Bender ISOMETER isoPV425 with AGH420 User manual

EN
Manual
ISOMETER® isoPV425
with AGH420 coupling device
Insulation monitoring device for unearthed
DC circuits (IT systems)
for photovoltaic systems up to 3(N)AC, AC 690 V / DC 1000 V
Software version: D404 V2.xx
isoPV425_D00028_09_M_XXEN/05.2018

Bender GmbH & Co. KG
Londorfer Str. 65 • 35305 Gruenberg • Germany
P.O. Box 1161 • 35301 Gruenberg • 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!

Table of Contents
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isoPV425_D00028_09_M_XXEN/05.2018
1. Important information .................................................................................... 6
1.1 How to use this manual ................................................................................. 6
1.2 Technical support: Service and support .................................................. 7
1.2.1 First level support ............................................................................................. 7
1.2.2 Repair service ..................................................................................................... 7
1.2.3 Field service ........................................................................................................ 8
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 ............................................................................................................ 11
2. Safety instructions ......................................................................................... 12
2.1 General safety instructions ........................................................................ 12
2.2 Work activities on electrical installations ............................................. 12
2.3 Intended use ................................................................................................... 13
3. Function ........................................................................................................... 14
3.1 Device characteristics .................................................................................. 14
3.2 Functional description ................................................................................ 15
3.2.1 Monitoring the insulation resistance ..................................................... 16
3.2.2 Undervoltage/overvoltage monitoring ................................................ 17
3.2.3 Self test/error codes ..................................................................................... 17
3.2.4 Malfunction ..................................................................................................... 20
3.2.5 Signalling assignment of the alarm relays K1/K2 .............................. 20
3.2.6 Measuring and response times ................................................................ 21
3.2.7 Password protection (on, OFF) ................................................................. 22
3.2.8 Factory setting FAC ...................................................................................... 22
3.2.9 External, combined test or reset button T/R ....................................... 22

Table of Contents
4isoPV425_D00028_09_M_XXEN/05.2018
3.2.10 Fault memory .................................................................................................. 23
3.2.11 History memory HiS ...................................................................................... 23
3.2.12 Interface/protocols ...................................................................................... 23
4. Installation, connection and commissioning ........................................... 25
4.1 Installation ....................................................................................................... 25
4.2 Wiring diagram .............................................................................................. 27
4.3 Commissioning .............................................................................................. 30
5. Operation of the device ............................................................................... 31
5.1 Display elements in use .............................................................................. 32
5.2 Menu structure ............................................................................................... 33
5.3 Menu "AL" ........................................................................................................ 34
5.3.1 Response value setting ............................................................................... 34
5.4 Menu "out" ....................................................................................................... 35
5.4.1 Configuration of the relay operating mode ........................................ 35
5.4.2 Relay alarm assignment "r1" and "r2" and LED assignment ........... 35
5.4.3 Fault memory configuration .................................................................... 36
5.4.4 Interface configuration .............................................................................. 37
5.5 Menu "t" ............................................................................................................ 37
5.5.1 Time configuration ....................................................................................... 37
5.6 Menu "SEt" ....................................................................................................... 38
5.6.1 Function configuration ............................................................................... 38
5.7 Measuring value display and history memory .................................... 38
6. Data access using the BMS protocol .......................................................... 40

