Bender ISOMETER isoHV525 User manual

EN
Manual
Insulating monitoring device for
unearthed AC, AC/DC, and DC systems (IT systems) up to
3(N)AC, AC/DC 0...1000V or DC 0...1000 V
Software versions: D0500 V1.xx
D0453 V1.xx
ISOMETER® isoHV525
isoHV525_D00297_00_M_XXEN/03.2017

Bender GmbH & Co. KG
Postbox 1161 • 35301 Grünberg • Germany
Londorfer Straße 65 • 35305 Grünberg • Germany
Tel.: [phone]
Fax: [phone]
E-Mail: [email protected]
Web: www.bender.de
© Bender GmbH & Co. KG
All rights reserved.
Reproduction only with permission
of the publisher.
Subject to change.
Customer service
Service Hotline: 0700-BenderHelp (Tel. and Fax)
Carl-Benz-Straße 8 • 35305 Grünberg • Germany
Tel.: [phone]
Fax: [phone]
E-Mail:[email protected]
PLEASE READ THIS MANUAL AND ANY ACCOMPANYING DOCUMENTS CAREFULLY
AND KEEP THEM IN A SECURE PLACE FOR FUTURE REFERENCE.

Inhaltsverzeichnis
3isoHV525_D00297_00_M_XXEN/03.2017
1. Important information .................................................................... 5
1.1 How to use this manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.2 Technical support: Service and support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.2.1 First level support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.2.2 Repair service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.2.3 Field service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.3 Training courses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.4 Delivery conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.5 Inspection, transport and storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.6 Warranty and liability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.7 Disposal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2. Safety instructions ............................................................................ 7
2.1 General safety instructions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.2 Work activities on electrical installations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.3 Intended use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3. Function ............................................................................................. 8
3.1 isoHV525-M4-4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.1.1 Device features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.1.2 Function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.1.2.1 Manual self test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.1.2.2 Malfunction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.1.2.3 Signalling assignment of the alarm relays K1/K2 . . . . . . . . . . . 8
3.1.2.4 Measuring and response times . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.1.2.5 Operating time tae . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.1.2.6 External, combined test or reset button T/R . . . . . . . . . . . . . . . . 8
3.1.2.7 Analogue output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.2 isoHV525-S4-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.2.1 Device features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.2.2 Function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.2.2.1 Manual self test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
3.2.2.2 Malfunction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
3.2.2.3 Signalling assignment of the alarm relays K1/K2 . . . . . . . . . . .10
3.2.2.4 Measuring and response times . . . . . . . . . . . . . . . . . . . . . . . . . . .10
3.2.2.5 External, combined test or reset button T/R . . . . . . . . . . . . . . .11
3.2.2.6 Fault memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
3.2.2.7 Interface/protocols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
4. Installation, connection and commissioning ............................12
4.1 Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
4.2 Connection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
4.3 Commissioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
5. isoHV525-S4-4 parameter overview ...........................................15
5.1 Monitoring - response value . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
5.2 Configuration of the relay operating mode . . . . . . . . . . . . . . . . . . . . . . . . .15
5.2.1 Alarm assignment of relay "r1" and "r2" . . . . . . . . . . . . . . . . . . . . . . . . .15
5.2.2 Fault memory configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
5.3 Time configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
5.4 Function configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
5.5 Interface configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
5.6 Measured value description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
6. Data access to the isoHV525-S4-4 using the BMS Protocol ....17

Inhaltsverzeichnis
4isoHV525_D00297_00_M_XXEN/03.2017
7. Data access to the isoHV525-S4-4 using the
Modbus RTU Protocol .................................................................... 18
7.1 Reading out the Modbus register from the ISOMETER®. . . . . . . . . . . . . . 18
7.1.1 Master device sends a command to the ISOMETER® . . . . . . . . . . . . 18
7.1.2 The ISOMETER® answers the Master . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
7.2 Writing to the Modbus register (parameter setting) . . . . . . . . . . . . . . . . . 18
7.2.1 Master device sends a command to the ISOMETER® . . . . . . . . . . . . 18
7.2.2 The ISOMETER® answers the Master . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
7.3 Exception code. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
7.3.1 Structure of the exception code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
8. Modbus register assignment of the ISOMETER® ...................... 20
8.1 Device-specific data type of the ISOMETER® . . . . . . . . . . . . . . . . . . . . . . . . 22
8.1.1 Device name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
8.1.2 Measured values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
8.1.2.1 Float = Floating point value of the channels . . . . . . . . . . . . . . 22
8.1.2.2 AT&T = Alarm type and test type (internal/external) . . . . . . . 22
8.1.2.3 R&U = Range and unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
8.1.3 Alarm assignment of the relays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
8.2 Channel descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
9. IsoData data string ......................................................................... 25
10. Technical data ............................................................................... 26
10.1 Tabular representation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
10.2 Standards, approvals and certifications . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
10.3 Ordering information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
INDEX ..................................................................................................... 29

