GESTRA NRGT 26-2 User manual

Original Installation & Operating
Manual
Level Transmitter
NRGT 26-2
850688-00
EN (USA)
English

2NRGT 26-2 - USA - Installation & Operating Manual - 850688-00
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................................................................................................. 8
Permitted system components......................................................................................................... 9
Improper use ........................................................................................................................................ 9
Basic safety information .................................................................................................................... 10
Required personnel qualifications..................................................................................................... 11
Notes on product liability................................................................................................................... 11
Function .............................................................................................................................................. 12
Technical data .................................................................................................................................... 14
Name plate/identification of the NRGT 26-2 ..................................................................................... 17
Factory settings.................................................................................................................................. 18
Overall view of the NRGT 26-2 ........................................................................................................... 19
Dimensions of the NRGT 26-2 ............................................................................................................ 20
Preparing for installation ................................................................................................................... 21
Installation.......................................................................................................................................... 22
Installing the NRGT 26-2................................................................................................................ 23
Example of installation with dimensional specification for NRGT 26-2........................................... 24
Aligning the terminal box................................................................................................................... 25
Functional elements of the NRGT 26-2.............................................................................................. 26
Electrical connection.......................................................................................................................... 27
Notes on electrical connection ....................................................................................................... 27
Connecting the 24V DC power supply ........................................................................................... 27
Connecting the actual value output (4-20mA)................................................................................ 27
Pin assignment of the M12 connector for non pre-wired control cables ......................................... 27

3NRGT 26-2 - USA - Installation & Operating Manual - 850688-00
Contents
Bringing into service .......................................................................................................................... 28
Change the default settings if necessary........................................................................................ 28
Calibration to the lower limit of the active measuring range “CAL.L” (0% calibration value) ............ 30
Independent rapid calibration at a water level of > 25% of the active measuring range
“CAL.P” ......................................................................................................................................... 31
Calibration to the upper limit of the active measuring range “CAL.H”
(100% calibration value) ................................................................................................................ 31
Setting the filter constant “Filt”...................................................................................................... 31
Manually initiating a display test .................................................................................................... 32
Checking the level display by raising or reducing the level ............................................................. 32
Checking function by initiating a test ............................................................................................. 32
Starting, operation and testing .......................................................................................................... 33
System malfunctions.......................................................................................................................... 36
Causes .......................................................................................................................................... 36
Indication of system malfunctions using error codes...................................................................... 37
Common application and usage errors........................................................................................... 39
Checking installation and function ................................................................................................. 41
Taking out of service.......................................................................................................................... 42
Cleaning the electrode of the level transmitter................................................................................. 43
Cleaning interval............................................................................................................................ 43
Disposal .............................................................................................................................................. 43
Returning decontaminated equipment.............................................................................................. 43
UL Listed components........................................................................................................................ 43

4NRGT 26-2 - USA - Installation & Operating Manual - 850688-00
Content of this Manual
Product:
■ Level transmitter NRGT 26-2
First edition:
BAN 850688-00/05-2021cm
© Copyright
All rights reserved. Any misuse, particularly reproduction and dissemination to third parties, is not
permitted. The General Terms & Conditions of GESTRA AG apply.
Scope of delivery/Product package
■ 1 Level transmitter NRGT 26-2
■ 1 Installation & Operating Manual
Required accessories for NRGT 26-2 when installing for the first time
■ 1 Cable jack Binder series 713 99-0436-58-05

5NRGT 26-2 - USA - Installation & Operating Manual - 850688-00
How to use this Manual
This Installation & Operating Manual describes the correct use of the NRGT 26-2 level transmitter.
It applies to persons who integrate this equipment in 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.
■ 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 acces-
sible 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

6NRGT 26-2 - USA - Installation & Operating Manual - 850688-00
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.

7NRGT 26-2 - USA - Installation & Operating Manual - 850688-00
Specialist terms / Abbreviations
Here, we explain some abbreviations, specialist terms, etc., which are used in this Manual.
NRGT .. / NRR.. / NRS.. / URS .. / URB .. / SRL .. / etc.
Equipment and type designations of GESTRA AG.
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 output, pressure,
and temperature.
The design data may be a lot more stringent, however.
A boiler that is operated at 145psi (10bar) and 356°F (180°C) may be designed to withstand a
pressure of 870psi (60bar) and a temperature of 527°F (275°C), for example, which is therefore
not necessarily its operating point.

