GESTRA NRG 26-60 Installation instructions

Installation & Operating Manual
EN
English
Level Electrode
NRG 26-60
819875-01

2NRG 26-60 - Installation & Operating Manual - 819875-01
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
Admissible system components................................................................................................................. 9
Improper use .................................................................................................................................................. 9
Basic safety notes ........................................................................................................................................ 10
Required personnel qualifications............................................................................................................... 11
Notes on product liability............................................................................................................................. 11
Function ........................................................................................................................................................ 12
Technical data .............................................................................................................................................. 15
Example name plate/Identification.............................................................................................................. 17
Factory settings............................................................................................................................................ 18
Overall view of the NRG 26-60 ..................................................................................................................... 19
Dimensions of the NRG 26-60 ...................................................................................................................... 20
Preparing for installation ............................................................................................................................. 21
Installation.................................................................................................................................................... 22
Sealing surface dimensions for NRG 26-60.............................................................................................. 23
Example .................................................................................................................................................. 23
Installing two level electrodes in a flange by detaching a terminal box ..................................................... 24
Installation examples with dimensions....................................................................................................... 27
Aligning the terminal box............................................................................................................................. 32
Functional elements..................................................................................................................................... 33
Connecting the CAN bus system.................................................................................................................. 34
Bus line, cable length and cross-section .................................................................................................. 34
Example .................................................................................................................................................. 34
Important notes on connecting the CAN bus system................................................................................. 35
Pin assignment of the CAN bus connector and coupling for non pre-wired control cables......................... 35

3NRG 26-60 - Installation & Operating Manual - 819875-01
Contents
Bringing into service .................................................................................................................................... 36
Changing the factory settings if necessary............................................................................................... 36
Changing parameters with password protection enabled ......................................................................... 36
Notes on changing the communication parameter “GrP or bd.rt”.............................................................. 39
Changing the controller group “GrP” ........................................................................................................ 39
Changing the baud rate “bd.rt”................................................................................................................ 40
Calibrating the lower limit of the active measuring range “CAL.L” (0% calibration value).......................... 40
Independent rapid calibration at a water level of > 25% of the active measuring range “CAL.P”.............. 41
Calibrating the upper limit of the active measuring range “CAL.H” (100% calibration value)..................... 41
Setting the filter constant “Filt”................................................................................................................ 41
Manually initiating a display test .............................................................................................................. 42
Activating URB 2 compatibility “ConP”..................................................................................................... 42
Viewing the software version and equipment type “Info”.......................................................................... 42
Enabling/disabling password protection ................................................................................................... 43
Check the MIN and MAX limit values of the NRR 2-6x level controller by raising or lowering the level ...... 44
Starting, operation and testing .................................................................................................................... 45
System malfunctions.................................................................................................................................... 47
Causes .................................................................................................................................................... 47
Indication of system malfunctions using error codes................................................................................ 48
Common application and usage errors..................................................................................................... 50
Checking installation and function ........................................................................................................... 52
Taking out of service/Disassembly.............................................................................................................. 53
Cleaning the level electrode......................................................................................................................... 54
Cleaning interval...................................................................................................................................... 54
Disposal ........................................................................................................................................................ 54
Returning decontaminated equipment........................................................................................................ 54
Declaration of Conformity; Standards and Directives................................................................................. 55

4NRG 26-60 - Installation & Operating Manual - 819875-01
Content of this Manual
Product:
Level Electrode NRG 26-60
First edition:
BAN 819875-00/08-2019cm
© 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 26-60
■ 1 x sealing ring D 27 x 32, form D, DIN 7603-2.4068, bright annealed
■ 1 x Installation & Operating Manual
Accessories
■ 1 x M12 CAN bus connector, 5-pole, A-coded, with 120 Ω terminating resistor

5NRG 26-60 - Installation & Operating Manual - 819875-01
How to use this Manual
This Installation & Operating Manual describes the correct use of the NRG 26-60 level electrode.
It applies to all persons who integrate this equipment into control systems, install, bring into service, op-
erate, 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 given.
■ 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 that the 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
Danger of death from electric shock
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
+
-
Press the rotary knob

6NRG 26-60 - Installation & Operating Manual - 819875-01
Types of warning
DANGER
Warning of a dangerous situation that will result 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 will result in damage to property or the environment.

7NRG 26-60 - Installation & Operating Manual - 819875-01
Specialist terms/Abbreviations
Here, we explain some abbreviations, specialist terms, etc., which are used in this Manual.
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 9.
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 steam boiler, for example, these parameters would be pressure and temperature.
The pressure at the operating point does not have to match the design pressure, but is the same or lower.