isoHV525_D00297_00_M_XXEN/03.2017
5
Important information
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 manual, we
have used symbols to identify important instructions and information. The meaning of
these symbols is explained below:
This signal word indicates that there is a high risk of danger that
will result in death or serious injury if not avoided.
This signal word indicates a medium risk of danger that can lead
to death or seriousinjury if not avoided.
This signal word indicates a low level risk that can result in minor
or moderate injury or damage to property if not avoided.
This symbol denotes information intended to assist the user in
making optimum use of the product.
This manual is intended for qualified personnel working in electri-
cal engineering and electronics!
DANGER
WARNING
CAUTION
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
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 replacement
device at no extra cost
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]*
Fax: [phone]
In Germany only: 0700BenderHelp (Tel. and Fax)
E-mail: [email protected]
Telephone: [phone]** (technical issues)
[phone]**, -785** (sales)
Fax: [phone]
E-mail: [email protected]

Important informationImportant information
isoHV525_D00297_00_M_XXEN/03.2017
6
*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
Änderung der Allgemeinen Lieferbedingungen für Erzeugnisse und Leistungen der Ele-
ktroindustrie" (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.
Sale 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 en-
sured.
Telephone: [phone]**, -762 **(technical issues)
[phone]** (sales)
Fax: [phone]
E-mail: [email protected]
Internet: www.bender.de
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
personnel working on the device. Furthermore, the rules and regulations that apply
for accident 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 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 disposed of properly.
For more information on the disposal of Bender devices, refer to our homepage at
www.bender.de -> Service & support.
.

isoHV525_D00297_00_M_XXEN/03.2017
7
Safety instructions
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 stand-
ards and regulations must be complied with. The European standard EN 50110 can be
used as a guide.
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 in-
stallation has been de-energised. Observe the rules for working on
electrical installations.
DANGER
2.3 Intended use
The isoHV425 ISOMETER® monitors the insulation resistance of unearthed AC, AC/DC and
DC systems (IT systems) with nominal system voltages of 3(N)AC, AC/DC 0 … 1000 V or
DC 0 …1000 V. The maximum permissible system leakage capacitance Ceis 150 µF. DC
components existing in AC systems do not influence the operating characteristics, when
a minimum load current of DC 100 mA flows. A separate supply voltage allows de-ener-
gised 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 analog output
• isoHV425-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 re-
sistance
≤ 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.

isoHV525_D00297_00_M_XXEN/03.2017
8
Function
3. Function
3.1 isoHV525-M4-4
3.1.1 Device features
• Monitoring the insulation resistance for unearthed AC/DC systems
• Automatic adaptation to the system leakage capacitance up to 150 F
• Two separate response values for Alarm 1 and Alarm 2
• Alarms are signalled via alarm relays (K1, K2)
• 0. . . 10 V analog output (galvanically separated)
3.1.2 Function description
The ISOMETER® measures the insulation resistance RFand the leakage capacitance Cebe-
tween the system to be monitored (L1/+, L2/-) and earth (PE).
If the value RFexceeds 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 but-
ton. 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 errors.
After eliminating the fault, the alarm relays are automatically reset or are reset to the ini-
tial position by pressing the Test/Reset button. The self test can take a few minutes.
The isoHV525 determines the leakage capacitance via an impedance
measurement whose frequency is adjusted to the most accurate insula-
tion measurement. The measurement signal is influenced by rectifiers or
inverters, and can lead to phase errors which in turn can lead to a
distorted leakage capacitance value.
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 restarting
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 insula-
tion resistance value is mainly determined by the required measuring pulse duration,
which depends on the insulation resistance and leakage capacitance of the system to be
monitored. The measuring pulse is produced by the measuring voltage generator, which
is integrated in the ISOMETER®. System disturbances may lead to extended measuring
times.
3.1.2.5 Operating time tae
The operating time tae is the time required by the ISOMETER® to determine the measured
value. For the measured insulation resistance value, it is dependent on the insulation re-
sistance and the leakage capacitance.
3.1.2.6 External, combined test or reset button T/R
Reset= Press the external button < 1.5 s
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 par-
allel connection of several test or reset inputs for testing multiple insulation monitoring
devices is not allowed.