8NRGT 26-2 - USA - Installation & Operating Manual - 850688-00
Usage for the intended purpose
Use as a water level controller
The NRGT 26-2 level transmitter can be used to continually measure the water level in steam
boiler and hot-water plants, or in condensate and feedwater tanks. The calibrated measuring range
from 0% to 100% constitutes the linear profile of the 4-20mA current output. The NRGT 26-2 is
classified as operating control in accordance with UL60730-1.
Influence of the fluid to be monitored
■ The NRGT 26-2 level transmitter can be used in fluids with different conductivity. However, a
conductivity 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 (see page 30) at the
operating point* and after a cold start.
* Operating point of the plant, see page 7.
■ To achieve the best possible reproducibility and maintain high-quality measurements (see
“Technical data” on page 14), the sensor must be installed in a level pot – when installed
inside a protective tube (see „"Example of installation with dimensional specification for NRGT
26-2“ on page 24 ff.).
■ The dielectric constant of the fluid to be monitored may require an adjustment to the measure-
ment frequency if it deviates significantly from that of the usual water (εr = 80). Please contact
GESTRA AG Service about this.
Applicable directives and standards
The NRGT 26-2 level transmitter has been tested and approved for use in the scope governed by
the following directives and standards:
Standards:
■ UL 60730-1 and CAN/CSA E60730-1 General Requirements for Automatic Electrical Controls
■ UL 60730-2-15 and CAN/CSA E60730-2-15 Requirements for Automatic Electrical
Water Level Sensing Controls

9NRGT 26-2 - USA - Installation & Operating Manual - 850688-00
Usage for the intended purpose
Permitted system components
According to UL60730-2-15, the NRGT 26-2 level electrode can be regarded as an operating con-
trol, which delivers the measured water level via the 4-20mA output. Any electronic control unit
with an input for a 4-20mA unit signal can be connected and used for analysis.
To ensure proper use in all applications, please also read the Installation & Operating
Manuals for the system components used.
■ You can find the latest Installation & Operating Manuals for other system components
on our website:
http://www.gestra.com
Improper use
There is a danger of death due to explosion if the equipment is used in potentially
explosive 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 NRGT 26-2 - USA - Installation & Operating Manual - 850688-00
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 0psi (0bar) boiler pressure.
Risk of severe burns if work is performed on level electrode that is still hot. The
level electrode becomes very hot during operation.
■ Allow the level electrode to cool.
■ Always wait for the level electrode to cool before performing any installation and
maintenance work.
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 NRGT 26-2 level electrode due to the sudden escape of
hot steam or hot water.
Shocks and impacts during transport or installation can result in damage to or leaks in
the level electrode, causing pressurized hot steam or hot water to escape through the
pressure relief hole.
■ To prevent damage during transport and installation, do not expose the electrode
rod to major shocks 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 NRGT 26-2 level electrode may only be repaired by the manufacturer, GESTRA AG.
■ Only replace faulty equipment with identical equipment from GESTRA AG.
Basic safety information

11NRGT 26-2 - USA - Installation & Operating Manual - 850688-00
Required personnel qualifications
Activity Personnel
Integration in control system Specialist staff Plant designer
Installation/
electrical connection/
bringing into service
Specialist staff
The equipment may only be installed,
wired and commissioned by qualified and
competent staff.
Operation Boiler service technician Staff trained by the plant operator.
Maintenance work Specialist staff
Maintenance and refits may only be
performed by authorized staff who have
undergone specific training.
Refits Specialist staff Persons trained by the plant operator to work
with pressure and temperature.
Fig. 1
Notes on product liability
The manufacturer cannot accept any liability for damages resulting from improper use of the
equipment.

12 NRGT 26-2 - USA - Installation & Operating Manual - 850688-00
Function
The NRGT 26-2 level transmitter uses the capacitance measurement principle and converts level data
into a level-dependent 4-20mA current signal. The 0-100% measuring range can be scaled based
on the effective length of the electrode rod.
Automatic self-test
An automatic self-test periodically monitors the safety and function of the level transmitter and
measured value acquisition.
Faults in the electrical connection or electronic measuring equipment trigger an error indication on
the display, and the current output is set to 0mA.
Transmitter function
The transmitter function is the ability of the electrode to provide a scalable measuring range on the
4-20mA current output interface and to make this available to one or more recipients for analysis.
These devices do not have any controlling or limiting functions.
Level transmitters can be installed on the inside of steam boilers, tanks or feed lines of hot-water
plants. A protective tube installed on the system ensures reliable function. They can also be
installed in an external level pot that communicates with the boiler.
A capacitive NRGT 26-2 level transmitter can be installed in the same protective tube or level pot
as a conductive NRG 1x-50 or NRG 1x-51 level electrode.
Display and signals; see page 33 / 36
The NRGT 26-2 level transmitter has a green 4-digit, 7-segment display for showing readings,
status information and error codes. A red and a green LED indicate the operating status.

