Bender ISOMETER isoHV525-M4-4 User manual

Manual
EN
ISOMETER® isoHV525
Insulation monitoring device for unearthed
AC, AC/DC, and DC systems (IT systems)
up to 3(N)AC, AC/DC 0...1000 V or DC 0...1000 V
Software versions: D0500 V1.xx (isoHV525-M4-4)
D0453 V1.xx (isoHV525-S4-4)
isoHV525_D00297_05_M_XXEN/08.2019

Bender GmbH & Co. KG
P.O. Box 1161 • 35301 Gruenberg • Germany
Londorfer Str. 65 • 35305 Gruenberg • 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
isoHV525_D00297_05_M_XXEN/08.2019
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 ................................................................................................. 8
1.4 Delivery conditions ........................................................................................... 8
1.5 Inspection, transport and storage ............................................................... 8
1.6 Warranty and liability ....................................................................................... 9
1.7 Disposal ................................................................................................................. 9
2. Safety instructions ............................................................................... 10
2.1 General safety instructions .......................................................................... 10
2.2 Work activities on electrical installations ................................................ 10
2.3 Intended use ..................................................................................................... 11
3. Function ................................................................................................. 12
3.1 isoHV525-M4-4 ................................................................................................. 12
3.1.1 Features .............................................................................................................. 12
3.1.2 Function description ...................................................................................... 12
3.1.2.1 Manual self test ............................................................................................... 12
3.1.2.2 Malfunction ...................................................................................................... 13
3.1.2.3 Signalling assignment of the alarm relays K1/K2 ............................... 13
3.1.2.4 Measuring and response times ................................................................. 13
3.1.2.5 External, combined Test or Reset button T/R ...................................... 13
3.1.2.6 Analogue output ............................................................................................ 14
3.2 isoHV525-S4-4 .................................................................................................. 15
3.2.1 Device features ................................................................................................. 15

Inhaltsverzeichnis
4isoHV525_D00297_05_M_XXEN/08.2019
3.2.2 Function description ...................................................................................... 15
3.2.2.1 Manual self test ............................................................................................... 16
3.2.2.2 Malfunction ...................................................................................................... 17
3.2.2.3 Signalling assignment of the alarm relays K1/K2 ............................... 17
3.2.2.4 Measuring and response times ................................................................. 17
3.2.2.5 External, combined Test or reset button T/R ....................................... 18
3.2.2.6 Fault memory .................................................................................................. 18
3.2.2.7 Interface/protocols ....................................................................................... 19
4. Installation, connection and commissioning .................................. 21
4.1 Mounting ............................................................................................................ 21
4.2 Connecting the device .................................................................................. 21
4.3 Commissioning ................................................................................................ 25
5. isoHV525-S4-4 parameter overview ................................................. 26
5.1 Setting the response value .......................................................................... 26
5.2 Configuration of the relay operating mode ........................................... 26
5.2.1 Alarm assignment "r1" and "r2" .................................................................. 27
5.2.2 Fault memory configuration ...................................................................... 27
5.3 Interface configuration ................................................................................. 28
5.4 Time configuration ......................................................................................... 28
5.5 Function configuration ................................................................................. 29
5.6 Measured value description ........................................................................ 29
6. Data access to the isoHV525-S4-4 using the
BMS protocol ......................................................................................... 30

