GESTRA NRG 16-36 User manual

EN
English
Level Electrode
NRG 16-36
Original Installation Instructions
819257-01

2
Contents
Page
Contents
Important notes
Usage for the intended purpose...............................................................................................................4
Function..................................................................................................................................................4
Safety note..............................................................................................................................................4
Directives and standards
Pressure Equipment Directive (PED) 2014/68/EU.....................................................................................5
Functional Safety acc. to IEC 61508 ........................................................................................................5
VdTÜV Bulletin "Wasserstand 100" (= Water Level 100)..........................................................................5
ATEX (Atmosphère Explosible) .................................................................................................................5
Note on the Declaration of Conformity / Declaration by the Manufacturer ..........................................5
Technical data
NRG 16-36..............................................................................................................................................6
Scope of supply ......................................................................................................................................6
Name plate/marking ...............................................................................................................................6
Installation
Tools.......................................................................................................................................................7
Dimensions NRG 16-36...........................................................................................................................8
Key .........................................................................................................................................................9
NRG 16-36, step 1 ................................................................................................................................10
NRG 16-36, step 2 ................................................................................................................................10
Table "Functions"..................................................................................................................................10
Examples of installation
NRG 16-36............................................................................................................................................11

3
Contents
Page
- continued -
Key .......................................................................................................................................................11
Electrical connection
Connection of level electrode ................................................................................................................12
NRG 16-36, connecting terminals..........................................................................................................12
Tools.....................................................................................................................................................12
Wiring diagram .....................................................................................................................................13
Key .......................................................................................................................................................13
Commissioning, fault indication and troubleshooting ......................................................................14
Removing and disposing of the level electrode
Removing and disposing of level electrode NRG 16-36..........................................................................14

4
Important notes
Usage for the intended purpose
The level electrode NRG 16-36 is used in conjunction with level switch NRS 1-50 as water level limiter
for steam boilers and (pressurized) hot-water installations and in conjunction with level switches NRS
1-52 / NRS 1-54 or NRS 1-2 / NRS 1-5 as water level controller.
Water level limiters switch off the heating when the water level falls below the set minimum level (low
water).
Function
The NRG 16-36 is a combination level electrode consisting of 1 level-limiting electrode tip for low level
alarm (LW) and 3 electrode tips for water level control with high level alarm (MAX).
The electrode operation is based on the conductive measuring principle using the electrical conductiv-
ity of the water for signalling water level. The high integrity self-monitoring function in the level limiter
ensures that an alarm will also be triggered if the electrode insulation is contaminated or has devel-
oped a leak and/or if there is a malfunction in the electrical connection.
The length of the individual electrode rods determines the switchpoints for the respective water levels.
The level electrode is installed inside steam boilers, vessels or in an external level pot. If the electrode
is installed inside the boiler or vessel, a protection tube provided on side ensures correct functioning.
(see section Examples of installation page 11).
If the level electrode is installed in an isolatable level pot outside the boiler, make sure that the con-
necting lines are rinsed regularly. In addition, the logic unit SRL is required to monitor the purging
times and the purging sequence. If the connecting lines for steam ≥ 40 mm and water ≥ 100mm, the
installation is considered to be internal. In this case the rinsing processes do not have to be monitored.
Safety note
Danger
When loosening the electrode steam or hot water might escape!
This presents the risk of severe scalding all over the body!
It is therefore essential not to dismantle the electrode unless the boiler pressure is
verified to be 0 bar.
The electrode becomes hot during operation.
Risk of severe burns to hands and arms.
Before carrying out installation and maintenance work make sure that the steam trap is
cold.
Attention
The name plate specifies the technical features of the equipment. Do not commission or
operate any item of equipment that does not bear its specific name plate.
This device is an item of equipment with safety function (PED) and must only be installed, wired and
commissioned by qualified and competent staff.
Retrofitting and maintenance work must only be performed by qualified staff who - through adequate
training - have achieved a recognised level of competence.

