Bender ISOMETER isoPV with AGH-PV User manual

EN
Manual
isoPV_D00024_00_M_XXDE/06.2015
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

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

3
Table of Contents
isoPV_D00024_00_M_XXDE/06.2015
1. Safety instructions .................................................................................. 7
1.1 Intended use ............................................................................................................. 7
1.1.1 Personnel .................................................................................................................... 7
1.1.2 Hazards when handling the ISOMETER® isoPV ............................................. 7
1.1.3 Note .............................................................................................................................. 8
1.2 Explanations of symbols and notes .................................................................. 8
1.3 Directions for installation ..................................................................................... 9
2. Function ................................................................................................. 11
2.1 Features isoPV ......................................................................................................... 11
2.2 Features AGH-PV .................................................................................................... 12
2.3 Product description .............................................................................................. 12
2.4 Description of function ....................................................................................... 12
2.4.1 Measurement profiles .......................................................................................... 13
2.4.2 Self test ...................................................................................................................... 14
2.4.3 Current output for external measuring instrument .................................. 15
2.4.4 Real-time clock ....................................................................................................... 15
2.4.5 Coupled IT systems ............................................................................................... 15
2.4.6 Function input F1/F2 for connection or disconnection of
IT systems being monitored .............................................................................. 16
2.4.7 ISOnet function (COM SETUP) ........................................................................... 18
3. Commissioning flow chart (threepart) ............................................. 19
4. Installation and connection ............................................................... 23
4.1 Installation of the isoPV ....................................................................................... 23
4.2 Wiring diagram ....................................................................................................... 23

Table of Contents
4isoPV_D00024_00_M_XXDE/06.2015
5. Operation and setting .......................................................................... 27
5.1 Display and operating elements ...................................................................... 27
5.1.1 Display in standard mode ................................................................................... 28
5.1.2 Display in menu mode ......................................................................................... 28
5.1.3 Function buttons ................................................................................................... 29
5.2 Menu structure and menu mode ..................................................................... 31
5.2.1 Navigation within the menu .............................................................................. 31
5.2.2 Parameter change ................................................................................................. 31
5.2.3 Changing from the menu mode to the standard mode ......................... 31
5.2.4 Diagram menu structure ..................................................................................... 32
5.3 Menu HISTORY INFO ............................................................................................. 33
5.3.1 Diagram HISTORY INFO ....................................................................................... 34
5.4 Menu ISO SETUP: Setting of the basic ISOMETER functions .................. 35
5.4.1 Response values Alarm1 and Alarm2 ............................................................. 35
5.4.2 Operating principle of the alarm relays ......................................................... 35
5.4.3 Memory setting (on/off) ...................................................................................... 37
5.4.4 Current output for external measuring instruments ................................ 37
5.4.5 Matching the current output to the centre scale mark of external
measuring instruments ....................................................................................... 37
5.5 Menu ISO ADVANCED: Setting of the extended functions .................... 39
5.5.1 External coupling device (AGH: PV) ................................................................ 39
5.5.2 Adaptation of the system leakage capacitance (Cemax: 2000 μF) ..... 39
5.5.3 Changing the measurement method (Measure: AMP4) ......................... 39
5.5.4
Setting the repetition time for the automatic self test (Autotest: 24h) 41
5.5.5 Setting the real-time clock (Clock) .................................................................. 41
5.5.6 Setting the date (Date) ........................................................................................ 41
5.5.7 Specifying the start-up time for the automatic self test (Test) .............. 41
5.5.8 Diagram ISO ADVANCED .................................................................................... 42
5.6 Menu COM SETUP: Setting the BMS interface ............................................ 43
5.6.1 Bus address "Addr:" ............................................................................................... 43
5.6.2 ISOnet function ...................................................................................................... 43
5.6.3 ISO monitor .............................................................................................................. 43
5.6.4 Diagram COM SETUP ............................................................................................ 44
5.7 PASSWORD menu .................................................................................................. 45