FunctionFunction
isoHV525_D00297_00_M_XXEN/03.2017
9
3.1.2.7 Analogue output
The isoHV525-M4-4 ISOMETER outputs an anlaogue voltage in the range 0. . .10V.
Calculation of the insulation resistance using the analogue output:
Activation Setting value
Description
FAC
U 0 . . . 10 V 0 . . . Permissible load > 20 k
on 120 k
The scaled reference value for thr displayed
nonlinear resistance at 50% of interface con-
trol.
Variable Description
RFInsulation fault in k
RSKM Scaled reference value in k (i.e. 120 k)
A1Upper analogue value (i.e. 10 V)
A2Measured analogue output value
The analog 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)
3.2 isoHV525-S4-4
3.2.1 Device features
• Monitoring the insulation resistance for unearthed AC/DC systems
• Measurement of the mains voltage (true r.m.s.) with undervoltage and overvoltage
detection
• Measurement of DC system voltages to earth (L1+/PE and L2-/PE)
• Automatic adaptation to the system leakage capacitance up to 150 F
• 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 leakage capacitance Cebe-
tween the system to be monitored (L1/+, L2/-) and earth (PE). The r.m.s. value of the mains
voltage Unbetween L1/+ and L2/-, as well as the DC voltages between L1/+ and earth
(UL1e) and between L2/- and earth (UL2e) are also measured.
From a minimum value of the DC system voltage, the ISOMETER® determines the fault lo-
cation "R %", which shows the distribution of the insulation resistance between conduc-
tors L1/+ and L2/-.
The value range of the fault location is ±100 %:
Display Meaning
-100 % one-sided fault at conductor L2/-
0 % Symmetrical fault
+100 % one-sided fault at conductor L1/+

FunctionFunction
isoHV525_D00297_00_M_XXEN/03.2017
10
The partial resistances can be calculated from the total insulation resistance RFand the
fault location (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 mem-
ory "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 supply volt-
age is switched off. The device function can be tested using the Test/Reset button. Device
parameters are initially assigned by Bender. Parameterisation of the ISOMETER

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 ex-
ternal 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 errors.
After eliminating the fault, the alarm relays are automatically reset or are reset to the ini-
tial position by pressing the Test/Reset button. The self test can take a few minutes.
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 restarting
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 as-
signed to relay 2 (K2).
The isoHV525 determines the leakage capacitance via an impedance
measurement whose frequency is adjusted to the most accurate insula-
tion measurement. The measurement signal is influenced by rectifiers or
inverters, and can lead to phase errors which in turn can lead to
a distorted leakage capacitance value.
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 insula-
tion resistance value is mainly determined by the required measuring pulse duration,
which depends on the insulation resistance and leakage capacitance of the system to be
monitored. Measuring pulse is produced by the measuring pulse generator 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 system
voltage measurement Un is independent and considerably shorter.
Total response time tan
The total response time tan is the sum of the operating time tae and the response delay
time ton.
Operating time tae
The operating time tae is the time required by the ISOMETER® to determine the measured
value. For the measured insulation resistance value, it is dependent on the insulation re-
sistance and the leakage capacitance.
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 measuring
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.
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 respective meas-
ured value is not exceeded (including hysteresis) for the period of toff without interrup-
tion. Each time the threshold value is not exceeded for the period of toff, the delay 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.