Table of Contents
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isoPV425_D00028_09_M_XXEN/05.2018
7. Data access using the Modbus RTU protocol ........................................... 41
7.1 Reading out the Modbus register from the ISOMETER® ................. 41
7.1.1 Master sends a command to the ISOMETER® ...................................... 41
7.1.2 ISOMETER® answers the master ............................................................... 42
7.2 Writing to Modbus registers (parameter setting) .............................. 42
7.2.1 Master sends a command to the ISOMETER® ...................................... 42
7.2.2 ISOMETER® answer to the master ............................................................ 43
7.3 Exception code ............................................................................................... 43
7.3.1 Structure of the exception code .............................................................. 43
8. Modbus register assignment of the ISOMETER® ...................................... 44
8.1 ISOMETER® device-specific data type .................................................... 49
8.1.1 Device name ................................................................................................... 49
8.1.2 Measuring values .......................................................................................... 50
8.1.2.1 Float = Floating point value of the channels .............................. 50
8.1.2.2 AT&T = Alarm type and test type (internal/external) .............. 51
8.1.2.3 R&U = Range and unit ......................................................................... 52
8.1.3 Alarm assignment of the relays ................................................................ 53
8.2 Channel descriptions ................................................................................... 54
9. IsoData data string ........................................................................................ 56
10. Technical data .............................................................................................. 58
10.1 Tabular presentation .................................................................................... 58
10.2 Standards, approvals and certifications ................................................ 64
10.3 Ordering data ................................................................................................. 65

6isoPV425_D00028_09_M_XXEN/05.2018
1. Important information
1.1 How to use this manual
Always keep this manual within easy reach for future reference.
To make it easier for you to understand and revisit certain sections in this man-
ual, we have used symbols to identify important instructions and information.
The meaning of these symbols is explained below:
This manual is intended for electrically skilles persons
working in electrical engineering and electronics.
DANGER
This signal word indicates that there is a high risk of danger
that will result in death or serious injury if not avoided.
WARNING
This signal word indicates a medium risk of danger that
can lead to death or serious injury if not avoided.
CAUTION
This signal word indicates a low level risk that can result in
minor or moderate injury or damage to property if not
avoided.

Important information
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isoPV425_D00028_09_M_XXEN/05.2018
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
Telefon: [phone]*
Fax: [phone]
In Germany only: 0700BenderHelp (Tel. and Fax)
E-mail: [e-mail]
1.2.2 Repair service
 Repair, calibration, update and replacement service for Bender prod-
ucts
 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 warranty for Bender devices with in-house repair service or
replacement device at no extra cost
This symbol denotes information intended to assist the user
in making optimum use of the product.

Important information
8isoPV425_D00028_09_M_XXEN/05.2018
Telefon: [phone]** (technical issues)
[phone]**, -785** (sales)
Fax: [phone]
E-mail: [e-mail]
1.2.3 Field service
On-site service for all Bender products
 Commissioning, parameter setting, maintenance, troubleshooting for
Bender products
 Analysis of the electrical installation in the building (power quality test,
EMC test, thermography)
 Training courses for customers
Telefon: [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)
**Mon-Thurs 7.00 a.m. - 8.00 p.m., Fr 7.00 a.m. - 13.00 p.m.

Important information
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isoPV425_D00028_09_M_XXEN/05.2018
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 "Soft-
wareklausel zur Überlassung von Standard-Software als Teil von Lieferungen,
Ergänzung und Änderung der Allgemeinen Lieferbedingungen für Erzeug-
nisse und Leistungen der Elektroindustrie" (software clause in respect of the
licensing of standard software as part of deliveries, modifications and changes
to general delivery conditions for products and services in the electrical indus-
try) set out by the ZVEI (Zentralverband Elektrotechnik- und Elektronikindus-
trie e.V.) (German Electrical and Electronic Manufacturers' Association) also
applies.
Sale and delivery conditions can be obtained from Bender in printed or elec-
tronic format.
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 tem-
peratures can be ensured.

Important information
10 isoPV425_D00028_09_M_XXEN/05.2018
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 follow-
ing 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
manufacturer.
 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 recom-
mended by the manufacturer.
This operating manual, especially the safety instructions, must be observed by
all personnel working on the device. Furthermore, the rules and regulations
that apply for accident prevention at the place of use must be observed.