Table of Contents
5
isoPV_D00024_00_M_XXDE/06.2015
5.7.1 Setting and activating the password ............................................................. 45
5.7.2 PASSWORD diagram ............................................................................................ 45
5.8 LANGUAGE Menu ................................................................................................. 46
5.8.1 Language setting ................................................................................................... 46
5.8.2 Language diagram ................................................................................................ 46
5.9 SERVICE menu ......................................................................................................... 46
6. Serial interface ...................................................................................... 47
6.1 RS-485 interface with BMS protocol ............................................................... 47
6.2 Topology RS-485 network .................................................................................. 48
6.2.1 Correct arrangement ............................................................................................ 48
6.2.2 Wrong arrangement ............................................................................................. 48
6.2.3 Wiring ......................................................................................................................... 48
6.3 BMS protocol ........................................................................................................... 49
6.3.1 BMS master .............................................................................................................. 49
6.3.2 BMS slave ..................................................................................................................50
6.3.3 Commissioning of an RS-485 network with BMS protocol .................... 51
7. Coupled PV generators (application example) .............................. 53
8. Technical data isoPV with AGH-PV ................................................... 55
8.1 Data in tabular form isoPV ................................................................................. 55
8.2 Technical data in tabular form AGH-PV ......................................................... 59
8.3 Standards, approvals and certifications ........................................................ 60
8.4 Characteristic curves ............................................................................................ 61
8.5 Ordering information ........................................................................................... 65
INDEX ........................................................................................................... 67

7
isoPV_D00024_00_M_XXDE/06.2015
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 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
1.1.1 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 under-
stood the safety section and warning information in this operating manual.
1.1.2 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
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.
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.

Safety instructions
8isoPV_D00024_00_M_XXDE/06.2015
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 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®.
1.2 Explanations of symbols and notes
To make it easier for you to understand and revisit certain sections of text and in-
structions in this manual, we have used symbols to identify important instructions
and information. Examples of how symbols are used is explained below:
Information which refers to hazards are highlighted with the warning
symbol.
Information which is designed to help you make the best use of the
product is highlighted with the information symbol.

Safety instructions
9
isoPV_D00024_00_M_XXDE/06.2015
1.3 Directions for installation
The terminals and KE have to be connected by a separate wire to the protective
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 disconnected from the pro-
tective conductor (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 resist-
ance, 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 intercon-
nected 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) =4kΩ/ 1 kΩ
ISO SETUP: Operating mode K1/K2 = N/O operation (N.O.)
ISO SETUP: Memory = off
ISO ADVANCED: System leakage capacitance
Measurement method
=
=
2000 μF
AMP4
COM SETUP: Bus address = 3 (slave)

Safety instructions
10 isoPV_D00024_00_M_XXDE/06.2015
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
------------------------------------------=

11
isoPV_D00024_00_M_XXDE/06.2015
2. Function
2.1 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 kΩeach
(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)...20mA (electrically isolated) in relation to the measured
insulation value
AMPPlus

Function
12 isoPV_D00024_00_M_XXDE/06.2015
2.2 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...1100 V
DIN rail mounting
2.3 Product description
The ISOMETER®type isoPV in combination with the AGH-PV coupling device mon-
itors 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 converters or thyristor-controlled DC drives. The adaptation to the existing sys-
tem leakage capacitances takes place automatically.
Only use the AGH-PV coupling device supplied with the device for adaptation of
the nominal voltage range.
isoPV can share the BMS bus with other bus devices.
2.4 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 but-
tons. The parameters are indicated on the LC display and are stored in a non-vola-
tile 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 ampli-
tude. The period depends on the respective system leakage capacitances and the
insulation resistance of the system to be monitored.
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
13
isoPV_D00024_00_M_XXDE/06.2015
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 kΩmeasuring instrument after the measuring time has ex-
pired.
The measuring time is dependent on the selected measurement method, the sys-
tem leakage capacitance, the insulation resistance and the system-related distur-
bances.
System leakage capacitances do not influence the measuring accuracy.
If the reading is below the selected response values Alarm 1/Alarm 2, the associat-
ed alarm relays respond, the LEDs "Alarm 1/2“ light up and the measuring 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 con-
tact] or wire jumper), the fault message will be stored. Pressing the reset button, re-
sets the fault message, provided that the insulation resistance is at least above 25
% and at least 1 kΩabove 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 (Euro-
pean Patent: EP 0 654 673 B1).
2.4.1 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 39.
AMPPlus
AMPPlus