FunctionFunction
isoHV525_D00297_00_M_XXEN/03.2017
11
3.2.2.5 External, combined test or reset button T/R
Reset= Press the external button < 1.5 s
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 par-
allel connection of several test or reset inputs for testing multiple insulation monitoring
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 de-
leted using the reset button (internal/external), or the supply voltage Usis turned off.
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 inter-
face (BMS bus protocol). ASCII characters are used in the data transfer.
The stop function can also be triggered via an interface command and
in this case it can only be reset via the interface.
The isoHV525-S4-4 ISOMETER® uses the device name
"isoHV425" when it reports on the BMS bus.
• 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 approximate-
ly 1 second. Communication with the ISOMETER® within this mode is not possible
and no additional transmitter may be connected to the RS-485 bus cable. The ASCII
data string for the ISOMETER® is described on Page 25.
The parameter address, baud rate and parity for the interface protocols are configured via
the RS-485 interface.
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®.
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 9600 baud. If the baud rate is set unequal to "---", the Modbus
protocol with configurable baud rate is activated.

isoHV525_D00297_00_M_XXEN/03.2017
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Installation, connection and commissioning
4. Installation, connection and commissioning
4.1 Mounting
Screw fixing:
Fix the device with four (4) M4 screws; see the following sketch.
Only skilled persons 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 in-
stallation has been de-energised. Observe the rules for working on
electrical installations.
If the ISOMETER® is used in rail vehicles, it must be ensured that the
ISOMETER® is installed within a control cabinet that complies with
the fire protection requirements of the DIN EN 45545-2.
DANGER
Dimension diagram and sketches for screw mounting:
4.2 Connection
Wires 1 and 2 (corresponding to A1 und A2) have to be connected to the supply voltage
according to IEC 60364-4-43, which means, the connections have to be protected against
short circuit by means of a protective device (a 6 A fuse is recommended). Concerning the
connection of terminals L1/+ and L2/- to the IT system to be monitored, devices for pro-
tection against a short circuit in accordance with IEC 60364-4-43 can be omitted if the wir-
ing is carried out in such a way as to reduce the risk of a short circuit to a minimum.
Only one ISOMETER® may be controlled via an external Test/Reset button. It is not al-
lowed to use a parallel connection of several test or reset inputs for combined testing of
ISOMETER®s.
For UL applications:
Use 60/70°C copper lines only! UL and CSA applications require the supply voltage to be
protected via 5 A fuses.
70 mm
80 mm
96 mm
70 mm
60 mm
12.5
mm 23.5 mm
50 mm 10
mm
L2/- L1/+
Signal cables
(Wires 1-11)
Side view
Front view
Bottom view

Installation, connection and commissioningInstallation, connection and commissioning
isoHV525_D00297_00_M_XXEN/03.2017
13
isoHV525-M4-4 - Connect the device as is shown in the wiring diagram
The lower temperature range applies only when the cable is firmly laid or
installed.
US
L2/- (Blue)
5 (KE) 1 (A1) 2 (A2)
Test / Reset
10 (14) 11 (24) 9 (11)
K1 K2
6 (T/R)
L1/+ (Red)
L1/+
L2/-
PE
L3
7 (M-) 8 (M+)
0. . .10 V
4 (E)
3 (E)
V
L2/- L1/+
Signal cables
(Wires 1-11)
isoHV525
1
2
3
4
5
6
7
8
9
10
11
For details about the conductor cross sections required for wiring, refer to the technical
data from Page 26.
Legend to isoHV252-M4-4 wiring diagram:
Wire
number Terminal Connections
1
2
A1
A2
Connection to the supply voltage via fuses (line protection).
If supplied from an IT system, both lines have to be protected by a
fuse
3 and 4
5
E
KE Connect each terminal separately to PE
6T/RConnection for the external combined Test/Reset button
9
10
11
11
14
24
Common connection for K1 and K2
Connection to alarm relay K1
Connection to alarm relay K2
7
8
M-
M+ Analogue communication interface
Red
Blue
L1/+
L2/– Connection to the IT system to be monitored