Inhaltsverzeichnis
5
isoHV525_D00297_05_M_XXEN/08.2019
7. Data access to the isoHV525-S4-4 using the
Modbus RTU protocol ......................................................................... 31
7.1 Reading the Modbus register from the ISOMETER® ........................... 31
7.1.1 Master device sends a command to the ISOMETER® .......................... 31
7.1.2 The ISOMETER®s answers the Master ....................................................... 31
7.2 Writing to the Modbus register (parameter setting) .......................... 32
7.2.1 Master device sends a command to the ISOMETER® .......................... 32
7.2.2 The ISOMETER®s answers the Master ....................................................... 32
7.3 Exception code ................................................................................................. 33
7.3.1 Structure of the exception code ................................................................ 33
8. ISOMETER® Modbus register assignment ........................................ 34
8.1 Device-specific data type of the ISOMETER® ......................................... 37
8.1.1 Device name ...................................................................................................... 37
8.1.2 Measured value ................................................................................................ 38
8.1.2.1 Float = Floating point value of the channels ....................................... 38
8.1.2.2 AT&T = Alarm type and test type (internal/external) ........................ 38
8.1.2.3 R&U = Range and unit .................................................................................. 39
8.1.3 Alarm assignment of the relays .................................................................. 40
8.2 Channel description ....................................................................................... 41
9. IsoData data string ............................................................................... 43
10. Technical data .................................................................................... 44
10.1 Tabular representation .................................................................................. 44
10.2 Standards, approvals and certifications .................................................. 48
10.3 Ordering information ..................................................................................... 48

6isoHV525_D00297_05_M_XXEN/08.2019
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!
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 seriousinjury 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
This symbol denotes information intended to assist the user in making
optimum use of the product.

Important information
7
isoHV525_D00297_05_M_XXEN/08.2019
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]
In Germany only: 0700BenderHelp (Tel. and Fax)
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 warranty for Bender devices with in-house repair service or replace-
ment device at no extra cost
Telephone: [phone]** (technical issues)
[phone]**, -785** (sales)
Fax: [phone]
E-Mail: [email protected]
Please send all devices for repair to the following address:
Bender GmbH, Repair service,
Londorfer Str. 65,
35305 Gruenberg

Important information
8isoHV525_D00297_05_M_XXEN/08.2019
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
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 -> 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 Ände-
rung der Allgemeinen Lieferbedingungen für Erzeugnisse und Leistungen der Elektro-
industrie" (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 industry) set out by the ZVEI (Zentralverband Elektrotechnik-
und Elektronikindustrie e.V.) applies. Sales and delivery conditions can be obtained
from Bender in printed or electronic 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 temperatures can be ensured.

Important information
9
isoHV525_D00297_05_M_XXEN/08.2019
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
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 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 13th 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 -> Service & support.

10 isoHV525_D00297_05_M_XXEN/08.2019
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.
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
11
isoHV525_D00297_05_M_XXEN/08.2019
2.3 Intended use
The ISOMETER® isoHV525 monitors the insulation resistance RFof unearthed AC, AC/DC
and DC systems (IT systems) with nominal system voltages of 3(N)AC,
AC/DC 0 … 1,000 V or DC 0 …1,000 V. The maximum permissible system leakage capa-
citance Ceis 150 µF. DC components existing in AC systems do not influence the opera-
ting characteristics, when a minimum load current of DC 100 mA flows. A separate
supply voltage Usallows de-energised systems to be monitored, too.
Please heed the limits of the area of application indicated in the technical specifications.
Any use other than that described in this manual is regarded as improper.
Two variants of the isoHV525 ISOMETER®s are available:
 isoHV525-M4-4 with an analogue output
 isoHV525-S4-4 with a serial interface
Only skilled persons are permitted to carry out the work necessary
to install, commission and run a device or system.
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.
In the event of an alarm message of the ISOMETER®, the insulation fault
should be eliminated as quickly as possible.
If the ISOMETER® is installed inside a control cabinet, the insulation fault
message must be audible and/or visible to attract attention.

