GESTRA NRG 26-61 User manual

Original Installation &
Operating Manual
EN
English
Level Electrode
NRG 26-61
819874-00

2NRG 26-61 - Installation & Operating Manual - 819874-00
Contents
Content of this Manual................................................................................................................................... 4
Scope of delivery/Product package............................................................................................................... 4
How to use this Manual.................................................................................................................................. 5
Illustrations and symbols used...................................................................................................................... 5
Hazard symbols in this Manual...................................................................................................................... 5
Types of warning ............................................................................................................................................ 6
Specialist terms/Abbreviations...................................................................................................................... 7
Usage for the intended purpose..................................................................................................................... 8
Applicable directives and standards...........................................................................................................9
Admissible system components, dependent on the required safety level..................................................10
Improper use ................................................................................................................................................ 11
Basic safety notes ........................................................................................................................................ 12
Required personnel qualifications............................................................................................................... 13
Notes on product liability............................................................................................................................. 13
Functional safety, safety integrity level (SIL) .............................................................................................. 14
Check the safety function regularly..........................................................................................................14
Reliability data to EN 61508 ......................................................................................................................... 15
Function ........................................................................................................................................................ 16
Technical data .............................................................................................................................................. 19
Name plate/Identification ............................................................................................................................ 21
Factory settings............................................................................................................................................ 22
Overall view of the NRG 26-61 ..................................................................................................................... 23
Dimensions of the NRG 26-61 ...................................................................................................................... 24
Preparing for installation ............................................................................................................................. 25
Installation.................................................................................................................................................... 26
Sealing surface dimensions for NRG 26-61.............................................................................................. 27
Example ..................................................................................................................................................27
Installing two level electrodes in a flange................................................................................................. 28
Installation examples with dimensions....................................................................................................... 29
Aligning the terminal box............................................................................................................................. 34
Functional elements..................................................................................................................................... 35
Connecting the CAN bus system.................................................................................................................. 36
Bus line, cable length and cross-section .................................................................................................. 36
Example ..................................................................................................................................................36
Important notes on connecting the CAN bus system................................................................................. 37
Pin assignment of the CAN bus connector and coupling for non pre-wired
control cables..........................................................................................................................................37

3NRG 26-61 - Installation & Operating Manual - 819874-00
Contents
Bringing into service .................................................................................................................................... 38
Changing the factory settings if necessary............................................................................................... 38
Notes on changing communication parameters “bd.rt, Id.Lo; Id.Hi or GrP”................................................40
Changing the “Id.Lo / Id.Hi” limiter ID.......................................................................................................41
Changing the controller group “GrP”........................................................................................................ 41
Changing the baud rate “bd.rt”................................................................................................................ 41
Setting the “AL.Lo” (low-level alarm = LW) limit....................................................................................... 42
Setting the “AL.Hi” (high-level alarm = HW) limit .....................................................................................42
Calibration to the lower bound of the active measuring range “CAL.L” (0 % calibration value) ..................43
Independent rapid calibration at a water level of > 25 % of the active measuring range “CAL.P”............. 43
Calibration to the upper bound of the active measuring range “CAL.H” (100% calibration value).............44
Setting the filter constant “Filt”................................................................................................................44
Manually initiating a display test.............................................................................................................. 45
Activating URB 2 compatibility “ConP”..................................................................................................... 45
Checking the level display by raising or reducing the level....................................................................... 46
Checking the limiter switchpoints by initiating a test function ..................................................................46
Lockout function...................................................................................................................................... 46
Starting, operation and testing .................................................................................................................... 47
System malfunctions.................................................................................................................................... 51
Causes ....................................................................................................................................................51
Indication of system malfunctions using fault codes................................................................................. 52
Common application and usage errors.....................................................................................................54
Checking installation and function ...........................................................................................................56
Taking out of service.................................................................................................................................... 57
Cleaning the level electrode......................................................................................................................... 58
Cleaning interval...................................................................................................................................... 58
Disposal ........................................................................................................................................................ 58
Returning decontaminated equipment........................................................................................................ 58
EU Declaration of Conformity....................................................................................................................... 59

4NRG 26-61 - Installation & Operating Manual - 819874-00
Content of this Manual
Product:
Level Electrode NRG 26-61
First edition:
BAN 819874-00/08-2019cm
© Copyright
All rights reserved. Any misuse, particularly reproduction and dissemination to third parties, is not permit-
ted. The General Terms & Conditions of GESTRA AG apply.
Scope of delivery/Product package
 1 x level electrode NRG 26-61
 1 x sealing ring D 27 x 32, form D, DIN 7603-2.4068, bright annealed
 1 x Installation & Operating Manual

5NRG 26-61 - Installation & Operating Manual - 819874-00
How to use this Manual
This Installation & Operating Manual describes the correct use of the NRG 26-61 level electrode.
It applies to persons who integrate this equipment in control systems, install, bring into service, operate,
maintain and dispose of this equipment. Anyone carrying out the above-mentioned activities must have
read this Installation & Operating Manual and understood its contents.
 Read this Manual in full and follow all instructions.
 Please also read the instructions for use of any accessories.
 The Installation & Operating Manual is part of the product package. Keep it in an easily accessible
location.
Availability of this Installation & Operating Manual
 Make sure this Installation & Operating Manual is always available to the operator.
 If you pass on or sell the equipment to a third party, please also hand over the Installation & Operating
Manual.
Hazard symbols in this Manual
Danger zone/Dangerous situation
Illustrations and symbols used
1. Action to be taken
2.
 Lists
 Bullet points in lists
A Keys to illustrations
Additional
information
Read the relevant
Installation & Operating Manual

6NRG 26-61 - Installation & Operating Manual - 819874-00
Types of warning
DANGER
Warning of a dangerous situation that results in death or serious injury.
WARNING
Warning of a dangerous situation that may possibly result in death or serious injury.
CAUTION
Warning of a situation that may result in minor or moderate injury.
ATTENTION
Warning of a situation that results in damage to property or the environment.