Important information
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isoPV425_D00028_09_M_XXEN/05.2018
1.7 Disposal
Abide by the national regulations and laws governing the disposal of this de-
vice. Ask your supplier if you are not sure how to dispose of the old equip-
ment.
The directive on waste electrical and electronic equipment (WEEE directive)
and the directive on the restriction of certain hazardous substances in electri-
cal and electronic equipment (RoHS directive) apply in the European Commu-
nity. In Germany, these policies 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 disposed of in accordance with the regulations.
 Old electrical and electronic equipment from users other than private
households which was introduced to the market after
13th August 2005 must be taken back by the manufacturer and dis-
posed of properly.
For more information on the disposal of Bender devices, refer to our
homepage at www.bender.de -> Service & support.

12 isoPV425_D00028_09_M_XXEN/05.2018
2. Safety instructions
2.1 General safety instructions
Part of the device documentation in addition to this manual is the enclosed
"Safety instructions for Bender products".
2.2 Work activities on electrical installations
If the device is used outside the Federal Republic of Germany, the applicable
local standards and regulations must be complied with. The European stand-
ard EN 50110 can be used as a guide.
Only skilled persons are permitted to carry out the
work necessary to install, commission and run a
device or system.
DANGER
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.

Safety instructions
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isoPV425_D00028_09_M_XXEN/05.2018
2.3 Intended use
The ISOMETER® of the isoPV425 series monitors the insulation resistance RF of
unearthed AC/DC main circuits (IT systems) with nominal system voltages of
3(N)AC, AC/DC 0 … 690 V or DC 0 …1000 V. DC components existing in
3(N)AC, AC/DC systems do not influence the operating characteristics, when
a minimum load current of DC 10 mA flows. A separate supply voltage Us al-
lows de-energised systems to be monitored as well. The ISOMETER® is always
used in conjunction with the AGH420.
To ensure that the ISOMETER® functions correctly, an internal
resistance of
≤ 1 kΩ must exist between L1/+ and L2/- via the
source (e.g. the transformer) or the load.

14 isoPV425_D00028_09_M_XXEN/05.2018
3. Function
3.1 Device characteristics
 Monitoring for unearthed AC and DC systems with galvanically con-
nected rectifiers or inverters
 Measurement of the nominal system voltage Un (True RMS) with und-
ervoltage and overvoltage detection
 Measurement of residual voltages system to earth (L+/PE and L-/PE)
 Automatic adaptation to the system leakage capacitance Ce up to
1000 µF
 Automatic device self-test with connection monitoring
 Selectable start-up delay, response delay and delay on release
 Two separately adjustable response value ranges of 1kΩ …500 kΩ
(Alarm 1, Alarm 2)
 Alarm signalling via LEDs („AL1“, „AL2“), a display and alarm relays
(„K1“, „K2“)
 N/C operation or N/O operation of the relays selectable
 Measured value indication via multi-functional LCD
 Fault memory can be activated
 RS-485 (galvanically isolated) including the following protocols:
– BMS interface (Bender measuring device interface) for data
exchange with other Bender components
– Modbus RTU
– IsoData (for continuous data output)
 Password protection to prevent unauthorised parameter changes

Function
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isoPV425_D00028_09_M_XXEN/05.2018
3.2 Functional description
The ISOMETER® measures the insulation resistance RF and the system leakage
capacitance Ce between the system to be monitored (L1/+, L2/-) and earth
(PE). The RMS value of the nominal system voltage Un between L1/+ and L2/-
as well as the residual voltages UL1e (between L1/+ and earth) and UL2e
(between L2/- and earth) are also measured.
From a minimum value of the nominal system voltage, the ISOMETER® deter-
mines the faulty conductor "R %", which shows the distribution of the insula-
tion resistance between conductors L1/+ and L2/-. The distribution is
indicated by a positive or negative sign preceding the insulation resistance
measurement. The value range of the faulty conductor is ±100 %:
The partial resistances can be calculated from the total insulation resistance RF
and the faulty conductor (R %) using the following formula:
Also from a minimum value of the nominal system voltage, the ISOMETER® de-
termines the insulation resistance RUGF from the residual voltages UL1e and
UL2e. It is an approximate value for one-sided insulation faults and can be used
as a trend indicator in cases where the ISOMETER® has to adapt to an RF and
Ce relation that varies considerably.
It is possible to assign the detected fault or the faulty conductor to an alarm
relay via the menu. If the values RF or Un exceed the response values activated
in the "AL" menu, this will be indicated by the LEDs and relays "K1" and "K2"
according to the alarm assignment set in the "out" menu. In addition, the op-
eration of the relay (n.o. / n.c.) can be set and the fault memory "M", activated.
If the values RF or Un do not exceed their release value (response value plus
hysteresis) for the period toff without interruption, the alarm relays will
Display Description
–100 % one-sided fault at conductor L2/-
0 % symmetrical fault
+100 % one-sided fault at conductor L1/
+
Fault at conductor L1/+ RL1F = (200 % * RF)/(100 % + R %)
Fault at conductor L2/- RL2F = (200 % * RF)/(100 % – R %)

