Bender ISOMETER isoPV1685DP User manual

Manual EN
Software version: D0650 V3.1x
ISOMETER®
isoPV1685DP
Insulation monitoring device for unearthed systems
in photovoltaic systems
isoPV1685DP_D00479_00_M_XXEN/02.2023

Bender GmbH & Co. KG
Londorfer Str. 65 • 35305 Grünberg • Deutschland
Postbox 1161 • 35301 Grünberg • Deutschland
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.
Fotos: Bender archive

Table of Contents
3
isoPV1685DP_D00479_00_M_XXEN/02.2023
Table of Contents
1. Important information .............................................................................................7
1.1 How to use this manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.2 Technical support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
1.3 Training courses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.4 Delivery conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.5 Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.6 Warranty and liability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.7 Disposal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2. Safety instructions ..................................................................................................11
2.1 General safety instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.2 Work activities on electrical installations.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.3 Device-specific safety instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.4 Intended use. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3. Function ....................................................................................................................13
3.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3.2 Product description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3.3 Functional description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
3.4 History memory. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
3.5 Self test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
4. Device overview ......................................................................................................18
4.1 Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
4.2 Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
4.3 Display and operating elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
4.4 Operating and navigating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
5. Mounting and connection .....................................................................................23
5.1 Mounting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
5.2 Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
5.3 Connection to a 3AC system with an EDS440 and and IOM441
to a 3AC system. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
6. Commissioning ........................................................................................................28
6.1 Commissioning flow chart insulation fault monitoring. . . . . . . . . . . . . . . . . . . . . . . . . . 28
6.2 Commissioning flow chart with insulation fault location . . . . . . . . . . . . . . . . . . . . . . . 29
6.3 Initial commissioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
6.4 Recommissioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
6.5 Commissioning EDS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
7. Display .......................................................................................................................34
7.1 Standard display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
7.2 Fault display (active) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
7.3 Fault display (inactive) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
7.4 Acknowledging a fault message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
7.5 History memory. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
7.6 Data-isoGraph . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
7.7 Insulation fault location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

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4isoPV1685DP_D00479_00_M_XXEN/02.2023
8. Settings ..................................................................................................................... 40
8.1 Device menu structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
8.2 Settings in the device menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
8.1 (1.0) Alarm settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
8.2 (1.1) Insulation alarm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
8.2 (1.2) Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
8.2 (1.3) Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
8.2 (1.4) Coupling monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
8.2 (1.5) Power frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
8.2 (1.6) Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
8.2 (1.7) Outputs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
8.2 (2.0) EDS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
8.2 (2.1) General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
8.2 (2.2) Scanning channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
8.2 (2.3) Activating channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
8.2 (2.4) Group settings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
8.2 (2.5) Channel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
8.2 (2.6) Outputs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
8.2 (2.7) Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
8.2 (2.8) Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
8.2 (2.9) Service. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
8.2 (3.0) Data measured values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
8.2 (4.0) Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
8.2 (5.0) History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
8.2 (6.0) Device settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
8.2 (6.1) Language . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
8.2 (6.2) Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
8.2 (6.3) Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
8.2 (6.4) Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
8.2 (6.5) Password . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
8.2 (6.6) Commissioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
8.2 (6.7) Factory settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
8.2 (6.8) Service. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
8.2 (7.0) Info . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
9. Device communication ..........................................................................................62
9.1 RS-485 interface with BMS protocol. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
9.2 RS-485 interface with Modbus protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
10. Insulation fault location .......................................................................................69
10.1 General description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
10.2 Required settings for insulation fault location. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
10.3 Indication on the display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
10.4 Starting and stopping the insulation fault location . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

Table of Contents
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isoPV1685DP_D00479_00_M_XXEN/02.2023
11. Alarm messages ....................................................................................................70
12. Technical data ........................................................................................................71
12.1 Device profiles. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
12.2 Diagrams of the leakage capacitance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
12.3 Factory settings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
12.4 Tabular data isoPV1685DP-425 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
12.5 Standards and certifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
12.6 Ordering details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
12.7 Change log . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

Important information
7
isoPV1685DP_D00479_00_M_XXEN/02.2023
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!
Read the manual before you begin to mount, connect, and
commission the unit. Always keep the manual within easy reach for
future reference following commissioning.
DANGER
This signal word indicates that there is a high risk of danger that will
result in electrocution 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.
This symbol denotes information intended to assist the user in
making optimum use of the product.