Installation, connection and commissioningInstallation, connection and commissioning
isoHV525_D00297_00_M_XXEN/03.2017
14
isoHV525-S4-4 - Connect the device as is shown in the wiring diagram:
The lower temperature range applies only when the cable is firmly laid or
installed.
US
5 (KE) 1 (A1) 2 (A2)
Test / Reset
10 (14) 11 (24) 9 (11)
K1 K2
6 (T/R)
L1/+
L2/-
PE
L3
COM465IP
RS-485
7 (A) 8 (B)
L2/- (Blue)
L1/+ (Red)
4 (E)
3 (E)
L2/- L1/+
Signal cables
(Wires 1-11)
isoHV525
1
2
3
4
5
6
7
8
9
10
11
For details about the conductor cross sections required for wiring, refer to the technical
data from Page 26.
Legend to isoHV252-S4-4 wiring diagram:
4.3 Commissioning
1. Check that the ISOMETER® is properly connected to the system to be monitored.
2. Connect the supply voltage to the ISOMETER®.
The device carries out a calibration, a self test and adjusts itself to the IT system to be
monitored. When high system leakage capacitances are involved, this procedure
may take up to 4 minutes.
3. Start a manual self test by pressing the Test/Reset button. Relay 1 (K1) is switched
during the self test.
4. Check the function using a genuine insulation fault.
Check the ISOMETER® in the system being monitored against earth by using a suita-
ble resistance, for example.
Wire
number Terminal Connections
1
2
A1
A2
Connection to the supply voltage via fuses (line protection).
If supplied from an IT system, both lines have to be protected by a
fuse
3 and 4
5
E
KE Connect each terminal separately to PE
6T/RConnection for the external combined Test/Reset button
9
10
11
11
14
24
Common connection for K1 and K2
Connection to alarm relay K1
Connection to alarm relay K2
7
8
A
B
Serial communications interface
Example: Connection of a BMS Ethernet gateway COM465IP
Red
Blue
L1/+
L2/– Connection to the IT system to be monitored

isoHV525-S4-4 parameter overviewisoHV525-S4-4 parameter overview
isoHV525_D00297_00_M_XXEN/03.2017
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5. isoHV525-S4-4 parameter overview
5.1 Monitoring - response value
R1 and R2 are the two parameters that monitor the insulation resistance.The value R1 can
only be set higher than the value R2. If the insulation resistance RFreaches or falls below
the activated values R1 or R2, this leads to an alarm message. If RFexceeds the values R1
or R2 plus the hysteresis value (see table below), the alarm will be cleared.
The parameters U < and U > can be activated or deactivated to monitor the mains volt-
age. The maximum undervoltage value is limited by the overvoltage value.
FAC = Factory settings
5.2 Configuration of the relay operating mode
FAC = Factory settings; Cs = Customer settings
<
Activation Setting value
Description
Available
FAC Value range FAC Cs BMS Modbus
R2 … 500 50 k kΩ Pre-alarm value Ran1
Hys. = 25% / min. 1k X X
10… R1 25 k kΩ Alarm value Ran2
Hys. = 25% / min. 1k X X
off 30 … "U>" 30 V V
Alarm value
Undervoltage r.m.s
Hys. = 5% / min. 5 V
X X
off "U<" … 1.10 k 1100 V V
Alarm value
Overvoltage r.m.s
Hys. = 5% / min. 5 V
X X
Relay K1 Relay K2
Description
Available
FAC Cs FAC Cs BMS Modbus
n.c. n.c. Operating mode of the relay n.c/
n.o. X X
5.2.1 Alarm assignment of relay "r1" and "r2"
In the alarm assignment, each notification/alarm is assigned to the corresponding relay
with the setting "on". In the event of an unsymmetrical insulation fault, only the alarm
corresponding to the assigned and affect ed conductor (L1/+ or L2/-) will be set.
FAC = Factory settings; Cs = Customer settings
* Value can be read only. Assigning a new value is not possible.
5.2.2 Fault memory configuration
FAC = Factory settings; Cs = Customer settings
K1 "r1" K2 "r2"
Alarm description
Available
FAC Cs FAC Cs BMS Modbus
off on Device error E.xx X* X
on off Pre-alarm R1
Fault RF at L1/+ X* X
on off Pre-alarm R1
Fault RF at L2/- X* X
off on Alarm R2
Fault RF at L1/+ X* X
off on Alarm R2
Fault RF at L2/- X* X
off on Alarm Un
Undervoltage X* X
off on Alarm Un
Overvoltage X* X
on off Manually started device test X
off off Device start with alarm X
FAC Cs Description
Available
BMS Modbus
off Memory function for alarm
messages (fault memory) X X