13NRGT 26-2 - USA - Installation & Operating Manual - 850688-00
Function
Behavior when powered on
The display alternately shows the software version, the type and then the scaled level reading.
Behavior in normal operation (no errors)
The display shows the scaled level reading (3 digits + 1 decimal place), e.g., 050.3, and converts the
level data into a level-dependent current signal from 4-20mA.
The scale of the 0-100% measuring range is factory-set to maximum for the electrode
length used. This way, meaningful level readings can be obtained immediately after
installation.
Adjusting the measuring range when bringing into service (CAL.L, CAL.P or CAL.H)
When bringing into service, however, the measuring range should be adapted in line with the sight
glass. Do this using the parameters CAL.L, CAL.P or CAL.H, see page 30 - 31. This is the only
way to gain all the benefits of high-resolution readings in the sight glass range.
Behavior in the event of malfunctions
The error state or malfunction is indicated by an error code shown continuously on the display, e.g.,
E.005. For more on error codes, see page 37.
Every time there is a malfunction, 0mA is output via the current output.
Electrode malfunctions are acknowledged automatically
When the malfunction is corrected, the indication disappears from the display, and the
NRGT 26-2 level transmitter returns to normal operation.
The tables on pages 34 - 35 clearly show the relationship between the equipment
status, the display, and the status LEDs.
Setting parameters and changing default settings
If necessary, you can adapt the electrode parameters to suit conditions at the plant. You can set
parameters and change default settings using a rotary knob on the terminal box, see page 29.

14 NRGT 26-2 - USA - Installation & Operating Manual - 850688-00
Technical data
Design and mechanical connection
■ NGRT 26-2 Thread ¾"-14 NPT, see Fig. 5
Nominal pressure rating, permitted service pressure and temperature
■ NRGT 26-2 464psi at 460°F (32bar at 238°C)
Materials
■ Terminal box 3.2581 G AlSi12, powder-coated
■ Cover tube 1.4301 X5 CrNi 18-10
■ Electrode rod insulation PTFE
■ Screw-in body 1.4404 / F316L
Max. electrode length at 460°F (238°C)
■ NRGT 26-2
Max. electrode
length:
14.70 inch
(373 mm)
18.80 inch
(477 mm)
22.95 inch
(583 mm)
27.10 inch
(688 mm)
31.25 inch
(794 mm)
35.40 inch
(899 mm)
39.55 inch
(1004 mm)
Measuring
range:
11.80 inch
(300 mm)
15.75 inch
(400 mm)
19.70 inch
(500 mm)
23.65 inch
(600 mm)
27.60 inch
(700 mm)
31.50 inch
(800 mm)
35.50 inch
(900 mm)
Max. electrode
length:
43.70 inch
(1110 mm)
47.80 inch
(1214 mm)
51.95 inch
(1319 mm)
56.05 inch
(1423 mm)
60.20 inch
(1528 mm)
64.45 inch
(1636 mm)
84.90 inch
(2156 mm)
Measuring
range:
39.37 inch
(1000 mm)
43.30 inch
(1100 mm)
47.25 inch
(1200 mm)
51.20 inch
(1300 mm)
55.10 inch
(1400 mm)
59.05 inch
(1500 mm)
78.75 inch
(2000 mm)
Do not shorten the electrode rod.

15NRGT 26-2 - USA - Installation & Operating Manual - 850688-00
Technical data
Measurement quality
The information below applies to a compensated fluid conductivity range from 100-10000µS/cm
based on 77°F (25°C).
■ Reading error: +/-1% from the set measuring range at the operating point
■ Resolution of reading on display: 0.1%
■ Resolution for internal processing: 15 bits with sign (16 bits)
■ Resolution of 4-20mA output: 15 bits equivalent to 0.49μA/digit
Supply voltage
■ 24V DC +/-20% SELV / PELV / CLASS2
Power consumption
■ Max. 7W
Current input
■ Max. 0.3A
Internal fuse
■ T2A (slow blow)
Safety cutout at excessive ambient temperature
■ Shutdown at excessive ambient temperature takes place at Tamb. = 167°F (75°C)
Analog output
■ 1 actual value output 4-20mA, proportional to level, galvanically isolated
■ Maximum output load 500Ω
■ M12 connector, 5-pole, A-coded
Indicators and controls
■ 1 green 4-digit, 7-segment display for showing status information
■ 1 red LED for indicating the error state
■ 1 green LED for indicating the OK state
■ 1 rotary knob IP65 with button for menu navigation and test function
Protection class
■ III Safety Extra Low Voltage SELV / PELV / CLASS2
IP rating
■ NEMA type 3R, 3RX and 5
■ IP 65 to EN 60529
Other information
■ Independently mounted Type 1 action operating control
■ Pollution degree 2, impulse voltage 330V