12 isoHV525_D00297_05_M_XXEN/08.2019
3. Function
3.1 isoHV525-M4-4
3.1.1 Features
 Monitoring the insulation resistance RFfor unearthed AC/DC systems
 Automatic adaptation to the system leakage capacitance Ceup to 150 µF
 Two separate response values for Alarm 1 and Alarm 2
 Alarms are signalled via alarm relays ("K1", "K2")
 0. . . 10 V analogue output (galvanically separated)
3.1.2 Function description
The ISOMETER® measures the insulation resistance RFand the system leakage capaci-
tance Cebetween the system to be monitored (L1/+, L2/-) and earth (PE). If the value RF
exceeds the set response values, this will be indicated by the relays "K1" and "K2".
If the insulation resistance RFexceeds the release value (response value plus hysteresis),
the alarm relays switch back to their initial position.
The device function can be tested using the Test/Reset button.
3.1.2.1 Manual self test
The integrated self test function tests the function of the insulation monitoring device
and the connection to earth. A self test is started by pressing the external Test/Reset
button. Relay 1 ("K1") is switched during a manual self test. In the event of a fault, relay
2 ("K2") switches and the measuring function is interrupted.
Internal device errors can be caused by external disturbances or internal hardware er-
rors. After eliminating the fault, the alarm relays are automatically reset or are reset to
the initial position by pressing the Test/Reset button. The self test can take a few minu-
tes.
The isoHV525 determines the system leakage capacitance via an
impedance measurement whose frequency is adjusted to the most
accurate insulation measurement. The measurement signal is influenced
by rectifiers or inverters, and can lead to phase errors which in turn can
lead to a distorted system leakage capacitance value.

Function
13
isoHV525_D00297_05_M_XXEN/08.2019
3.1.2.2 Malfunction
In addition to the described self test, several functions in the insulation monitoring de-
vice are continuously checked during operation. If the error occurs again after restar-
ting the device, then contact Bender Service.
3.1.2.3 Signalling assignment of the alarm relays K1/K2
Pre-alarm and test are assigned to relay 1 ("K1"). The main alarm and device fault are as-
signed to relay 2 ("K2").
3.1.2.4 Measuring and response times
The measuring time is the period essential for the detection of the measured value. The
measuring time is reflected in the operating time tae. The measuring time for the insu-
lation resistance value is mainly determined by the required measuring pulse duration,
which depends on the insulation resistance and system leakage capacitance of the sys-
tem to be monitored. The measuring pulse is produced by the measuring voltage ge-
nerator, which is integrated in the ISOMETER®. System disturbances may lead to
extended measuring times.
Operating time tae
The operating time tae is the time required by the ISOMETER® to determine the meas-
ured value. For the measured insulation resistance value, it is dependent on the insula-
tion resistance and the system leakage capacitance.
3.1.2.5 External, combined Test or Reset button T/R
Reset= Press the external button < 1.5 s
Reset followed by a test = Press the external button > 1.5 s
Stop measuring function = Press and hold the external button
Only one ISOMETER® may be controlled via an external Test/Reset button. A galvanic
parallel connection of several test or reset inputs for testing multiple insulation monito-
ring devices is not allowed.

Function
14 isoHV525_D00297_05_M_XXEN/08.2019
3.1.2.6 Analogue output
The isoHV-M4-4 ISOMETER® outputs and analogue voltage in the range 0. . .10 V .
Calculation of the insulation resistance using the analogue output:
Activation Setting Description
FAC
U 0 . . . 10 V 0 . . . 10 V, Permissible load > 20 k
on 120 k The scaled reference value for thr displayed non-
linear resistance at 50% of interface control..
Variable Description
RFInsulation fault in k
RSKM Scaled reference value in k (i.e. 120 k)
A1Upper analogue output value (i.e. 10 V)
A2Measured analogue output value
The analogue output provides stable output values only after the
isoHV525-M4-4 has been initialized.
A₁ x R
SKM
(kΩ)
A
R
F
(kΩ) = - R
SKM
(kΩ)