7NRG 26-61 - Installation & Operating Manual - 819874-00
Specialist terms/Abbreviations
Here, we explain some abbreviations, specialist terms, etc., which are used in this Manual.
IEC 61508
International standard IEC 61508 describes both the type of risk assessment and actions taken to provide
appropriate safety functions.
SIL (safety integrity level)
Safety integrity levels SIL 1 to 4 are used to quantify risk reduction. SIL 4 is the highest level of risk
reduction. International standard IEC 61508 forms the basis for establishing, testing and operating
technical safety systems.
CAN (Controller Area Network) bus
Data transmission standard and interface for connecting electronic equipment, sensors and control
systems. Data can be sent and received.
NRG .. / URS .. / URB .. / SRL .. / etc.
Equipment and type designations of GESTRA AG, see page 10.
SELV
Safety Extra Low Voltage
Operating point (of the plant)
The operating point describes the operating parameters within which a plant or boiler is operated in its
nominal range. In a pressurised steam plant, for example, these parameters would be output, pressure
and temperature.
The design data may be a lot more stringent, however.
A boiler that is operated at 10 bar and 180°C may be designed for a pressure of 60 bar and a
temperature of 275 °C, for example, which is not necessarily its operating point.

8NRG 26-61 - Installation & Operating Manual - 819874-00
Usage for the intended purpose
Use as a safety high-level (HW) limiter and low-level (LW) limiter
The NRG 26-61 level electrode is used in conjunction with the URS 60 / URS 61 safety control unit as a
safety high-level limiter and low-level limiter for pressurised steam and hot-water plants.
 Safety high-level limiters prevent the defined maximum high water (HW) level from being exceeded,
e.g. by switching off the feedwater supply.
 Low-level limiters react when the water drops below the set minimum level (LW), e.g. by
switching off the heating.
Safety notes for use as an LW limiter
 Since the electrode measures continuously using capacitance, the low-level limiter function
of the NRG 26-61 may only be used in combination with a conductive NRG 16-60 level
electrode.
 Always use the NRG 16-60 level electrode as the first low-level electrode.
Additional use as a level control system
In addition, the NRG 26-61 level electrode can be used with an NRR 2-60 / NRR 2-61 level controller for
continuously measuring the water level in pressurised steam and hot-water plants or in condensate and
feedwater tanks.
 In combination with the NRR 2-60 / NRR 2-61 level controller, the electrode can be used as a level
control system with MIN/MAX alarm, for example.
 The limiter functions can be disabled independently and by an infinitely variable measurement signal.
Influences of the test fluid
 The NRG 26-61 level electrode can be used in fluids with different conductivity. However, a con-
ductivity of less than 100 μS/cm has a major influence on the measured capacitance, which is why
recalibration of the measuring range (see page 43) at the operating point* and after a cold start is
extremely important.
* Operating point of the plant, see page 7.
 To achieve the best possible reproducibility and maintain high-quality measurements (see “Technical
data” on page 19), the sensor must be installed in a protective tube (see “Installation examples with
dimensions” on page 29 ff.).
 This is the only way to ensure safe use as a level limiter with a SIL 2 rating at the stated values.
 If the dielectric constant of the test fluid differs considerably from that of the usual water used
(Er = 80), it may be necessary to adjust the measuring frequency. For this, please contact the GESTRA
AG Service department.
Visual display and operation
 Viewing and operation take place using the URB 60 or SPECTOR
control operating terminal.

9NRG 26-61 - Installation & Operating Manual - 819874-00
Usage for the intended purpose
Applicable directives and standards
The NRG 26-61 level electrode has been tested and approved for use in the scope governed by the
following directives and standards:
Directives:
 Directive 2014/68/EU EU Pressure Equipment Directive
 Directive 2014/35/EU Low Voltage Directive
 Directive 2014/30/EU EMC Directive
 Directive 2011/65/EU RoHS II Directive
Standards:
 EN 12953-09 Shell boilers, requirements for limiting devices
 EN 12952-11 Water-tube boilers, requirements for limiting devices
 EN 60730-1 Automatic electrical controls – Part 1:
General requirements
 EN 61508 Functional safety of electronic systems
Standards documents:
 VdTÜV Bulletin BP WASS 0100-RL
Requirements for water level control and limiting equipment

10 NRG 26-61 - Installation & Operating Manual - 819874-00
Usage for the intended purpose
Admissible system components, dependent on the required safety level
In accordance with EU Pressure Equipment Directive 2014/68/EU and standards EN12952, EN12953
and EN61508, and the technical rules of VdTÜV Bulletin BP WASS 0100-RL, the level electrode can be
operated with the following system components, as suitable for the required safety integrity level.
Level control and
limiter electrode
Safety control
unit for limiters
Control unit as
level controller and
limit indicator
Operating unit
SIL 2
to
EN 61508
NRG 26-61 URS 60
URS 61 –URB 60,
SPECTOR
control
Without
SIL as per EN
61508
NRG 26-61 – NRR 2-60
NRR 2-61
URB 60,
SPECTOR
control
Fig. 1
Key to Fig. 1:
NRG = level electrode
URS = SPECTOR
connect safety control unit
URB = visual display and operating unit
SRL = monitoring unit
NRR = level controller, continuous
To ensure the proper use of equipment during all types of use, please also read the Installation
& Operating Manuals for the system components used.
 You will find the latest Installation & Operating Manuals for the system components named
in Fig. 1 on our website:
http://www.gestra.com/documents/brochures.html