16 NRGT 26-2 - USA - Installation & Operating Manual - 850688-00
Technical data
Permitted ambient conditions
■ Service temperature: 32-158°F (0-70°C)
■ Storage temperature: -40-176°F (-40-80°C)
■ Transport temperature: -40-176°F (-40-80°C)
■ Air humidity: 10% - 95%, non-condensing
Weight (dependent on length of electrode)
■ NRGT 26-2 approx. 3.96lb (1.8kg) with 11.81inch (300mm) measuring range
Permitted installation positions
■ Vertical
■ Maximum inclination of 45°. In this case, the length of the electrode rod is limited
to maximum 27.1inch (688mm)
■ A protective tube [NPS 2 (DN 50)] is required for internal installation

17NRGT 26-2 - USA - Installation & Operating Manual - 850688-00
OPERATING CONTROL
E513189
Output rating: 4-20mA
Input voltage: 24VDC
Input power: 7W
Environmental rating: NEMA Type 3R / 3RX / 5
Name plate/identification of the NRGT 26-2
The date of production is stamped on the screw-in body of the level transmitter.
Power consumption
Safety
note
Equipment designation
Nominal pressure rating,
connection thread,
material of
screw-in body
Equipment function
Permitted service pressure,
permitted temperature
Current
approval
Manufacturer
Serial number
IP rating
Supply voltage
CE marking
Appointed authority
Protection class
Disposal information
Fig. 2
Measuring range
Actual value output
Permitted ambient
temperature
Betriebsanleitung
beachten
See installation instructions
Voir instructions de
montage
GESTRA AG
Münchener Str. 77
28215 Bremen
Made in Germany
NRGT 26-2
158°F (70°C)T
PmaxPmax
TmaxTmax
3/4-14NPT 1.4404/F316L IP65
464psi (32bar)
460°F (238°C)
H= mm
Niveautransmitter
Level Transmitter
Transmetteur de niveau
7W
OUT: 4-20mA / 500
V 20%24 ±
Tamb

18 NRGT 26-2 - USA - Installation & Operating Manual - 850688-00
Factory settings
The NRGT 26-2 level transmitter is delivered ex works with the following settings.
Menu display Parameter values Unit
CAL.L Variable 0% Raw value (hex)
approx. 50mV
CAL.P Variable 25% Raw value (hex)
CAL.H Variable 100% Raw value (hex)
approx. 2.0V
FiLt 0005 Seconds
Fig. 3

19NRGT 26-2 - USA - Installation & Operating Manual - 850688-00
Overall view of the NRGT 26-2
Fig. 4
A Terminal box
B Operating panel with 4-digit LED display/
error and status LEDs and rotary knob, see
page 33
C M12 connector, 5-pole, A-coded
F Electrode
D Cover tube (simplified view)
E Electrode thread
G Electrode rod insulation, PTFE
OK
!
+
-

20 NRGT 26-2 - USA - Installation & Operating Manual - 850688-00
Dimensions of the NRGT 26-2
Fig. 5 All lengths and diameters in inches
(mm)
1 2
Max.
electrode length
at 460°F (238°C)
Measuring range
14.70 inch (373 mm) 11.80 inch (300 mm)
18.80 inch (477 mm) 15.75 inch (400 mm)
22.95 inch (583 mm) 19.70 inch (500 mm)
27.10 inch (688 mm) 23.65 inch (600 mm)
31.25 inch (794 mm) 27.60 inch (700 mm)
35.40 inch (899 mm) 31.50 inch (800 mm)
39.55 inch (1004 mm) 35.50 inch (900 mm)
43.70 inch (1110 mm) 39.37 inch (1000 mm)
47.80 inch (1214 mm) 43.30 inch (1100 mm)
51.95 inch (1319 mm) 47.25 inch (1200 mm)
56.05 inch (1423 mm) 51.20 inch (1300 mm)
60.20 inch (1528 mm) 55.10 inch (1400 mm)
64.45 inch (1636 mm) 59.05 inch (1500 mm)
84.90 inch (2156 mm) 78.75 inch (2000 mm)
OK
!
+
-
5.5 inch (140 mm)
6.9 inch (175 mm)
13.35 inch (338 mm)
1
W = 1.76 inch (70 mm)
¾" - 14 NPT
2
Thermal insulation
provided on site
0.8 inch (20 mm)
1.5 inch
(37 mm)
Ø0.6 inch (15 mm)
1.05 inch
(26 mm)
Size 41