Function
15
isoHV525_D00297_05_M_XXEN/08.2019
3.2 isoHV525-S4-4
3.2.1 Device features
 Monitoring the insulation resistance RFfor unearthed AC/DC systems
 Measurement of the nominal system voltage Un(True RMS) with undervoltage
and overvoltage detection
 Measurement of residual voltages to earth (L1+/PE and L2-/PE)
 Automatic adaptation to the system leakage capacitance Ceup to 150 µF
 Two separate response values for Alarm 1 and Alarm 2
 Alarm are signalled via alarm relays ("K1", "K2")
 Selectable N/C or N/O relay operation
 Selectable start-up delay, response delay and delay on release
 Fault memory can be activated.
 RS-48 5 (galvanically isolated) with the following protocols:
– BMS interface (Bender measuring device interface) for data exchange with
other Bender components
– Modbus RTU
– IsoData (for continuous data output)
3.2.2 Function description
The ISOMETER® measures the insulation resistance RFand the system leakage capaci-
tance Cebetween the system to be monitored (L1/+, L2/-) and earth (PE). The RMS value
of the nominal system voltage Unbetween L1/+ and L2/-, as well as the residual volta-
ges UL1e (between L1/+ and earth) and UL2e (between L2/- and earth) are also measu-
red. From a minimum value of the nominal system voltage, the ISOMETER® determines
the faulty conductor L1/+ or L2/-, which shows the distribution of the insulation resis-
tance between conductors L1/+ and L2/-.
The value range of the faulty conductor is ±100 %:
Display Meaning
-100 % One-sided fault on conductor L2/-
0 % Symmetrical fault
+100 % One-sided fault on conductor L1/+

Function
16 isoHV525_D00297_05_M_XXEN/08.2019
The partial resistances can be calculated from the total insulation resistance RFand the
faulty conductor (R %) using the following formula:
Fault on conductor L1/+ ->RL1F = (200 % * RF)/(100 % + R %)
Fault on conductor L2/- -> RL2F = (200 % * RF)/(100 % – R %)
If the values RFor Unexceeds the set response values, this will be indicated by the relays
"K1" and "K2". In addition, the operation of the relay (n.c./n.o.) can be set and the fault
memory "M", activated. If the values RFor Unexceed their release value (response value
plus hysteresis) uninterrupted for no longer than the period toff, then the alarm relays
will switch back to their initial position. If the fault memory is enabled, the alarm relays
remain in the alarm state until the external Test/Reset button is pressed or until the sup-
ply voltage Usis switched off. The device function can be tested using the Test/Reset
button. Device parameters are initially assigned by Bender. Parameterisation of the ISO-
METER

isoHV525-S4-4 is also possible via the BMS bus, for example by means of a BMS-
Ethernet gateway (COM465IP) or Modbus RTU.
3.2.2.1 Manual self test
The integrated self test function tests the function of the insulation monitoring device
and the connection to IT system to be monitored. A self test is started by pressing the
external test/reset button. Relay 1 ("K1") is switched during a manual self test. In the
event of a fault, relay 2 ("K2") switches and the measuring function is interrupted.
Internal device errors can be caused by external disturbances or internal hardware er-
rors. After eliminating the fault, the alarm relays are automatically reset or are reset to
the initial position by pressing the Test/Reset button. The self test can take a few minu-
tes.
The isoHV525 determines the system leakage capacitance via an
impedance measurement whose frequency is adjusted to the most
accurate insulation measurement. The measurement signal is influenced
by rectifiers or inverters, and can lead to phase errors which in turn can
lead to a distorted system leakage capacitance value.

