GESTRA NRG 16-36 Original Installation Instructions - User Manual

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E N

E n g l i s h

Level Electrode

NRG 16-36

Original Installation Instructions

819257-01

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

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

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.

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.

TÜV . WR / WB . xx-424

0525

TÜV . SWB . xx-422

Mat-Nr.:

32 bar (464psi)
238°C (460°F)
T amb = 70°C (158 °F)

NRG 16-36

GESTRA AG

Münchener Straße 77

D-28215 Bremen

Pmax

Tmax

PN 40 G1 1.4571 IP 65

Betriebsanleitung beachten
See installation instructions

Voir instructions 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

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

- continued -

Dimensions NRG 16-36

Fig. 2

NRG 16-36 (dimensions are applicable for conductivity

> 10 μS/cm / measuring length < 1000 mm)

228

∅

400,

1000,

1500

≥

Fig. 3

NRG 16-36 (dimensions are applicable for conductivity

< 10 μS/cm / measuring length > 1000 mm)

Installation

Thermal insulation, provided on site, d = 20

mm (outside of thermal insulation of steam

boiler)

Terminal box

Screwed BSP 1 ½ A, ISO 228

Joint ring 48 x 55 form D to DIN 7603, made

from 2.4068, bright annealed

Electrode tips 6, 7 and 8

Electrode tip for low water (LW)

Key

Insulation of electrode tips

Spacer disc

Measuring surface extension for electrode

tips 6, 7 and 8

Measuring surface extension for low water

(LW)

Set screw

Retaining ring

Fig. 4

N10

G1½, ISO 228-1

∅

0.5

Dimensions NRG 16-36

17 / 50

X-2

Fig. 5

- continued -

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

not 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

6 7 8

and the central electrode tip for

low water

3. Only for

Fig. 3:

Reduce the length of the electrode tips

6 7 8

by 2 mm to compensate for the

measuring surface extension

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

7. Slip spacer disc

onto electrode tips at equal distances.

Fig. 4

9. Attach a measuring surface extension

(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

onto the central electrode tip (LW) and fasten it with the

set screw

11. Put the retaining ring

onto the central electrode tip.

Installation

NRG 16-36, step 2

12. Check seating surfaces.

Fig. 5

13. Place supplied joint ring

onto 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

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

1+2+3+4

Pump ON

Pump OFF

MAX alarm

Table "Functions"

- continued -

Examples of installation

NRG 16-36

Flange PN 40, DN 50, DIN EN 1092-01

For the approval of the boiler standpipe with

connecting flange the relevant regulations

must be considered.

Vent hole

Provide vent hole as close to the boiler wall as possible!

Distance between electrode tips and protection

tube ≥ 14 mm

Protection tube DN 100

Low water LW

Key

≤

90°

∅

G 1½

≥10

DN 50

∅

1000,

1500

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

Centre distance

≤

G 1½

DN 20

≤

Reducer DIN 2616-2,

K-114,3 x 3,6 – 48,3 x 2,9 W

Flange PN 40, DN 100, DIN EN 1092-01

High water (HW)

Level pot ≥ DN 100

Electrode tips

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 mm

, e. g. LiYCY 4 x 0.5 mm

, 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 mm

Li2YCY PiMF 2 x 2 x 0.5 mm

, 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 mm

, e. g. LiYCY 5 x 0.5 mm

, max. length 100 m.

Connect the screens

only once

to the central earthing point

(CEP)

in the control cabinet.

NRG 16-36

Electrical connection

Wiring diagram

Fig. 8

Level electrode NRG 16-36

NRS 1-50 with response sensitivity 0.5 µS/cm:

Connect the two internal screens to terminal 5 and the

CEP

Central earthing point (CEP) in control cabinet

Terminal box

Cable gland for low water LW

Cable gland for water level controller (electrode tips 6, 7 and 8)

Key

MAX

Pump OFF

Pump ON

Low water LW

Level switch NRS 1-50

Level switch NRS 1-54

Fig. 9

NWB

Contr.

NTB

Rég.

Reg.

- continued -

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.