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5.3 Time configuration
FAC = Factory settings; Cs = Customer settings
5.4 Function configuration
FAC = Factory settings; Cs = Customer settings
Setting value Description Available
Value
range FAC Cs BMS Modbus
0 … 10 0 sStart-up time "t" when starting the
device X X
0 … 99 0 sResponse delay"ton" for K1 and K2 X X
0 … 99 0 sDelay on release "toff" for K1 and K2 X X
OFF / 1 / 24 24 h Repetition time device test X X
Activation Setting value
Description
Available
FAC Cs Value
range FAC Cs BMS Modbus
on Test of the system connec-
tion during device test X X
on Device test during device
start X
5.5 Interface configuration
FAC = Factory settings; Cs = Customer settings;
( ) = User setting that is not modified by FAC.
Setting value
Description
Available
Value range FAC Cs BMS Modbus
0 / 3 … 90 3 ( ) BusAdr.
Adr = 0 deactivates BMS as well as
Modbus and activates isoData with
continuous data output
(115k2, 8E1)
X X
--- /
1.2k … 115k “---“ ( ) Baud rate
“---“ --> BMS-Bus (9k6, 7E1)
"1.2k" … "115k" --> Modbus (variable,
variable)
X X
8E1
8o1
8n1
8E1 ( )
Modbus
8E1 - 8 Data bits
even Parity, 1 Stop bit
8o1 - 8 data bits
odd parity, 1 stop bit
8n1 - 8 data bits
no parity, 1 stop bit
X

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5.6 Measured value description
Description
Insulation resistance RF
1 k ... 4 M Resolution 1 k
Leakage capacitance Ce
1 F ... 200 F Resolution 1 F
Mains voltage L1 - L2 Un
0 VRMS … 1.15 kVRMS Resolution 1 VRMS
Mains voltage L1/+ - PE UL1e
0 VDC … 1.15 kVDC Resolution 1 VDC
Mains voltage L2/- - PE UL2e
0 VDC … 1.15 kVDC Resolution 1 VDC
Fault location in %
-100 % …+100 %
Insulation resistance RUGe
1 k ... 4 M Resolution 1 k
6. Data access to the isoHV525-S4-4 using the BMS
Protocol
The BMS protocol is an essential component of the Bender measuring device interface
(BMS bus protocol). ASCII characters are used in the data transfer.
BMS channel no. Operation value Alarm
1RFPre-alarm R1
2RFAlarm R2
3Ce----
4UnUndervoltage
5UnOvervoltage
6--- Connection fault earth (E.01)
7--- Connection fault system (E.02)
8--- All other device faults (E.xx)
9Fault location [%] ---
10 UL1e ---
11 UL2e ---
12 Update counter ---
13 RUGe ---
14 --- ---
15 --- ---

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isoHV525_D00297_00_M_XXEN/03.2017
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7. Data access to the isoHV525-S4-4 using the
Modbus RTU Protocol
Requests to the ISOMETER® can be made using the function code 0x03 (read multiple reg-
isters) or the command 0x10 (write multiple registers). The ISOMETER® generates a func-
tion-related answer and sends it back.
7.1 Reading out the Modbus register from the ISOMETER®
The required Words of the process image can be read out from the "Holding registers" of
the ISOMETER® using the function code 0x03. For this purpose, the start address and the
number of the registers to be read out have to be entered. Up to 125 Words (0x7D) can
be read with one single request.
7.1.1 Master device sends a command to the ISOMETER®
In the following example, the ISOMETER® master requests the content of register 1003
with address 3. The register contains the channel description of measuring channel 1.
7.1.2 The ISOMETER® answers the Master
Byte Name Example
Byte 0 ISOMETER® Modbus address 0x03
Byte 1 Function code 0x03
Byte 2, 3 Start address 0x03EB
Byte 4, 5 Number of registers 0x0001
Byte 6, 7 CRC16 Checksum 0xF598
Byte Name Example
Byte 0 ISOMETER® Modbus address 0x03
Byte 1 Function code 0x03
Byte 2 Number of data bytes 0x02
Byte 3, 4 Data 0x0047
Byte 7, 8 CRC16 Checksum 0x81B6
7.2 Writing to the Modbus register (parameter setting)
Registers in the device can be modified with the Modbus command 0x10 (set multiple
registers). Parameter registers are available from address 3000. The content of the regis-
ter is listed in the table Page 20.
7.2.1 Master device sends a command to the ISOMETER®
In this example, the master addresses the ISOMETER® with address 3 and requests that
the content of the register with address 3003 is set to 2.
7.2.2 The ISOMETER® answers the Master
Byte Name Example
Byte 0 ISOMETER® Modbus address 0x03
Byte 1 Function code 0x10
Byte 2, 3 Start register 0x0BBB
Byte 4, 5 Number of registers 0x0001
Byte 6 Number of data bytes 0x02
Byte 7, 8 Data 0x0002
Byte 9, 10 CRC16 Checksum 0x9F7A
Byte Name Example
Byte 0 ISOMETER® Modbus address 0x03
Byte 1 Function code 0x10
Byte 2, 3 Start register 0x0BBB
Byte 4, 5 Number of registers 0x0001
Byte 6, 7 CRC16 Checksum 0x722A

