Full Text Searchable PDF User Manual
1
E N
E n g l i s h
Level Electrode
NRG 16-50 S
Original Installation Instructions
819013-01
2
Contents
Usage for the intended purpose ..............................................................................................................4
Function .................................................................................................................................................4
Safety note .............................................................................................................................................5
Scope of supply ......................................................................................................................................5
Important notes
Page
NRG 16-50 S ..........................................................................................................................................6
Name plate/marking ...............................................................................................................................6
Dimensions NRG 16-50 S ......................................................................................................................7
Technical data
NRG 16-50 S ..........................................................................................................................................8
NRG 16-50 S, step 1 ...............................................................................................................................9
NRG 16-50 S, step 2 ...............................................................................................................................9
Tools .......................................................................................................................................................9
Examples of installation ........................................................................................................................10
Key .......................................................................................................................................................11
Installation
Electrical connection
NRG 16-50 S with four-pole connector ..................................................................................................12
Connection of level electrode ................................................................................................................13
NRG 16-50 S with four-pole connector ..................................................................................................13
Tools .....................................................................................................................................................13
Wiring diagram .....................................................................................................................................14
Key .......................................................................................................................................................14
3
Commissioning, fault indication and remedy
Danger .................................................................................................................................................15
Removing and disposing of electrode ....................................................................................................15
Note .....................................................................................................................................................15
Removing and disposing of electrode
NRG 16-50 S ........................................................................................................................................15
Contents
– continued –
Page
4
Important Notes
Usage for the intended purpose
The level electrode NRG 16-50 S is used in conjunction with level switch NRS 1-50 (de-energizing
delay: 15 seconds) as water-level limiter for steam boilers and (pressurized) hot-water installations on
board of seagoing vessels, mobile offshore platforms or river boats.
Water level limiters switch off the heating when the water level falls below the set minimum level (low
water).
Function
When the water level falls below the low level, the level electrode is exposed and a low level alarm is
triggered in the level switch NRS 1-50. This switchpoint “Low water level (LW)” is determined by the
length of the electrode tip.
After the de-energizing delay has elapsed, the two output contacts of the level switch NRS 1-50 will
open the safety circuit for the heating. The equipment has a factory set default de-energizing delay of
15 seconds to compensate for the the movements of the ship.
The self-monitoring function ensures that an alarm will also be triggered if the electrode insulation is
contaminated or has developed a leak or if there is a malfunction in the electrical connection.
The level electrode is installed inside steam boilers, vessels or inlet lines of hot-water systems. The
protective tube mounted on site (see section
Examples of Installation
(pages 10, 11)) ensures correct
functioning.
If the level electrode is installed in an isolatable level pot outside the boiler, make sure that the
connecting lines are rinsed regularly. In addition, the logic unit SRL 6-50 is required to monitor the
purging times and the purging sequence.
If the connecting lines for steam ≥ 40 mm and water ≥ 100 mm, the installation is considered to be
internal. In this case the rinsing processes do not have to be monitored.
5
Important Notes
– continued –
Safety note
Danger
When loosening the level 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 level electrode unless the boiler pressure is
verified to be 0 bar.
The level 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.
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.
Water level limiters are safety devices 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.
Scope of supply
NRG 16-50 S
1 Level electrode NRG 16-50 S, PN 40, DN 50
1 Installation manual
6
NRG 16-50 S
Technical data
Service pressure
PN 40, 32 bar at 238 °C
Mechanical connection
Flange
PN 40, DN 50, DIN 2527, form B
Materials
Sheath 1.4301, X5 CrNi18-10
Flange 1.0460 / A 105
Screw-in body 1.4571, X6CrNiMoTi17-12-2
Measuring electrode 1.4571, X6CrNiMoTi17-12-2
Electrode tip 1.4401, X5CrNiMo17-12-2
Electrode insulation Gylon
®
Four-pole connector Polyamid (PA)
Lengths available
500 mm, 1000 mm, 1500 mm, 2000 mm
Electrical connection
Four-pole connector, cable gland M 16
Protection
IP 65 to EN 60529
Max. admissible ambient temperature
70°C
Weight
Approx. 4.5 kg (without electrode tip)
Approvals
see data sheet
Gylon
®
is a registered trademark of Garlock Sealing Technologies, Palmyra NY, USA
Name plate / marking
Equipment designation
Safety note
Disposal note
Pressure rating, flange type,
material number
Manufacturer
Pressure/temperature rating
Fig. 1
7
Technical data
– continued –
Dimensions NRG 16-50 S
Fig. 2
NRG 16-50 S for
marine applications
80
≤ 2000
295
∅
165
Flange PN 40, DN 50,
DIN 2527, form B
bolt circle
∅
125
(4x
∅
18 for M 16)
8
Fig. 3
1
2
3
4
Installation
NRG 16-50 S
8
9
9
Fig. 4
5
1
Measuring electrode
2
Bore
3
Spring
4
Electrode tip
5
NRG 16-50 S with four-pole connector
Key
6
Anti-rotation element
7
Thermal insulation (provided on site) d=20 mm
(outside of thermal insulation of steam boiler)
8
Sealing surface
9
Flange joint (provided on site)
0
Connecting pipe socket (provided on site)
0
7
6
9
Installation
– continued –
NRG 16-50 S, step 1
1. Screw electrode tip
4
into measuring electrode
1
.
Fig. 3
2. Carefully determine required measuring length of electrode.
3. Mark length of electrode tip
4
.
4. Unscrew electrode tip
4
from measuring electrode
1
and cut tip.
