Flowserve NRS1-8 User Manual
GESTRA
GESTRA Steam Systems
NRS 1-8
Installation Instructions 818612-00
Level Switch NRS 1-8
1
2
Contents
Page
Important Notes
Usage for the intended purpose ..............................................................................................................4
Safety note .............................................................................................................................................4
Danger ...................................................................................................................................................4
ATEX (Atmosphère Explosible) .................................................................................................................4
Explanatory Notes
Scope of supply ......................................................................................................................................4
Description .............................................................................................................................................4
Function .................................................................................................................................................5
System components ...............................................................................................................................5
Design ....................................................................................................................................................5
Technical Data
NRS 1-8
..................................................................................................................................................6
Corrosion resistance ...............................................................................................................................7
Name plate / marking .............................................................................................................................7
Dimensions .............................................................................................................................................8
Design
NRS 1-8..................................................................................................................................................9
Key ....................................................................................................................................................... 11
Functional Elements
NRS 1-8................................................................................................................................................10
Key ....................................................................................................................................................... 11
Installation
NRS 1-8................................................................................................................................................12
Attention ............................................................................................................................................... 12
Tools .....................................................................................................................................................12
Key ...................................................................................................................................................... 12
Examples of installation ........................................................................................................................13
Wiring
NRS 1-8
................................................................................................................................................14
Voltage table .........................................................................................................................................14
Attention ............................................................................................................................................... 14
Note .....................................................................................................................................................14
Tools .....................................................................................................................................................14
Wiring diagram .....................................................................................................................................15
Contents – continued –
Page
Commissioning
Checking wiring ....................................................................................................................................16
Apply mains voltage..............................................................................................................................16
Performance test
High-level limiter ..................................................................................................................................16
Operation
Water-level alarm .................................................................................................................................17
Note .....................................................................................................................................................17
Operational Malfunctions
Fault-finding list for troubleshooting malfunctions .................................................................................17
Decommissioning
Danger .................................................................................................................................................18
Disposal................................................................................................................................................18
Annex
Declaration of Conformity CE ................................................................................................................19
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4
Important Notes
Usage for the intended purpose
Use level switch NRS 1-8 only in conjunction with level electrodes NRG 16-12, NRG 17-12, NRG 19-12
for level control (high level alarm).
Safety note
The equipment must only be installed 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.
Danger
The terminal strip of the NRS 1-8 is live during operation. This presents the danger
of electric shock!
Cut off power supply before attaching or detaching the housing lid and the terminal
strips of the equipment.
ATEX (Atmosphère Explosible)
The equipment constitutes a simple item of electrical equipment as defined in DIN EN 50020 section
5.4. According to the European Directive ATEX 94/9/EC the equipment may only be used in potentially
explosive atmosphers if it is provided with approved Zener barriers.
Applicable in Ex zones 1, 2 (1999/92/EC). The equipment does not bear a CE marking. The suitability of
the Zener barriers is certified in a separate document.
Explanatory Notes
Scope of supply
NRS 1-8
1 Level switch NRS 1-8
1 Installation manual
Description
Self-monitoring high-level alarm with periodic self-checking routine, designed for use in conjunction
with level electrodes NRG 16-12, PN 40, NRG 17-12, PN 63, NRG 19-12, PN 160. The equipment
combination detects the max. water level (high level alarm).
Application in steam and (pressurized) hot water boilers in accordance with TRD 602 and TRD 604
sheet 1 and sheet 2 as well as EN 12952 and EN 12953.
Explanatory Notes – continued –
Function
The level switch NRS 1-8 is a two-channel unit provided with an automatic self-checking circuitry in
accordance with DIN VDE 0116 prEN 50156 (directives for protection circuits). The self-checking is
effected periodically. The test includes the checking of the cable between electrode and level switch and
of the self-checking circuitry (redundancy). The output relays are not influenced by the internal tests.
In addition to this self-checking routine, the level switch can also be tested manually by pushing the
button “Test 1”, simulating a defect in the electrode. The test switch “Test 2/Inspection” is provided for
checking the function of the checking circuitry.
As the circuit of the relay contacts of the level switch is normally closed, alarm will also be signalled in
the event of a mains failure.
The level switch can signal the following three operating conditions:
n Normal operation (correct level)
n Alarm (high level)
n Alarm (malfunction in level switch or electrode)
The green LED indicates power supply. The high level or malfunction alarms are indicated by two red
LEDs. The failure of one channel (loss of redundancy) is signalled by the illumination of a single red LED.
The combination of electrode NRG 16-12, NRG 17-12, NRG 19-12 and level switch NRS 1-8 provides
fail-safe protection against a first fault, i. e. the system will still continue to provide the safety function
even after the occurrence of a first fault.
System components
NRG 16-12
Level electrode NRG 16-12, PN 40
NRG 17-12
Level electrode NRG 17-12, PN 63
NRG 19-12
Level electrode NRG 19-12, PN 160
Design
NRS 1-8
Plug-in unit in plastic case for installation in control cabinets. The terminals in the case are accessible
after loosening two screws and unplugging the unit from its base.
To avoid confusion with other plug-in units of the GESTRA range, inserts are fitted in the bases so that
only the correct unit may be plugged into each base.
The plug-in unit may be snapped onto a 35 mm supporting rail or screwed into position on a mounting
panel.
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6
Technical Data
NRS 1-8
Type approval no.
09 - 91 - 0112
Input
Four terminals for the connection of one level electrode
NRG 16-12, PN 40
NRG 17-12, PN 63
NRG 19-12, PN 160
Output
Two volt-free relay contacts (mounted in series in the case of design “b").
Max. contact rating: 250 V, 300 W, 3 A resistive with a life of 5 x 10
inductive with a life of 2 x 10
6
switching cycles. Contact material silver, hard-gold plated.
Delay of response
Default factory setting: 3 s
(Up to 25 s possible after prior consultation with TÜV)
Sensitivity
10 µS/cm at 25 °C when used in conjunction with level electrode without measuring surface
extension (cell constant C = 0.3).
0.5 μS/cm at 25 °C when used in conjunction with level electrode with measuring surface
extension (cell constant C = 0.13) – see data sheet “NRG 16-12”.
Indicators and adjustors
2 LEDs “Alarm”, 1 LED “Power”, 1 button “TEST 1”,
1 switch “TEST 2 / INSPECTION”.
Mains supply
230 V +/- 10 %, 50/60 Hz (please state voltage when ordering).
Special voltage: 115 V +/- 10 %, 50/60 Hz or 24 V +/- 10 %, 50/60 Hz.
The ancillary unit URN 1 can be used for 24 V d. c. supply.
Power consumption
5 VA
Protection
NRS 1-8 IP 40 to EN 60529
Admissible ambient temperature
0 °C to 55 °C
Case materials
Base: Noryl SE 1-GFN 2 UL 94 VO, black
Cover: R-ABS UL 94 VO, stone grey
Weight
Approx. 0.6 kg
5
switching cycles of 0.35 A
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