Flowserve NRS1-9 User Manual

NRS 1-9

Installation Instructions 810831-00

Water-Level Limiter / Controller NRS 1-9

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Contents

Page

Important Notes

Usage for the intended purpose .................................................................................... 7

Safety note.....................................................................................................................7

Danger ........................................................................................................................... 7

Explanatory Notes

Scope of supply ............................................................................................................. 8

Description .....................................................................................................................8

Function ......................................................................................................................... 8

Design ............................................................................................................................ 9

Technical data ............................................................................................................... 9

Installation

NRS 1-9 ....................................................................................................................... 10

Example of installation ................................................................................................ 15

Wiring

Wiring diagram......................................................................................................... 3, 10

Basic Adjustments

Change-over for sensitivity .......................................................................................... 11

Commissioning

Check wiring ................................................................................................................ 11

Apply power ................................................................................................................. 11

Performance Tests

Low level limiter ........................................................................................................... 12

High level limiter .......................................................................................................... 12

Water level controller ................................................................................................... 12

Annex

Fault finding list for troubleshooting ............................................................................ 13

Declaration of conformity............................................................................................. 14

2

Wiring Diagram

NRS 1-9

Fig. 1

NRG 16-36

3

Functional Elements / Dimensions

A

1
2

MAX 55 °C

Fig. 2

95

158

3

MAX 95 %

4
5
6

A

C

BF

D

D

4

D

Fig. 3

37.5

75

E

120

5

Fig. 4

Functional Elements

Fig. 5

G

5

Key

A

Cover screws

B

Cover

C

Base

D

Cable entry

E

Mounting clip

F

Hole for wall mounting

G

Code switch for setting sensitivity

1

LED “High level alarm”

2

Switch “Test 2 / Inspection”

3

LED “Low level alarm”

4

Test button “Test 1”

5

LED “Pump ON”

6

LED “Power”

6

Important Notes

Usage for the intended purpose

Water level controllers and water level limiters serve as safety equipment in
installations requiring official approval. Use switching controller/limiter NRS 1-9 only
for monitoring and indicating liquid levels.

Safety Note

Installation must only be performed by qualified staff.
Qualified staff are those persons who – through adequate training in electrical

engineering, the use and application of safety equipment in accordance with regula­tions concerning electrical safety systems, and first aid & accident prevention –
have achieved a recognised level of competence appropriate to the installation and
commissioning of this critical safety device.

Danger

The terminal strip of the NRS 1-9 is live during operation. This presents
the danger of electric shock. Cut off power supply before fixing or
removing the housing cover.

7

Explanatory Notes

Scope of supply

NRS 1-9

1 Water level controller/water level limiter (plug-in unit for installation in control

cabinets)

1 Installation manual

Description

Self-monitoring water level controller & limiter with automatic self-testing routine
designed for use in conjunction with level electrode NRG 16-36. This equipment
combination controls the water level, detects the max. allowable water level
(high level alarm) and the min. allowable water level (low level alarm).

Application in compliance with the German regulations for use in steam and
hot-water plants according to TRD 602 and TRD 604, sheets 1 and 2.

Function

The switching controller NRS 1-9 features a two channel circuit and is provided with
a self-monitoring and routine testing function in accordance with DIN 57116/VDE

0116. The two channels are designed to monitor the operation of each other
(redundancy). The periodic self-checking logic unit checks the integrity of the cable
between the electrode and the switching controller, and the two channel circuits for
malfunction.
Unless it finds a fault, this internal test does not interfere with the output contacts of
the controller and therefore the boiler operation is not interrupted.
A manual test push button is also provided. When the push button “TEST 1” is
pressed, it simulates a fault in the electrode. There is also a toggle switch “TEST 2/
Inspection” for checking the function of the self-checking circuitry. The output
contact relays of the switching controller are of the normally closed type and will
therefore signal alarm condition in the event of mains failure.