Important information
8isoPV1685DP_D00479_00_M_XXEN/02.2023
1.2 Technical support
1.2.1 End customer support and advice
Technical support by phone or e-mail for all Bender products
• Questions concerning specific customer applications
• Commissioning
• Troubleshooting
Telephone: [phone] (365 days from 07:00 - 20:00 Uhr [MEZ/UTC +1])
Fax: [phone]
0700BenderHelp (Tel. and Fax in Germany only)
E-mail: [email protected]
1.2.2 Repair
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
• Extended guarantee, in-house repair service, replacement devices at no extra cost
Telephone: [phone]* (technical issues)
[phone]*, -785* (sales)
Fax: [phone]
E-mail: [email protected]
Please send the devices for repair to the following address:
Bender GmbH, Repair-Service,
Londorfer Strasse 65,
35305 Grünberg
1.2.3 Customer service
On-site service for all Bender products
• Commissioning, parameter setting, maintenance, troubleshooting
• 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: [e-mail]
Internet: www.bender.de
* Mo-Thu 07:00 a.m. - 16:00 p.m. , Fr 07:00 a.m. - 13:00 p.m.

Important information
9
isoPV1685DP_D00479_00_M_XXEN/02.2023
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 Er-
zeugnisse 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 industry) set out by the ZVEI (Zentral-
verband Elektrotechnik- und Elektronikindustrie e.V.) (German Electrical and Electronic Ma-
nufacturers' Association) also applies. Amending the “General Conditions for the supply of
Products and Services of the Electrical and Electronics Industry” (GL)*
Sale and delivery conditions can be obtained from Bender in printed or electronic format.
1.5 Storage
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.
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 person-
nel working on the device. Furthermore, the rules and regulations that apply for accident
prevention at the place of use must be observed.

Important information
10 isoPV1685DP_D00479_00_M_XXEN/02.2023
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 direc-
tive on the restriction of certain hazardous substances in electrical and electronic equip-
ment (RoHS directive) apply in the European Community. 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 13 August 2005 must be taken back by the
manufacturer and disposed of properly.
For more information on the disposal of Bender devices, refer to our homepage at
www.bender.de -> Service & Support.

Safety instructions
11
isoPV1685DP_D00479_00_M_XXEN/02.2023
2. Safety instructions
2.1 General safety instructions
Part of the device documentation in addition to this manual is the enclosed "Safety instruc-
tions 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.
Read the operating manual before starting to mount, connect and
com-mission the device. After successful commissioning, keep the
manual within easy reach for future reference.
Only qualified personnel 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
12 isoPV1685DP_D00479_00_M_XXEN/02.2023
2.3 Device-specific safety instructions
2.4 Intended use
The device is used for monitoring the insulation resistance in large power supply systems
designed as IT systems. Thespecific measurement method AMPPLUS monitors the insulation
resistance also in installations where extremely high system leakage capacitances to earth
exist due to interference suppression methods. Adaptation even to high leakage capacitan-
ces takes place automatically up to the respective limit of the profile.
The device generates locating current pulses required for insulation fault location. That al-
lows the localisation of the insulation fault using permanently installed or mobile insulation
fault locators.
Intended use also implies:
• The observation of all information in the operating manual
• Compliance with test intervals
In order to meet the requirements of the standards for the respective application, adapta-
tion to the system and operating conditions on site must be carried out in every case. Ob-
serve the limits of the application range specified in the technical data.
Any other use than that described in this manual is regarded as improper.
Installation inside a control cabinet
If the ISOMETER® is installed inside a control cabinet, the insulation
fault message must be audible and/or visible to attract attention.
IT systems with several ISOMETER®s
Make sure that only one active ISOMETER® is connected in each
interconnected system. If IT systems are interconnected via coupling
switches, make sure that ISOMETER®s not currently used are
disconnected from the IT system and deactivated. For IT systems
coupled via diodes or capacitances a central control of the different
ISOMETER®s is required.
Prevent measurement errors!
When a monitored IT system contains galvanically coupled DC
circuits, an insulation fault can only be detected correctly if the
rectifier valves (e.g. rectifier diode, thyristors, IGBTs, frequency
inverters, …) carry a minimum current of > 10 mA.
Unspecified frequency range
When connecting to an IT system with frequency components below
the specified frequency range, the response times and response
values may differ from the indicated technical data. However,
depending on the application and the selected measurement
method, continuous insulation monitoring is also possible in this
frequency range.