8NRG 26-60 - Installation & Operating Manual - 819875-01
Usage for the intended purpose
Use as a water level controller
The NRG 26-60 level electrode can be used together with an NRR 2-60/NRR 2-61 level controller to
continuously measure the water level in steam boiler and hot water installations 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.
Influence of the fluid to be monitored
■ The NRG 26-60 level electrode can be used in fluids with different conductivity. However, a conduc-
tivity of less than 100 µS/cm has a major influence on the measured capacitance, which is why it is
extremely important to recalibrate the measuring range at the operating point* when bringing into
service.
* Operating point of the plant,see page 7.
■ To achieve the best possible reproducibility and maintain high-quality measurements (see “Technical
data” on page 15), the sensor must be installed in a protective tube (see “Installation examples with
dimensions” on page 27 ff.).
■ The dielectric constant of the monitored medium may require an adjustment to the measurement
frequency if it deviates significantly from the usual water (Er = 80). Please contact GESTRA Service for
this.
Visual display and operation
■ Visual display and operation take place using the URB 60 or SPECTOR
control
operating terminal.

9NRG 26-60 - Installation & Operating Manual - 819875-01
Usage for the intended purpose
Admissible system components
The level electrode can be operated with the following system components:
Level control and
limiter electrode
Control unit as level controller
and limit indicator Operating unit
NRG 26-60 NRR 2-60
NRR 2-61
URB 60,
SPECTOR
control
Fig. 1
Key to Fig. 1:
NRG = level electrode
NRR = level controller, continuous
URB = visual display and operating unit
To ensure proper 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:
www.gestra.com
Improper use
There is a danger of death due to explosion if the equipment is used in potentially explo-
sive atmospheres.
Do not use the equipment in potentially explosive atmospheres.
Do not bring any equipment into service that does not have its own specific name plate.
The name plate indicates the technical features of the equipment.

10 NRG 26-60 - Installation & Operating Manual - 819875-01
Danger to life from scalding if the level electrode is removed under pressure. Steam or
hot water can spurt forcefully out of the equipment.
■ Only remove the level electrode at a boiler pressure of 0 bar.
Risk of severe burns if work is performed on a level electrode that has not been allowed
to cool. The level electrode becomes very hot during operation.
■ Always allow level electrodes to cool.
■ Perform all installation and maintenance work only when the level electrode has been
allowed to cool.
There is a risk of electric shock during work on electrical systems.
■ Always switch off the voltage to the plant before performing connection work.
■ Check that the plant is not carrying live voltage before commencing work.
Danger to life from a faulty NRG 26-60 level electrode due to the sudden escape of
hot steam or hot water.
Jolts and impacts during transport or installation can result in damage to or leaks in the NRG
26-60 level electrode, causing pressurised hot steam or hot water to escape through the pres-
sure relief hole.
■ To prevent damage during transport and installation, do not expose the electrode
rod to major jolts or impacts.
■ Before and after installation, check that the level electrode is completely undamaged.
■ Check that the level electrode is not leaking when bringing into service.
Attempts to repair the equipment will cause the plant to become unsafe.
■ The NRG 26-60 level electrode may only be repaired by the manufacturer, GESTRA AG.
■ Only replace faulty equipment with identical equipment from GESTRA AG.
Basic safety notes

11NRG 26-60 - Installation & Operating Manual - 819875-01
Required personnel qualifications
Activity Personnel
Integration in control system Specialist staff Plant designer
Installation/electrical
connection/bringing into service Specialist staff
The unit is an item of equipment with a
safety function (EU Pressure Equipment
Directive) and may only be installed, electri-
cally connected and brought into service by
suitable, trained staff.
Company Boiler service technician Staff trained by the plant operator.
Maintenance work Specialist staff
Maintenance and refits may only be
performed by authorised staff who have
undergone specific training.
Refits Specialist staff Persons trained by the plant operator to work
with pressure and temperature.
Fig. 2
Notes on product liability
We the manufacturer cannot accept any liability for damages resulting from improper use of the equip-
ment.