The switching controller can signal the following four operating conditions:

■ Normal operation (feedwater control)

■ Alarm (high water level)

■ Alarm (low water level)

■ Alarm (fault in switching controller or level electrode)

A green LED indicates power ON. Low water level alarm or malfunction of the low
water level limiter system is indicated by the two red LEDs. The failure of one
channel (loss of redundancy) is signalled by the lighting up of one red LED. The
other green LED indicates feedwater pump is running. High water level alarm is
signalled by another red LED.

The use of SMART combination electrode NRG 16-36 in conjunction with switching
controller NRS 1-9 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.

8

Explanatory Notes – continued –

Design

NRS 1-9b:

Plug-in unit in plastic case for snapping onto a 35 mm rail (TS 35 x 15 according to
DIN EN 50022-35) or for installation in control

Technical Data

Type approval no.

TÜV · WR/WB · 99-370

Input

8 connections for one level electrode NRG 16-36, PN 40

Output contacts
For level limiter part:

Two volt-free relay contacts

For level controller part:

One volt-free working contact for feedwater on-off control.
One volt-free relay contact for high level alarm.
Contact material silver, hard gold plated.
Max. contact rating with switching voltages of 24 V, 115 V and 230 V a.c.:
4 A resistive, 0.75 A inductive at cos ϕ 0.5
Max. contact rating with switching voltage of 24 V d.c.: 4 A

Delay of response

The low water level alarm signal is factory set to react after a time delay of
1 or 3 seconds (up to 25 sec. delay is possible).
The controller as well as the high water level alarm signal is factory set to react after
a time delay of 2 seconds.

Sensitivity

Range 1: 10 µS/cm at 25°C
Range 2: 0.5 µS/cm at 25°C
The selection of the above range is done via a code switch.

Indicators and adjustors

One green LED “Power”, two LEDs “Low level alarm”, one test button “TEST 1”, one
toggle switch “TEST 2/INSPECTION”, one LED “Feedwater control on”, one LED
“High level alarm” and one four-pole code switch.

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;
24 V d. c. supply is also possible with the inverter type URN-1.

Protection

IP 20 in accordance with DIN 40050

Admissible ambient temperature

0 to 55 °C

Case materials

Base: ABS plastic, black. Cover: polystyrene, highly shock resistant, stone grey.

Weight

0.6 kg
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Installation

NRS 1-9

On supporting rail

1. Snap switching controller onto supporting rail.

2. Loosen cover screws and unplug cover from its base .

3. Select cable entry and remove corresponding seal.

A B

D

C

On mounting panel

1. Loosen cover screws and unplug cover from its base .

2. Unscrew mounting clip .

3. Drill the hole marked in the base to 4.3 mm diameter.

F

4. Select cable entry and remove corresponding seal.

A

E

D

B

C

5. Fasten base with two screws M4 onto mounting panel.

Tools

■ Screwdriver (5.5/100)

Wiring

NRS 1-9

Use four-core overall screened cable, e. g. IY(ST)Y 2 x 2 x 0.9 or LIYCY 4 x 0.5 mm².
Max. cable length 250 m.

Connect terminal strip in accordance with wiring diagram, fig. 1

Wiring Diagram

see page 3

Attention

■ To protect the switching contacts fuse circuit with 2.5 A (slow blow fuse)

or according to TRD regulations (1.0 A for 72 hrs operation).

■ The screen must not make any other electrical contact.

10

Note

■ Connect screen only to terminals 16 and 21 of the switching controller.

■ The mains voltage is indicated on the name plate.

■ When switching off inductive loads, voltage spikes are produced that

may impair the operation of control and measuring systems. Inductive
loads should be provided with commercial arc suppressor RC
combinations, e. g. 0.1 µF/100 W.

Wiring – continued –

Tools

■ Screwdriver for slotted screws, size 2.5, completely insulated according to

VDE 0680.