Function
14 isoPV_D00024_00_M_XXDE/06.2015
2.4.2 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 comprehen-
sive 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 pa-
rameter 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 system conditions, the self test is completed after
15...20 seconds, then the message "Test ok!" appears on the display for approxi-
mately 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
display, the device error LED lights, the relay K2 (21-22-24) switches and the corre-
sponding 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.
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:" 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 started.
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

Function
15
isoPV_D00024_00_M_XXDE/06.2015
2.4.3 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 36. In addition, the centre scale mark can be set to
28kΩor 120kΩ, related to an external measuring instrument.
2.4.4 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 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 automatically 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 intercon-
nected via coupling switches, make sure that ISOMETER®s not currently used are
disconnected 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 different ISOMETER®s is required.
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
16 isoPV_D00024_00_M_XXDE/06.2015
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 connections to the
coupling device AK1/AK2 are switched off via internal coupling relays, the measur-
ing function is stopped and the message "STANDBY" appears on the display. In-
stead of the most recently measured value the value > 1 MΩwill be indicated.
Furthermore, the alarm relays and alarm LEDs stop signalling alarm messages.
After opening the function input F1/F2, the connection to the IT system will be re-
stored and a completely new insulation resistance measurement cycle is started.
This function can be used to disconnect selectively individual isoPVs via auxiliary
contacts 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
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 monitoring
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:

Function
17
isoPV_D00024_00_M_XXDE/06.2015
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

Function
18 isoPV_D00024_00_M_XXDE/06.2015
2.4.7 ISOnet function (COM SETUP)
To activate this function, select "ISOnet=ON" in the COM SETUP menu. This func-
tion 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 ISOME-
TER®s influence each other in interconnected IT systems. In comparison to a solu-
tion with coupling switches and function input 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. Further-
more, this solution is recommended for IT systems coupled via capacitances or di-
odes.
Each ISOnet slave checks the network for an ISOnet master. If there is no master
available, the display will show the fault message "ISOnet Master?" With the ISOnet
function activated, the function input F1/F2 is automatically deactivated.
BMS bus (A/B, RS-485)
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

19
isoPV_D00024_00_M_XXDE/06.2015
3. Commissioning flow chart (threepart)
Due to limitations of space, the three-part flow chart begins on the next page.

Commissioning flow chart (threepart)
20 isoPV_D00024_00_M_XXDE/06.2015
The encircled figures in the flow chart correspond to the figures in the legend to the
wiring diagram.
Commissioning of the ISOMETER®(1)
7
Is the system to be monitored an
unearthed system (IT system)? isoPV is not suitable for this application( contact Bender)
Device connection Optional device
connection
no
no
yes
The terminals AK and AK2 must be
connected by means of an AGH-PV
to Un of the system to be monitored
An external kW measuring instrument
at M+/M-
Scale centre point: 28 kW or 20 kW
Output current: 0/4...20 mA
Connect the supply voltage Us
to the terminals A /+ and A2/-. Consider
the details indicated on the nameplate.
External TEST button (NO contact)
to the terminals T and T2
External RESET button (NC contact)
to the terminals R and R2
The output contacts of the alarm relays
System fault (2 -22-24)
Alarm ( - 2- 4)
Alarm 2 (2 -22-24)
When using the RS485 interface, take
care that a 20 W resistor is connected
at the beginning and the end of the
network.
3
2
8
0
Deenergize the installation
before connecting the device!
Recommended wire cross section
of connecting cable
single wire 0.2...4 mm2
flexible 0.2... 2.5 mm2
Is the maximum nominal voltage
Un AC 793 V
and is Un DC 00 V
yes
The two PE connections and KE
must be connected separately to the
equipotential bonding.
6
2
3
4
5
isoPV is not suitable for this
application( contact Bender)