Function
16 isoPV425_D00028_09_M_XXEN/05.2018
switch back to their initial position and the alarm LEDs "AL1"/"AL2" stop
lighting. If the fault memory is activated, the alarm relays remain in the alarm
condition and the LEDs light until the reset button "R" is pressed or the supply
voltage is interrupted.
The device function can be tested using the test button "T". Parameters are as-
signed to the device via the LCD and the control buttons on the front panel;
this function can be password-protected. Parameterisation is also possible via
the BMS bus, for example by using the BMS Ethernet gateway (COM465IP) or
the Modbus RTU.
3.2.1 Monitoring the insulation resistance
The two parameters that monitor the insulation resistance, "R1" and "R2", can
be found in the response value menu "AL" (see table in Chapter 5.3). The value
R1 can only be set higher than the value R2. If the insulation resistance RF
reaches or falls below the activated values R1 or R2, an alarm message will be
signalled. If RF exceeds the values R1 or R2 plus the hysteresis value (see the
table in Chapter 5.3.1), the alarm will be cleared.
The isoPV 425 determines the system leakage capacitance Ce
through an impedance measurement whose frequency is
adjusted to the most accurate insulation measured value
possible. The measurement signal is affected if it goes
through a rectifier or inverter, and this can lead to phase
errors that may result in an incorrect system leakage
capacitance value.

Function
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isoPV425_D00028_09_M_XXEN/05.2018
3.2.2 Undervoltage/overvoltage monitoring
In the response value menu "AL" (see Chapter 5.3), the parameters ("U <" and
"U >") for monitoring the nominal system voltage Un can be activated or de-
activated. The maximum undervoltage value is limited by the overvoltage
value.
The r.m.s. value of the nominal system voltage Un is monitored. If the nominal
system voltage Un reaches, falls below or exceeds the limit values ("U <" or
"U >"), an alarm will be signalled. If the maximum permissible nominal system
voltage Un set for the ISOMETER® is exceeded, an alarm message will be initi-
ated even when the overvoltage limit value has been deactivated. The alarm
will be deleted when the limit values plus hysteresis (see Chapter 5.3.1) are no
longer violated.
3.2.3 Self test/error codes
The integrated self test function checks the function of the insulation moni-
toring device, and connection monitoring checks the connections to the sys-
tem to be monitored. The alarm relays are not switched during the self test.
This can be changed using the parameter "test" in the alarm assignment
(menu "out", Chapter 5.4.2). During the test, the display indicates "tES".
When malfunctions are detected or connections are missing, the LEDs "ON"/
"AL1"/"AL2" flash. The respective error codes ("E.xx") will be indicated on the
display and the relay "K2" switches.
The relays can be assigned to a device error with the parameter "Err" in the
"out" menu in the alarm assignment.