Function
17
isoHV525_D00297_05_M_XXEN/08.2019
3.2.2.2 Malfunction
In addition to the described self test, several functions in the insulation monitoring de-
vice are continuously checked during operation. If the error occurs again after restar-
ting the device or after restoring the factory settings, please contact Bender Service.
3.2.2.3 Signalling assignment of the alarm relays K1/K2
Pre-alarm and test are assigned to relay 1 ("K1"). The main alarm and device fault are
assigned to relay 2 ("K2").
3.2.2.4 Measuring and response times
The measuring time is the period essential for the detection of the measured value. The
measuring time is reflected in the operating time tae. The measuring time for the insu-
lation resistance value is mainly determined by the required measuring pulse duration,
which depends on the insulation resistance RFand system leakage capacitance Ceof
the system to be monitored. Measuring pulse is produced by the measuring pulse ge-
nerator integrated in the ISOMETER®. The measuring times for Ce, UL1e, UL2e and R % are
synchronous. System disturbances may lead to extended measuring times. In contrast,
the time for the nominal system voltage measurement Unis independent and consi-
derably shorter.
Response delay ton
The response delay ton can be set uniformly for all messages using the parameter "ton",
whereby each alarm message specified in the alarm assignment has its own timer for
ton. This delay time can be used for interference suppression in the case of short measu-
ring times. An alarm will only be signalled when a threshold value of the respective
measured value is exceeded for the period of ton without interruption. Every time the
threshold value is violated within the time ton, the response delay "ton" restarts once
again.
Operating time tae
The operating time tae is the time required by the ISOMETER® to determine the measu-
red value. For the measured insulation resistance value, it is dependent on the insulati-
on resistance RFand the system leakage capacitance Ce.
Total response time tan
The total response time tan is the sum of the operating time tae and the response delay
time ton.

Function
18 isoHV525_D00297_05_M_XXEN/08.2019
Delay-on release toff
The delay on release toff can be set uniformly for all messages using the parameter
"toff", whereby each alarm message specified in the alarm assignment has its own timer
for toff. An alarm will continuously be signalled until the threshold value of the respec-
tive measured value is not exceeded (including hysteresis) for the period of toff without
interruption. Each time the threshold value is not exceeded for the period of toff, the de-
lay on release "toff" restarts again.
Start-up delay t
After connection to the supply voltage US, the alarm indication for the preset time
(0…10 s) in the parameter "t" is suppressed.
3.2.2.5 External, combined Test or reset button T/R
Reset = Press the external button < 1.5 s
Reset with subsequent test = Press the external button > 1.5 s
Stop measuring function = Press and hold the external button.
Only one ISOMETER® may be controlled via an external Test/Reset button. A galvanic
parallel connection of several test or reset inputs for testing multiple insulation moni-
toring devices is not allowed.
3.2.2.6 Fault memory
The fault memory can be activated or deactivated with the parameter "M". When the
fault memory is activated, all pending relay alarm messages remain available until they
are deleted using the reset button (internal/external), or the supply voltage Usis turned
off.
The stop function can also be triggered via an interface command and in
this case it can only be reset via the interface.

Function
19
isoHV525_D00297_05_M_XXEN/08.2019
3.2.2.7 Interface/protocols
The ISOMETER® uses the serial hardware interface RS-485 with the following protocols:
BMS
The BMS protocol is an essential component of the Bender measuring device interface
(BMS bus protocol). ASCII characters are used in the data transfer.
Modbus RTU
Modbus RTU is an application layer messaging protocol and it provides Master/Slave
communication between devices that are connected altogether via bus systems and
networks. Modbus RTU messages have a 16-bit CRC (Cyclic Redundant Checksum),
which guarantees reliability.
IsoData
The ISOMETER® continuously sends an ASCII data string with a cycle of approximately
1 s. Communication with the ISOMETER® within this mode is not possible and no addi-
tional transmitter may be connected to the RS-485 bus cable. The ASCII data string for
the ISOMETER® is described on Page 43.
The isoHV525-S4-4 ISOMETER® uses the device name "isoHV425" when it
reports on the BMS bus.
The isoHV525-S4-4 ISOMETER® uses the device name "isoHV425-D4-4"
when it reports on Modbus.
The IsoData protocol can only be terminated by sending the command
"Adr3" during an interval of the isoHV525-S4-4 ISOMETER®.

Function
20 isoHV525_D00297_05_M_XXEN/08.2019
The parameter address, baud rate and parity for the interface protocols are configured
via the RS-485 interface.
With "Adr = 0", the IsoData protocol is activated. The parameter value "---"
for the baud rate indicates the activated BMS protocol. In this case, the baud
rate for the BMS protocol is set to 9,600 baud. If the baud rate is set unequal
to "---", the Modbus protocol with configurable baud rate is activated.