5. After visual inspection screw electrode tip
4
into measuring electrode
1
. Slide spring
3
along
electrode tip
4
so that its end completely enters the small hole
2
.
NRG 16-50 S, step 2
6. Check seating surfaces.
Fig. 4
7. Put flange joint
9
onto connecting pipe socket
0
.
Fig. 4
8. Put level electrode onto connecting pipe socket and fix it with four bolts M 16.
9. Tighten bolts in diagonally opposite pairs. The tightening torque depends on the flange joint used.
n
Make sure that the sealing surface of the connecting pipe socket is accurately
machined!
n
Do not bend electrode tip when mounting.
n
Do not lag electrode body above the hexgonal section.
n
Observe minimum spacing of 14 mm between measuring electrode / electrode tip and
protection tube / level pot!
Fig. 5, Fig. 6
n
Observe the minimum spacings when installing the electrode!
Attention
Note
n
For the approval of the boiler standpipe the relevant regulations must be considered.
n
Refer to pages 10 for typical installation examples.
Tools
n
Open-end spanner A. F. 13, DIN 3110, ISO 3318
n
Scriber
n
Hacksaw
n
Flat file, medium cut, DIN 7261, form A
10
Installation
– continued –
g
Examples of installation for NRG 16-50 S
Fig. 6
Level pot if electrode is used
as external water-level limiter
a
Fig. 5
Protection tube (provided on site)
if electrode is used as internal water-level limiter
≥
14
≤
2000
≤
20
c
d
e
∅
20
≤
90°
≥
10
≥
14
DN 50
b
Centre
distance
≥
DN 20
≥
DN 20
DN 20
c
g
i
f
h
≥
20
≥
20
11
Installation
– continued –
a
For the approval of the boiler standpipe with connecting flange the relevant regulations must
be considered.
b
Vent hole
Provide vent hole as close to the boiler wall as possible!
c
Electrode tip
∅
8 mm
d
Protection tube
≥
DN 80
e
Distance between electrode tip and protection tube
≥
14 mm
f
Reducer DIN 2616-2, K-88.9 x 3,.2- 42.4 x 2.6 W
g
Low water (LW)
h
Level pot ≥ DN 80
i
High water HW
Key
12
Fig. 7
q
p
n
m
j
k
l
o
Electrical Connection
NRG 16-50 S with four-pole connector
j
Screw M 4
k
Cover
l
Upper part of the terminal box
m
Connecting plate
n
Insulating plate
o
Contact plate of level electrode
p
Cable strain relief
q
Cable gland M 16 (PG 9)
Key
13
Connection of level electrode
To connect the level electrode(s) use screened multi-core control cable with a min. conductor size
0.5 mm
2
, e.g. LiYCY 4 x 0.5 mm
2
.
Max. length 100 m with an electrical conductivity of the boiler water > 10 μS/cm at 25 °C.
Wire terminal strip in accordance with the wiring diagram.
Fig. 8, 9
Connect screens to terminals 5 and 13 and to the central earthing point
(CEP)
in the control cabinet.
Electrical Connection
– continued –
1. Undo screw
j
.
Fig. 7
2. Remove upper part
l
of the terminal box from the level electrode but leave insulating plate
n
on
contact plate
o
.
3. Remove cover
k
.
4. Press connecting plate
m
out of upper part of the terminal box
l
.
The upper part of the terminal box can be turned in steps of 90°.
5. Detach cable gland
q
and cable clamp
p
from upper part of the terminal box
l
.
6. Run cable through cable gland
q
and upper part of the terminal box
l
and wire terminals of the
connecting plate
m
in accordance with wiring diagram.
Fig. 8
7. Press connecting plate
m
into the upper part of the terminal box and align cable.
8. Fix cable with cable clamp
p
and cable gland
q
.
9. Put cover
k
in place and insert screw
j
.
10. Put upper part of the terminal box onto the level electrode and fix it with screw
j
.
NRG 16-50 S with four-pole connector
Tools
n
Screwdriver size 1
n
Screwdriver size 2.5, completely insulated according to DIN VDE 0680-1
n
Open-end spanner A.F. 18 (19) mm
14
Electrical Connection
– continued –
Wiring diagram
Fig. 10
Electrical connection of level
electrode with four-pole connector
Fig. 9
Wiring diagram
for equipment with TWO electrodes
r
r
s
s
Fig. 8
Wiring diagram
for equipment with ONE electrode
r
s
CEP
CEP
CEP
15
Key
r
Stand-by input 1 / 2, 24 V DC, for connecting the logic unit SRL
s
Level electrode NRG 1...-50S
CEP
Central earthing point in control cabinet
Commissioning, fault indication and remedy
For additional information on commissiong procedures and troubleshooting refer to the installation
manual of the level switch NRS 1-50.
Danger
Removing and disposing of electrode
Removing and disposing of electrode
1. Undo screw
j
.
Fig. 7
2 . Detach upper part of the terminal box
l
from the level electrode. 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.
If faults occur that are not listed above or cannot be corrected, please contact our service centre or
authorized agency in your country.
When loosening the level 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 level electrode unless the boiler pressure is
verified to be 0 bar.
The level 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.
Electrical Connection
– continued –
Note
When ordering spare parts or replacement equipment please state the material number
indicated on the name plate.
16
819013-01/05-2012cm (808840-01) · GESTRA AG · Bremen · Printed in Germany
GESTRA AG
Münchener Straße 77
28215 Bremen
Germany
Telefon +49 421 3503-0
Telefax +49 421 3503-393
E-mail info@de.gestra.com
Web www.gestra.de
Agencies all over the world:
www.gestra.de