Function
13
isoPV1685DP_D00479_00_M_XXEN/02.2023
3. Function
3.1 Features
ISOMETER® for AC IT systems with galvanically connected rectifiers or inverters and for
DC IT systems. (IT = unearthed systems)
• Automatic adjustment to high system leakage capacitances, for measuring ranges
see 11. "Alarm messages" on page 70
• Combination of AMPPLUS and other profile-specific measurement method
• Separately adjustable response values Ran1 (alarm 1) and Ran2 (alarm 2) for prewar-
ning and alarm
• High-resolution graphic LC display for excellent readability and recording of the
device status
• Connection monitoring
• Automatic device self test with automatic alarm message in the event of a fault
• Graphical representation of the insulation resistance over time (isoGraph)
• History memory with real-time clock (buffer for 13 days) for storing 1023 alarm mes-
sages with date and time
• Remote setting of certain parameters via the Internet (COMTRAXX® gateway)
• Remote diagnosis by the Bender service via the Internet
• RS-485 interface for data exchange with other Bender devices
• Measurement of insulation faults 200 …1 M
• Integrated locating current injector up to 50 mA for insulation fault location
• Display of insulation faults selectively located by EDS systems
• Parameter setting of EDS systems
• Customer-specific texts for each measuring channel via the menu
3.2 Product description
ISOMETER®s of the model isoPV1685DP are used for insulation monitoring of large systems
designed as IT systems. The device variants described in the manual have different voltage
ranges. The exact device specification can be found in Chapter 12. Technical data.
The measurement method especially developed for this purpose monitors the insulation
resistance even in installations where extremely high system leakage capacitances against
earth exist due to interference suppression methods. Adaptation even to system-related
high leakage capacitances is automatic.
The ISOMETER®s isoPV1685DP generate locating current pulses required for insulation
fault location. That allows the localisation of the insulation fault using permanently ins-
talled or mobile insulation fault locators.

Function
14 isoPV1685DP_D00479_00_M_XXEN/02.2023
3.3 Functional description
Insulation monitoring is carried out using an active measuring pulse which is superimpo-
sed onto the IT system to earth via the integrated coupling. If the insulation resistance bet-
ween the IT system and earth falls below the set prewarning response value Ran1, the
"ALARM 1" LED lights up and relay K1 (11/12/14) switches. If the insulation resistance falls
below the alarm response value Ran2, alarm relay K2 (21/22/24) switches and the "ALARM
2" LED lights up.
When starting the insulation fault location, the "PGH ON" LED signals the locating current
pulse.
3.3.1 Insulation monitoring
For insulation monitoring, a pulsating AC measuring voltage is superimposed onto the IT
system. The measuring pulse consists of positive and negative rectangular impulses of the
same amplitude. The period duration depends on the system leakage capacitances in each
case and the insulation resistances of the system to be monitored.
Pulse sequence of the measuring voltage for insulation fault monitoring
An insulation fault between the IT system and earth closes the measuring circuit. If the in-
sulation resistance between system and earth falls below the set response values Ran1 and
Ran2 (response value Ran1 can be set equal or higher than Ran2), the associated alarm relays
K1 (11, 12, 14) or K2 (21, 22, 24) switch. Detected insulation faults are signalled to other bus
devices via the BMS bus. In addition, the alarm LEDs ALARM 1 or ALARM 2 light up.
3.3.2 Insulation fault location
For insulation fault location, a suitable locating current is superimposed onto the faulty IT
system with which insulation fault locators of the EDS... series can locate insulation faults.
The ISOMETER® features an internal locating current injector with ILDC 50 mA.
Pulse sequence of the internal locating current injector for insulation fault location
U
m
t
2 s 4 s 2 s 4 s
I
L
t

Function
15
isoPV1685DP_D00479_00_M_XXEN/02.2023
If the "Auto EDS function" is enabled, the ISOMETER® starts the insulation fault location after
the value has fallen below the response values Ran1 and Ran2. When starting the insulation
fault location, the "PGH ON" LED signals the locating current pulse.
During the insulation fault location process, the measurement of the insulation resistance is
deactivated and the coupling is disconnected from the mains. If during the insulation fault lo-
cation the locating current falls below the value measurable by the EDS, the insulation fault
location is terminated by the ISOMETER®.
3.3.3 Assignment of the alarm relays K1, K2, K3
K1 switches when the value falls below the alarm response value Ran1 (insulation resistance).
K2 switches when the value falls below the alarm response value Ran2 (insulation resistance).
K3 switches in the event of a device error or a connection fault.
3.3.4 Deactivating the device
When the device is deactivated, the coupling unit of the device is galvanically isolated from
the system being monitored.
The device does not measure the insulation resistance, the message "Device inactive" appears
on the display. The IT system is NOT being monitored!
The device uncouples itself from the system to be monitored through an internal system iso-
lating switch.
Activation or deactivation is done via
•adigitalinput
• the menu item Alarm settings
• the BMS bus and Modbus RTU
The standby mode of the ISOMETER®, for example, enables application in coupled systems,
since in interconnected systems only one insulation monitoring device may be connected.
3.3.5 Measured value transmission
All recorded measured values, operating messages and alarms are made available via the BMS
bus or Modbus RTU.
CAUTION
Malfunctions due to excessive locating current on sensitive system
parts! The locating current flowing between the IT system and earth can
cause controller faults in sensitive parts of the system, such as the PLC or relay.
Ensure that the level of the locating current is compatible with the system to
be monitored.