Function
18 isoPV425_D00028_09_M_XXEN/05.2018
Error codes
If, contrary to expectations, a device error should occur, error codes will ap-
pear on the display. Some of these are described below:
Error code Description
E.01
PE connection error
The connections "E" or "KE" to earth are interrupted.
Action:
Check connection, eliminate error. The error code will be
erased automatically once the error has been eliminated.
E.02
Connection fault system (L1/+ , L2/-),
The internal resistance of the system is too high, the con-
nection "L1/+" or "L2/-" to the system is interrupted or L1/+
and L2/- are connected in reverse polarity to the DC System to
be monitored (Un < -100 V).
Action:
Check connection, eliminate error. The error code will be
erased automatically once the error has been eliminated.
E.05 Measurement technique error/calibration invalid
For the current software version
E.07
The maximum permissible system leakage capacitance
Ce is exceeded
Action:
Device not suitable for the existing system leakage capaci-
tance Ce: uninstall device.
E.08
Calibration error during device test
Action:
If the error continues to exist after checking the device con-
nections, there is an error inside the device.

Function
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isoPV425_D00028_09_M_XXEN/05.2018
Internal device errors "E.xx" can be caused by external disturbances or inter-
nal hardware errors. If the error message occurs again after restarting the
device or after a reset to factory settings (menu item "FAC") , the device must
be repaired.
After eliminating the fault, the alarm relays switch back automatically or by
pressing the reset button.
The self test can take a few minutes. It can be suppressed for the duration of
the device start by setting the parameter in the menu "SEt" to "S.Ct = off". This
allows the ISOMETER® to enter measurement mode quickly after connecting
the supply voltage Us.
Automatic self test
The device runs a self test after connecting the power supply and then every
24 h (selectable: off, 1h, 24 h).
Manual self test
A self test is initiated by pressing the test button "T" for a period greater than
1.5 s. While pressing the internal test button, all display elements available for
this device are shown.
Connection monitoring
Connection monitoring, activated by the self test, checks the connections of
terminals "E" and "KE" to the protective earth conductor (PE).
When an error is detected, the message device error ("Err") will be signalled
and the error code "E.01" appears on the display.
The system connection monitoring is used to check the connection of termi-
nals "L1/+" and "L2/-" to the system to be monitored. When an interruption or
a high-resistance connection between L1/+ and L2/- is detected via the inter-
nal resistance of the system, the device error ("Err") will be signalled and the
error code "E.02" appears on the display. Since a test of the system connection
may take considerable time due to system disturbances or may even provide
incorrect results, the system connection monitoring can be disconnected us-
ing the parameter "nEt" in the "SEt" menu.

Function
20 isoPV425_D00028_09_M_XXEN/05.2018
3.2.4 Malfunction
In addition to the self test described above, several functions in the insulation
monitoring device are continuously checked during operation. If a fault is de-
tected, the device error ("Err") will be signalled, the error code "E.xx" appears
on the display as an identifier for the error type xx and the LEDs "ON"/"AL1"/
"AL2" will flash. If the error occurs again after restarting the device or after a
reset to factory settings, then contact Bender Service.
3.2.5 Signalling assignment of the alarm relays K1/K2
The messages "device error", "insulation fault", "insulation impedance fault",
"undervoltage/overvoltage fault", "device test" or "device start with alarm"
can be assigned to the alarm relays via the "out" menu. An insulation fault is
indicated by the messages "+R1", "-R1", "+R2" and "-R2". Messages "+R1" and
"+R2" indicate an insulation fault assigned to conductor L1/+, and the mes-
sages "-R1" and "-R2" indicate an insulation fault assigned to conductor L2/-. If
an assignment is not possible, for example in the event of a symmetrical insu-
lation fault, the messages corresponding to + and - are shown together.
The message "test" indicates a self test.
The message "S.AL" indicates a so-called "device start with alarm". After con-
necting to the supply voltage Us and setting the parameter value to
"S.AL = on", the ISOMETER® starts with the insulation measurement value
RF = 0 Ω and sets all activated alarms.
The alarms will be cleared only when the measured values are up-to-date and
no thresholds are exceeded. In the factory setting "S.AL = off", the ISOMETER®
starts without an alarm.
It is recommended that the value set for the "S.AL" parameter value is identi-
cal for both relays.