5
Directives and standards
Pressure Equipment Directive (PED) 2014/68/EU
Water level limiters are safety accessories as defined in the Pressure Equipment Directive (PED). The
level electrode NRG 16-36 in conjunction with level switch NRS 1-50 is EC type approved according to
EN 12952/EN 12953. These Directives state, among other things, the requirements made on limiting
systems and equipment for steam boiler plants and (pressurised) hot-water installations.
ATEX (Atmosphère Explosible)
The level electrodes NRG 1...-50, NRG 1...-11 and NRG 16-36 are simple items of electrical equipment
as specified in EN 60079-11 section 5.7. According to the European Directive 2014/34/EU the equipment
must be equipped with approved Zener barriers if used in potentially explosive areas. Applicable in
Ex zones 1, 2 (1999/92/EC). The equipment does not bear an Ex marking.
Note that the requirements of the IEC 61508 are not met if the NRG 1...-50, NRG 1...-11, NRG 16-36 +
Zener barriers + NRS 1-50 are interconnected!
VdTÜV Bulletin "Wasserstand 100" (= Water Level 100)
The level electrodes NRG 1-50, NRG 1...-11 and NRG 16-36 in conjunction with the level switch
NRS 1-50 are type approved according to the VdTÜV Bulletin "Water Level 100".
The level electrode NRG 16-36 is also type approved in conjunction with level switches NRS 1-52 /
NRS 1-55 or NRS 1-2 / NRS 1-5.
The VdTÜV Bulletin "Wasserstand (=Water Level) 100" specifies the requirements made on water level
control and limiting equipment for boilers.
Functional Safety acc. to IEC 61508
The level electrodes NRG 1...-50 / NRG 16-36 are certified acc. to IEC 61508 only if used in
combination with level switch NRS 1-50. This standard describes the functional safety of safety-
related electrical/electronic/programmable electronic systems.
The equipment combination NRG 1...-50 or NRG 16-36 + NRS 1-50 corresponds to a type B sub-
system with Safety Integrity Level (SIL) 3.
Note on the Declaration of Conformity / Declaration by the Manufacturer
For details on the conformity of our equipment according to the European Directives see our
Declaration of Conformity or our Declaration of Manufacturer.
The current Declaration of Conformity / Declaration of Manufacturer are available in the Internet under
www.gestra.com/documents or can be requested from us.

6
TÜV . WR / WB . xx-424
0525
TÜV . SWB . xx-422
Mat-Nr.:
32bar (464psi)
238°C (460°F)
Tamb = 70°C (158 °F)
NRG 16-36
GESTRA AG Münchener Straße 77 D-28215 Bremen
Pmax
Tmax
PN40 G1 1.4571 IP 65
/
12
Betriebsanleitung beachten
See installation instructions
Voirinstructions de montage
NRG 16-36
Technical data
Operating pressure
PN 40, 32 bar at 238 °C
Mechanical connection
Screwed BSP 1 ½ A, ISO 228
Materials
Screw-in body 1.4571, X6CrNiMoTi17-12-2
Electrode tips 1.4571, X6CrNiMoTi17-12-2
Electrode insulation Gylon®, PTFE
Spacer disks PTFE
Terminal box 3.2161 G AlSi8Cu3
Lengths available
400mm, 1000 mm, 1500 mm
Electrical connection
Terminal box made from aluminium, 2 cable glands Pg 11
Protection
IP 65 to EN 60529
Max. admissible ambient temperature
Max. 70 °C
Weight
Approx. 4.5 kg (L=1000 mm)
Approvals:
TÜV certificate VdTÜV Bulletin "Water Level 100"
Requirements made on water level limiting & control equipment.
Type approval no. TÜV · WR / WB · XX-370; XX-424; SWB · XX-422
(see name plate)
Gylon® is a registered trademark of Garlock Sealing Technologies, Palmyra NY, USA
Scope of supply
NRG 16-36
1 Level electrode NRG 16-36, PN 40
1 Joint ring 48 x 55, form D to DIN 7603, made from 2.4068, bright annealed
1 Installation manual
Name plate/marking
Equipment designation Safety note
Disposal note
CE Marking
Type approval no.
Manufacturer Pressure rating, thread type, material
number, protection
Application range
Fig. 1

7
Note
For the approval of the boiler standpipe the relevant regulations must be considered.
Refer to pages 11 for typical installation examples.
If installed outdoors the level electrode must be equipped with a GESTRA weather
protection cover.
The level electrode shall be installed vertically.
The seating surfaces of the standpipe or the flange provided on the vessel must be
accurately machined, see Fig. 3.
Do not bend electrode tips when mounting.
Do not subject electrode tips to physical shocks.
Use only the supplied joint ring 48 x 55, form D, DIN 7603, made from 2.4068,
bright annealed!
Do not lag electrode body above the hexagonal section.
Do not insulate electrode thread with hemp or PTFE tape!
Do not apply conductive paste or grease to the electrode thread!
Make sure that the air distance between the electrode tips and earth
(flange, vessel wall) is not less than 14 mm. Fig. 6 - 7.
Observe the minimum withdrawal distance when installing the electrode!
The specified torques must be strictly observed.
Attention
Tools
Open-end spanner A. F. 55, DIN 3110, ISO 3318
Scriber
Bolt cutter
Flat file, medium cut, DIN 7261, form A
Installation