Function
16 isoPV1685DP_D00479_00_M_XXEN/02.2023
3.4 History memory
All warnings, alarms and device errors are stored in the internal history memory with date and
time stamp. The time the event started, the time of acknowledgement and the end of the
event are recorded. The history memory can be called up and reset via the device menu.
(see "History" on page 57)
3.5 Self test
3.5.1 Self test after connection to the supply voltage
Once connected to the supply voltage, all internal measurement functions, the components
of the process control such as data and parameter memory as well as the connections to earth
are checked. The self test is completed after approx. 60 s. Afterwards, the normal measure-
ment mode begins.
If a device error or a connection fault is detected, the corresponding alarm will be indicated in
the display as well as via the alarm relay K3 (31-32-34). This relay operates continuously in NC
operation, i.e. a device error is signalled even in case of a complete device failure.
During this self test, when the device is being started, the alarm relays are not switched.
3.5.2 Automatic self test
All supply voltages are continuously monitored. The following tests are continuously carried
out in the background:
•E-KEconnection
• Temperature monitoring of coupling and locating current injector
A self test is automatically run at 24-hour intervals.
During the automatic self test, the alarm relays K1 (11-12-14) and K2 (21-22-24) are not swit-
ched. K3 will not be switched either.
√
33 %
Test successful
Test not successful
Test not available
(e.g. incorrect device settings).
Test in progress
Measurement
Coupling
Earth connec-
tion
TEST

Function
17
isoPV1685DP_D00479_00_M_XXEN/02.2023
3.5.3 Manual self test
The self test is started via the TEST button of the ISOMETER®.
The following tests are only carried out in the manual self test mode:
• Internal flash
•CPUregister
•Watchdogs
•Oscillator
• Restart of the device including re-initialisation and recalibration
• Connection monitoring system
During the manual self test, all alarm relays are switched.

Device overview
18 isoPV1685DP_D00479_00_M_XXEN/02.2023
4. Device overview
4.1 Dimensions
All dimensions in mm
ISOMETER
®iso1685
246
12540,5
40,75
51
368
383
401,5
106
64
8,75
5,2
61,8
76,6
39,8
55,7

Device overview
19
isoPV1685DP_D00479_00_M_XXEN/02.2023
4.2 Connections
upper graphic
I2+,I2- / I1+, I1- digital Inputs
CAN1 / CAN2 no function
RS485 Term. off / on RS-485 termination
A, B, S RS-485 bus connection (A,B) Protocol: BMS
S= PE potential Connect one end of shield
k, I, kT, IT no function
31, 32, 34 Relay output for internal device errors (LED SERVICE)
21, 22, 24 Relay output for alarm 2 insulation faults
11, 12, 14 Relay output for alarm 1 insulation faults
E / KE Separate connection of E (earth) and KE (reference) to PE.
Connect both to PE
A1, A2 Supply voltage UsDC 24 V Arbitrary polarity
Connection via fuses, 2 A each
lower graphic
L1/+ Connection to L1/+ of the IT system via 1 A fuse
L2/- Connection to L2/- of the IT system via 1 A fuse
I2+ I2- I1+ I1-
I2+ I2- I1+ I1-
CAN 1 CAN 2 RS-485
Term .
o on A B S
A B S
k l kT IT
k I kT IT
31 32 34
K3
31 32 34
21 22 24
K2
21 22 24
11 12 14
K1
11 12 14
E K E
E KE
A1 A2
A1 A2
L2/L-
L2/-
L1/L+
L1/+

Device overview
20 isoPV1685DP_D00479_00_M_XXEN/02.2023
4.3 Display and operating elements
4.3.1 Display elements
1ON
(green) The operation indicator lights up continuously.
2The device display shows information regarding the device and the mea-
surements. For further information, refer to the chapter 7. "Display”.
3PGH ON
(yellow)
The "PGH ON" LED flashes during insulation fault location. It indicates
that the locating current for the insulation fault location is being genera-
ted. The "PGH ON" LED is only active for isoxx1685DP.
4SERVICE
(yellow)
When a device error is detected, the "SERVICE" LED lights up.
If the LED stays lit, please check the error code list on page 66.
5ALARM 1
(yellow)
Insulation fault 1 (prewarning):
The "ALARM 1" LED lights continuously if the insulation resistance falls
below the response value 1, RF < Ran1
Flashes: connection fault, check earth and system (L1/+, L2/-)
6ALARM 2
(yellow)
Insulation fault 2 (alarm):
The "ALARM 2" LED lights continuously if the insulation resistance falls
below the response value 2, RF < Ran2
Flashes: connection fault, check earth and system (L1/+, L2/-)
PGH ON
1
2
3
4
5
6
7
8
9
10
11
12