩ
V
------------V•maxPV
=
R5000V VmaxPV
•
Pmax
---------------------------------------------
=

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isoPV_D00024_02_M_XXEN/07.2018
3. Function
3.1 Features isoPV
• ISOMETER® for IT AC systems with galvanically connected
rectifiers or converters
and for IT DC systems (IT = unearthed systems)
• Particularly suitable for monitoring photovoltaic systems
• isoPV is always operated in combination with the coupling device AGH-PV
• 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® (via control signal; terminals
F1/F2) from the IT system to be monitored (e.g. if several ISOMETER®s
are interconnected)
• Current output 0(4)…20 mA (electrically isolated) in relation to the measured
insulation value
3.2 Features AGH-PV
• Coupling device required for ISOMETER® isoPV,
each AGH-PV is specially designed for the corresponding isoPV
• Nominal voltage range AC 0…793 V and DC 0…1,100 V
• DIN rail mounting
AMPPlus

Function
16 isoPV_D00024_02_M_XXEN/07.2018
3.3 Application
The ISOMETER®type isoPV in combination with the AGH-PV 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-supplied loads, such as conver-
ters or thyristor-controlled DC drives. The adaptation to the existing system leakage ca-
pacitances takes place automatically.
Only use the AGH-PV coupling device supplied with the device for adaptation of the no-
minal voltage range.
isoPV can share the BMS bus with other bus devices.
3.4 Description of function
The ISOMETER®isoPV is connected between the unearthed system (IT system) and the
protective conductor (PE) using the coupling device AGH-PV.
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 superimposed on the
IT system to be monitored ( -measurement method*).
The measuring pulse consists of positive and negative cycles of the same amplitude.
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 evalua-
tion circuit calculates the insulation resistance which is indicated on the LC display or
the external kW measuring instrument after the measuring 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.
The two devices isoPV and AGH-PV 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 guarantee
measuring accuracy.
Otherwise, the measuring accuracy might be reduced!
AMPPlus
AMPPlus

Function
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isoPV_D00024_02_M_XXEN/07.2018
If the reading is below the selected response values Alarm 1/Alarm 2, the associated
alarm relays respond, the LEDs "Alarm 1/2“ light up and the measuring value is indica-
ted on the LC display (in the event of DC insulation faults, the faulty supply line is indi-
cated). 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 insulation resistance is at least above 25 % and at least 1 kΩ
above the actual response value. 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).
3.4.1 Measurement profiles
The measuring circuit of isoPV can be adjusted in the ISO ADVANCED/MEASURE menu
to match different requirements:
DC = Suitable for pure AC systems
AMP = Suitable for converters with frequencies > 10Hz
AMP2 = Suitable for converters with frequencies < 10Hz
AMP3 = Suitable for photovoltaic plants with crystalline cells
AMP4 = Suitable for photovoltaic plants with thin-layer cells
Also refer to the measurement methods table starting from Page 42.
3.4.2 Self test
A self test can be started automatically or manually by means of the test button. 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 control, such as data and parameter memory
as well as system and earth connections, 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 sys-
tem 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 returns 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 dis-
play, 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
will be 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.
AMPPlus
AMPPlus

Function
18 isoPV_D00024_02_M_XXEN/07.2018
During operation, the self test function can be started by pressing the test button (in-
ternal or external). The self test can also be started automatically every hour or every 24
hours by selecting the "ISO ADVANCED: Autotest:" menu.
The alarm relays 1/2 only switch after starting the self test function by pressing the test
button, that means the relays do not switch when an automatic self test has been star-
ted.
3.4.3 Current output for external measuring instrument
The isoPV utilises a current output electrically isolated from the device electronics 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 40. In addition, the centre scale mark can be set to 28kΩ
or 120kΩ, related to an external measuring instrument.
Alarm message Description Actions
Connection PE?
No low-resistance con-
nection between the
terminals and KE
and the earth (PE).
1. Check the wiring of the terminals
and KE and the earth (PE)
2. Press the "TEST" button
3. Switch the supply voltage off and on
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 and
off, a reset of the sequence control system can be carried out by pressing
the buttons "RESET", "MENU" and "TEST" sequentially.

Function
19
isoPV_D00024_02_M_XXEN/07.2018
3.4.4 Real-time clock
The real-time clock serves as a time base for the memory and self test functions. First,
the correct time and date must be set in the "ISO ADVANCED" menu. If time and date
are not set, a "C" (clock) is flashing in the standard display. In the event of a supply vol-
tage 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 automatically carried out every full hour.
3.4.5 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 interconnec-
ted via coupling switches, make sure that ISOMETER®s not currently used are disconnec-
ted from the IT system and deactivated. IT systems coupled via diodes or capacitances
may also influence the insulation monitoring process so that a central control of the dif-
ferent ISOMETER®s is required.
3.4.6 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 connections to the coupling
device AK1/AK2 are switched off via internal coupling relays, the measuring function is
stopped and the message "STANDBY" appears on the display. Instead of the most re-
cently measured value the value > 1 MW will be indicated. Furthermore, the alarm re-
lays and alarm LEDs stop signalling 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 selectively individual isoPVs via auxiliary con-
tacts of the respective coupling switch. One coupling switch each in a line-type or ring-
type arrangement can deactivate a subsequent isoPV to ensure that only one
ISOMETER®is active in each galvanically connected IT system.
If in a ring-type arrangement all coupling switches are closed, theoretically all

Function
20 isoPV_D00024_02_M_XXEN/07.2018
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 insulation mo-
nitoring function of the master ISOMETER®and hence the function input F1/F2 of the
master are without function in this mode. Details are illustrated in the graphic below:
BMS bus (A/B, RS485)
F1/F2
PE PE
PE PE
IT System 1 IT System 2
IT System 3IT System 4
G
G
G
G
Addr. 1 Addr. 2
Addr. 4 Addr. 3
iso-PV
AGH-PV iso-PV
AGH-PV
iso-PV
AGH-PV iso-PV
AGH-PV
F1/F2
F1/F2 F1/F2