12 NRG 26-60 - Installation & Operating Manual - 819875-01
Function
The NRG 26-60 level electrode works using the capacitance measurement principle and converts
the water level information into a data telegram. The 0-100% measuring range can be scaled by modify-
ing the effective length of the electrode rod.
Automatic self-test
An automatic self-test cyclically monitors the safety and function of the level electrode and measured
value acquisition.
Faults in the electrical connection or electronic measuring equipment trigger fault indications and alarms.
The data are transferred to the NRR 2-6x level controller via an ISO 11898 CAN bus in the CANopen
protocol.
These data telegrams contain the following information:
■ Level reading as raw data
■ Level reading scaled between 0-100%, as a 16-bit data word in high resolution
■ Level reading scaled in 1% increments without decimal places
■ Status or error information
◆ Fault indications on the occurrence of faults in electronic or mechanical parts
◆ Temperature in the level electrode terminal box
Controller functions
The NRG 26-60 level electrode can be used together with an NRR 2-60/NRR 2-61 level controller as a
water level controller. The controller parameters are assigned exclusively using the URB 60 visual display
and operating unit.
The alarm limits are set using the URB 60. Please read the relevant Installation & Operating
Manual to do this. For information on how the alarm contacts function, please read the Installa-
tion & Operating Manual of the relevant NRR 2-60 or NRR 2-61 level controller.
The level electrode is installed on the inside of steam boilers, tanks and feed lines in hot water instal-
lations. A protective tube provided on site keeps it functioning reliably (see page 27 “Installation
examples”).
A capacitive NRG 26-60 level electrode can be installed in a protective tube or level pot together with an
NRG 1x-60 or NRG 1x-61 level electrode.
Operation in external level pots
If a level electrode is installed outside the boiler in a level pot that can be shut off, the connecting pipes
must be flushed regularly.
If steam pipes are ≥ 40 mm and water pipes are ≥ 100 mm, installation is regarded as internal. In this
case, upstream monitoring of flushing processes is not required.

13NRG 26-60 - Installation & Operating Manual - 819875-01
Function
Indications and signals, see page 45 / 47 *
The NRG 26-60 level electrode has a green 4-digit, 7-segment display for showing readings, status infor-
mation and error codes. The operating status is indicated by a red and green LED.
Behaviour when switched on *
The display alternately shows the software version, the type and then the scaled level reading.
Behaviour in normal operation (no alarm, no faults) *
The display shows the scaled level reading (3-digit + 1 decimal place), e.g. 050.3, and sends CAN data
telegrams with the level data to be evaluated or displayed by the bus nodes.
The scale of the 0-100% measuring range is factory-set to maximum for the electrode length
used. It is extremely important to adjust this under operating conditions when bringing into
service.
Adjusting the measuring range when bringing into service (CAL.L, CAL.P or CAL.H)
Adjust the measuring range in line with the sight glass when bringing into service, see pages
40 - 41. This is the only way to gain all the benefits of high-resolution readings in the
sight glass range.
Behaviour in the event of alarms (the level is above or below the limit) *
The scaled level reading is transferred to the NRR 2-60 or NRR 2 61 level controller via CAN data tele-
gram. Depending on how the alarm limits are set in the level controller, an alarm is generated there after
the delay time has elapsed.
Behaviour in the event of malfunctions *
An error code, e.g. E.005, is shown continuously on the display. Error codes, see page 48.
The error state is transferred to the NRR 2-60 or NRR 2-61 level controller via CAN data telegram. The
fault indication triggers an immediate alarm there. For information about how the display and contacts
work, see the “System malfunctions” section of the NRR 2-60 or NRR 2-61 Installation and Operation
Manual.
Electrode alarms and malfunctions cannot be acknowledged.
When the alarm or fault is cancelled, the message on the display also disappears.
The NRR 2-60/NRR 2-61 level controller returns to normal operation.
* The tables on pages 45 - 46 clearly show the relationship between the equipment
status, the display and the alarm LEDS.

14 NRG 26-60 - Installation & Operating Manual - 819875-01
Setting parameters and changing factory settings
If necessary, you can adapt the electrode parameters to suit on-site conditions at the plant. You can set
parameters and change factory settings using a rotary knob on the terminal box, see page 36 ff.
Function

15NRG 26-60 - Installation & Operating Manual - 819875-01
Technical data
Model and mechanical connection
■ Thread G¾ A, EN ISO 228-1, see Fig. 6
Nominal pressure rating, admissible service pressure and temperature
■ PN 40 32 bar (abs) at 238 °C
Materials
■ Terminal box: 3.2581 G AlSi12, powder-coated
■ Sheath: 1.4301 X5 CrNi 18-10
■ Electrode rod insulation: PTFE
■ Screw-in body: 1.4571, X6CrNiMoTi17-12-2
pH value
■ Maximum admissible = 10
Max. installed length at 238°C, all measurements in mm
Max. installed length: 373 477 583 688 794 899 1004
Measuring range: 300 400 500 600 700 800 900
Max. installed length: 1110 1214 1319 1423 1528 1636 2156
Measuring range: 1000 1100 1200 1300 1400 1500 2000
Do not shorten the electrode rod.
Measurement quality
The information below applies to a compensated fluid conductivity range from 0.5-10000µS/cm based
on 25°C.
■ Reading error: ±1% of set measuring range at the operating point
■ Resolution of reading on display: 0.1%
■ Resolution for internal processing: 15 bit
■ Sensitivity (minimum conductivity)
◆ Water ≥ 0.5 µS/cm (see page 8 “Influence of the fluid
to be monitored”)
Supply voltage
■ 24 V DC ±20%
Power consumption
■ Max. 7 W