8
Installation - continued -
Dimensions NRG 16-36
Fig. 2
NRG 16-36 (dimensions are applicable for conductivity
> 10 μS/cm / measuring length < 1000 mm)
228
∅23
53
1
2
4
75
400, 1000, 1500
3
5050
0
5
≥14
8
≥ 14
55
≥ 5
≥ 5≥ 14
8
≥ 14
Fig. 3
NRG 16-36 (dimensions are applicable for conductivity
< 10 μS/cm / measuring length > 1000 mm)
9
9
9
5
0
6
6

9
Installation
1Thermal insulation, provided on site, d = 20
mm (outside of thermal insulation of steam
boiler)
2Terminal box
3Screwed BSP 1 ½ A, ISO 228
4Joint ring 48 x 55 form D to DIN 7603, made
from 2.4068, bright annealed
5Electrode tips 6, 7 and 8
6Electrode tip for low water (LW)
Key
7Insulation of electrode tips
8Spacer disc
9Measuring surface extension for electrode
tips 6, 7 and 8
0Measuring surface extension for low water
(LW)
aSet screw
bRetaining ring
Fig. 4
N8
N10
G1½, ISO 228-1
∅56
0.5
Dimensions NRG 16-36
17 / 50
X-2
2
2
7
8
9
a
b
0
Fig. 5
5
- continued -
- continued -

10
1. Determine required measuring lengths of electrode tips and enter data in table "Functions".
Fig. 2: Dimensions are applicable for installation in water with a conductivity > 10 µS/cm
/ measuring length < 1000 mm. Measuring surface extension 9not required
Fig. 3: Dimensions are applicable for installation in water with a conductivity < 10 µS/cm
/ measuring length > 1000 mm.
2. Use a bolt cutter to cut the three radial electrode tips 678 and the central electrode tip for
low water LW.
3. Only for Fig. 3: Reduce the length of the electrode tips 678 by 2 mm to compensate for the
measuring surface extension 9.
4. Deburr faces of electrode tips.
5. Strip off 50 mm Fig. 2 or 17 mm Fig. 3 of the PTFE insulation from the ends of the electrode tips.
Fig. 4
6. A plastic bag with screws, spacer discs and measuring surface extensions is included in the
terminal box 2.
7. Slip spacer disc 8onto electrode tips at equal distances. Fig. 4
9. Attach a measuring surface extension 9(only required in Fig. 3) to each of the electrode tips
arranged radially around the central electrode tip. Fig. 4
10. Attach measuring surface extension 0onto the central electrode tip (LW) and fasten it with the
set screw a.
11. Put the retaining ring bonto the central electrode tip.
Installation
NRG 16-36, step 2
12. Check seating surfaces. Fig. 5
13. Place supplied joint ring 4onto seating surface of the threaded standpipe or flange. Fig. 5
14. Apply a light smear of heat resistant silicone grease (e.g. WINIX®2150) to electrode thread 3.
15. Screw level electrode into threaded standpipe or flange and tighten with an open-end spanner A. F.
55 mm. The torque required when cold is 490 Nm.
NRG 16-36, step 1
Function of electrode tip Connecting terminal Length [mm]
Please enter length
Low water LW 1+2+3+4
Pump ON 6
Pump OFF 7
MAX alarm 8
Table "Functions"
- continued -

11
Examples of installation
NRG 16-36
cFlange PN 40, DN 50, DIN EN 1092-01
dFor the approval of the boiler standpipe with
connecting flange the relevant regulations
must be considered.
eVent hole Provide vent hole as close to the boiler wall as possible!
fDistance between electrode tips and protection
tube ≥ 14 mm
gProtection tube DN 100
hLow water LW
Key
c
d
≤ 90°
∅ 20
e
G 1½
≥10
DN 50
∅20
g
f
f
1000, 1500
i
h
Fig. 6 Protection tube (provided on site) if electrode
is used as internal water-level limiter
Fig. 7 Level pot if electrode is used as external water
level limiter
DN 20
DN 20
Centre distance
≤ 20
G 1½
DN 20
≤20
j
m
k
h
l
iReducer DIN 2616-2,
K-114,3 x 3,6 – 48,3 x 2,9 W
jFlange PN 40, DN 100, DIN EN 1092-01
kHigh water (HW)
lLevel pot ≥ DN 100
mElectrode tips
.
h