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7.3 Exception code
If a request cannot be answered for whatever reason, the ISOMETER® will send a so-called
exception code with which possible faults can be narrowed down.
7.3.1 Structure of the exception code
Exception code Description
0x01 Impermissible function
0x02 Impermissible data access
0x03 Impermissible data value
0x04 Internal fault
0x05 Acknowledgement of receipt (answer will be time delayed)
0x06 Request not accepted (repeat request if necessary)
Byte Name Example
Byte 0 ISOMETER® Modbus address 0x03
Byte 1 Function code (0x03) + 0x80 0x83
Byte 2 Data (exception code) 0x04
Byte 3, 4 CRC16 Checksum 0xE133

isoHV525_D00297_00_M_XXEN/03.2017
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Modbus register assignment of the ISOMETER®
8. Modbus register assignment of the ISOMETER®
Depending on the device state, the information in the registers is either the measured
value without alarm; the measured value with alarm 1; the measured value with alarm 2;
or only the device fault.
Register
Measured value
Device fault
Without alarm Alarm 1 Alarm 2
1000
to
1003
RF
Insulation fault (71)
[no alarm]
RF
Insulation fault (1)
[prewarning]
RF
Insulation fault (1)
[alarm]
---
Connection earth
(102)
[device fault]
1004
to
1007
--- --- --- ---
1008
to
1011
Un
Voltage (76)
[no alarm]
Un
Undervoltage
(77) [alarm]
Un
Overvoltage
(78) [alarm]
---
Connection to sys-
tem (101)
[device fault]
1012
to
1015
Ce
capacitance (82)
[no alarm]
--- --- ---
1016
to
1019
UL1e
Voltage (76)
[no alarm]
--- --- ---
1020
to
1023
UL2e
Voltage (76)
[no alarm]
--- --- ---
1024
to
1027
Fault location in %
--- (1022)
[no alarm]
--- --- ---
1028
to
1031
RUGe
Insulation fault (71)
[no alarm]
--- --- ---
( ) = Channel description code (refer to Chapter 8.2)
[ ] = Alarm type (refer to Chapter 8.1.2.2)
1032
to
1035
Measured value
update counter
--- (1022)
[no alarm]
--- ---
---
Device error (115)
[device fault]
Register Property Description Format Unit Value range
3000 RW Reserved --- --- ---
3001 RW Reserved --- --- ---
3002 RW Reserved --- --- ---
3003 RW Reserved --- --- ---
3004 RW Reserved --- --- ---
3005 RW
Pre-alarm value
resistance measure-
ment "R1"
UINT 16 k R2 … 500
3006 RW Reserved --- --- ---
3007 RW
Alarm value resist-
ance measurement
"R2"
UINT 16 k 10 … R1
3008 RW
Activation alarm
value undervoltage
"U<"
UINT 16 --- 0 = Inactive
1 = Active
3009 RW Alarm value under-
voltage "U<" UINT 16 V 30 … U>
3010 RW
Activation alarm
value overvoltage
"U>"
UINT 16 --- 0 = Inactive
1 = Active
3011 RW Alarm value
Overvoltage "U >" UINT 16 1/10 V U< … 1100
3012 RW
Memory function for
alarm messages
(Fault memory) "M"
UINT 16 --- 0 = Inactive
1 = Active
Register
Measured value
Device fault
Without alarm Alarm 1 Alarm 2