16 NRG 26-60 - Installation & Operating Manual - 819875-01
Technical data
Current input
■ Max. 0.3 A
Internal fuse
■ T2A
Safety cutout at excessive temperature
■ Cutout occurs when an excessive temperature of 75 °C is measured in the electrode tip
Input/output
■ Interface for CAN bus to ISO 11898, CANopen, insulated
■ M12 CAN bus connector, 5-pole, A-coded
■ M12 CAN bus socket, 5-pole, A-coded
Indicators and controls
■ 1 x green 4-digit, 7-segment display for showing status information
■ 1 x red LED for indicating an alarm
■ 1 x green LED for indicating OK
■ 1 x rotary knob IP65 with button for menu navigation and test function
Protection class
■ III Safety Extra Low Voltage (SELV)
IP rating to EN 60529
■ IP 65
Admissible ambient conditions
■ Service temperature: 0 °C – 70 °C
■ Storage temperature: - 40 °C – 80 °C
■ Transport temperature: - 40 °C – 80 °C
■ Air humidity: 10% – 95%, non-condensing
Weight
■ Approx. 2.1 kg
Admissible installation positions
■ Vertical
■ Oblique to a maximum inclination of 45°. In this case, the length of the electrode rod is limited
to 688 mm maximum.

17NRG 26-60 - Installation & Operating Manual - 819875-01
Example name plate/Identification
The date of production (quarter and year) is stamped on the screw-in body of each level
electrode.
Fig. 3
A
A
Betriebsanleitung beachten!
See installation instruction!
Vor dem Öffnen des Deckels
Gerät freischalten!
Before removing cover
isolate from power supplies!
Tamb = °C (°F)T
bar (psi)
°C (°F)
L/H=
Pmax
Tmax
Tamb
GESTRA AG
Münchener Str.77
28215 Bremen
Made in Germany
1 Safety note
2 Equipment designation
3 Equipment function
4 Nominal pressure rating
5 Connection thread
6 Material of screw-in body
7 IP rating
8 Operating data (maximum pressure and temperature)
9 Supply voltage
0Power consumption
!Measuring range
" Actual value output
§Safety integrity level
$Type-approval number
%Conformity marking
&Disposal information
/Manufacturer
(Protection class
)Material number-serial number
1
2
3
4 5 6 7
8
9 0
!
$
&
/
)
%
(
"
§

18 NRG 26-60 - Installation & Operating Manual - 819875-01
Factory settings
The NRG 26-60 level electrode is delivered ex-works with the following settings:
Parameter Display in
menu
Parameter values
Unit
NRG 26-60
Controller group GrP 0001 - - -
Baud rate bd.rt 0050 kbit/s
Calibrate start of measuring range CAL.L variable 0%
Raw value (hex)
approx. 50 mV
on ADC
Calibrate measuring range section CAL.P variable 25% Raw value (hex)
Calibrate end of measuring range CAL.H variable 100%
Raw value (hex)
approx. 2.0 V on
ADC
Filter constant FiLt 0005 seconds
Compatibility mode ConP oFF - - -
Password PW oFF - - -
Fig. 4

19NRG 26-60 - Installation & Operating Manual - 819875-01
OK
!
+
-
Overall view of the NRG 26-60
Fig. 5
A Terminal box
B Operating panel with 4-digit LED display/alarm
LEDs and rotary knob, see page 45
C Cover screws M4 x 16 mm
D M12 CAN bus socket, 5-pole, A-coded
E M12 CAN bus connector, 5-pole, A-coded
G Seal seat for sealing ring
J Electrode
H Sealing ring D 27 x 32, form D, DIN 7603-2.4068,
bright annealed
F Sheath (simplified view)
I Electrode thread
K Electrode rod insulation, PTFE

20 NRG 26-60 - Installation & Operating Manual - 819875-01
Dimensions of the NRG 26-60
1 2
Max.
installed length
at 238 °C
Measuring
range
373 300
477 400
583 500
688 600
794 700
899 800
1004 900
1110 1000
1214 1100
1319 1200
1423 1300
1528 1400
1636 1500
2156 2000
OK
!
+
-
140
G ¾
Fig. 6
Size 41
All lengths and diameters
in mm
0
Nm
50 70 90
110
120 100 80 60
41
175
w = 70
26 237
1 338
20
Thermal insulation
provided at the site
Ø15