12
Electrical connection
Tools
Screwdriver, size 1
Screwdriver, size 2.5, completely insulated according to DIN VDE 0680-1
Please observe the instructions given in the installation & operating manual for the
NRS 1-50, NRS 1-52, NRS 1-54 or NRS 1-1, NRS 1-2 and NRS 1-5.
Make sure that connecting cables leading to the level electrode are segregated and
run separately from power cables.
Check the connection of the screen to the central earthing point (CEP) in the control
cabinet.
Attention
NRG 16-36, connecting terminals
1. Unscrew the fixing screws and remove the terminal box.
Loosen cable gland.
2. Pull the cables for connecting the electrode tip for low water LW and the three radial electrode tips
6, 7 and 8 through the associated cable glands. Fig. 9
3. Connect terminals according to the wiring diagram Fig. 8 and table "Functions" on page 10.
4. Tighten the cable gland.
5. Put back the cover of the terminal box and fasten the fixing screws.
Make sure that the cover is properly seated.
Connection of level electrode
To connect the level electrode use two multi-core overall screened control cables in separated con-
duits.
To connect the level tip for low water level (LW) alarm please use:
For the level switch NRS 1-50 with a response sensitivity of 10 μS:
Multi-core screened control cable, min. conductor size 0.5 mm2, e. g. LiYCY 4 x 0.5 mm2, max.
length 100 m.
For the level switch NRS 1-50 with a response sensitivity of 0.5 μS:
Multi-core double-screened low-capacitance data cable, min. conductor size 0.5 mm2,
Li2YCY PiMF 2 x 2 x 0.5 mm2, max. length 30 m.
Wire terminal strip in accordance with the wiring diagram. Fig. 8. Wire the screens to terminal 5 and
the central earthing point (CEP) in the control cabinet.
To connect the electrode tips 6, 7 and 8 use multi-core overall screened control cable, min. conductor size
0.5 mm2, e. g. LiYCY 5 x 0.5 mm2, max. length 100 m.
Connect the screens only once to the central earthing point (CEP) in the control cabinet.

13
12345678
NRG 16-36
82 5
3647
1
1234567
Electrical connection
Wiring diagram
Fig. 8
nLevel electrode NRG 16-36
oNRS 1-50 with response sensitivity 0.5 µS/cm:
Connect the two internal screens to terminal 5 and the CEP.
pCentral earthing point (CEP) in control cabinet
qTerminal box
rCable gland for low water LW
sCable gland for water level controller (electrode tips 6, 7 and 8)
Key
n
MAX
Pump OFF
Pump ON
Low water LW
Level switch NRS 1-50 Level switch NRS 1-54
p
o
p
Fig. 9
1
NWB WR
LW Contr.
NTB Rég.
NB Reg.
5263748
q
r s
- continued -

14
Commissioning, fault indication and troubleshooting
For additional information on commissioning procedures and troubleshooting refer to the installation &
operating manuals for level switch NRS 1-50, NRS 1-52, NRS 1-54 or NRS 1-1, NRS 1-2 and NRS 1-5!
If faults occur that are not listed above or cannot be corrected, please contact our service centre or
authorized agency in your country.
Removing and disposing of the level electrode
Removing and disposing of level electrode NRG 16-36
1. Unscrew the fixing screws and remove the terminal box. Loosen cable gland.
2. Detach all cables and pull the cable glands.
3. Before removing the equipment make sure that is is neither hot nor under pressure.
For the disposal of the equipment observe the pertinent legal regulations concerning waste disposal.
Danger
When loosening the electrode steam or hot water might escape!
This presents the risk of severe scalding all over the body!
It is therefore essential not to dismantle the electrode unless the boiler pressure is
verified to be 0 bar.
The electrode becomes hot during operation.
Risk of severe burns to hands and arms.
Before carrying out installation and maintenance work make sure that the equipment is
cold.

15
For your Notes

819257-01/04-2017csa (808906-01) · GESTRA AG · Bremen · Printed in Germany
GESTRA AG
Münchener Straße 77
28215 Bremen
Germany
Telefon [phone]
Telefax [phone]
E-mail [email protected]
Web www.gestra.de
Agencies all over the world: www.gestra.de