Basic Adjustments

Change-over for sensitivity

The switching controller can be set to two different sensitivities. For this purpose a
code switch consisting of four individual switches is provided on the rear of the
controller.

Range 1: Sensitivity from 10 µS/cm (factory setting)
Range 2: Sensitivity from 0.5 µS/cm

1. Cut off power supply to switching controller.

2. Loosen cover screws and unplug cover from its base , fig. 1.

A

3. Move all four individual switches of the code switch to the desired range using

B

G

a small screwdriver, fig. 5.

Tools

■ Screwdriver for slotted screws, size 2.5, completely insulated according to

VDE 0680.

C

Commissioning

Check wiring

Check whether switching controller NRS 1-9 and the associated electrode
NRG 16-36 are wired in accordance with wiring diagram, fig. 1.

Apply power

Apply mains voltage. The green LED lights up, fig. 2.

6

11

Performance Tests

Low-level limiter

1. Check length of electrode tip (see installation instructions for NRG 16-36).

2. When switching on the mains voltage the green LED should light permanently,

fig. 2.

3. Completely open valves of water-level gauge glass on steam boiler.

4. Fill boiler with feedwater (2 cm above required min. level).

5. Decrease level in boiler until the level falls below min. level. After the response
delay the two red LEDs must light up.

3

6. A low-level alarm can be simulated by pushing the button “TEST I” whilst the
electrode tip is submerged. Push the button until the response delay has expired.
Both red LEDs must light up.

3

7. To check the function of the checking circuitry of the switching controller proceed
as follows: Operate switch “TEST II/INSPECTION” in the direction of the arrow
with the electrode tip submerged. After max. two minutes the two red LEDs
should signal low-level alarm.
The button “TEST I” must not be operated during this test nor must the level

4

fall below the low level mark.
After the test return switch into its original position. After the response delay the
two red LEDs must extinguish.

3

High-level limiter

1. Check length of electrode tip (see installation instructions for NRG 16-36).

2. Completely open valves of water-level gauge glass on steam boiler.

3. Fill boiler with feedwater until the level exceeds the required max. level.

After the response delay of 2 sec. the red LED must light up, fig. 2.

4. Decrease level in the boiler until the level falls below high level, the red LED
must extinguish.

6

4

2

3

1

1

Water level controller

1. Check length of electrode tips (see installation instructions for NRG 16-36).

2. Lower water level in boiler until electrode tip “2” (lower switch point) is completely
exposed, fig. 1.

3. The green led must light up, fig. 2.

5

Simultaneously the switching function for feedwater control (PUMP ON)
is released.

4. When the water level reaches electrode tip “3” (upper switch point), LED must

5

extinguish. Simultaneously the switching function for feedwater control (PUMP
OFF) is released.

12

Annex

Danger

The terminal strip of the NRS 1-9 is live during operation. This presents
the danger of electric shock. Cut off power supply before fixing or
removing the housing cover.

Fault finding list for troubleshooting

Fault:

Remedy:

Fault:

Remedy:

Fault:

Remedy:

Fault:

Remedy:

The switching controller signals low-level alarm before the level in the
boiler has fallen below the low level mark.

Check length of low-water level electrode tip. Measure the conductivity of
the process or boiler water and compare the values obtained with the
marking on the name plate. Check correct wiring of switching controller
and electrode in accordance with wiring diagram, fig. 1.

After raising the water level above the low-level mark, the red LEDs

3

are not extinguished or only after quite a considerable period.
Check whether a vent hole has been provided in the protection tube. If the

electrode is fitted in an external chamber, check position of isolating
valves.

One or both red LED(s) light up without the level having fallen below

3

the low-level mark.
This means electronic failure within the switching controller, i. e. failure of

one or both channels. Replace switching controller.

The switching controller signals high-level alarm before the level in the
boiler has reached the high level mark.

Check length of high water level electrode tip. Check whether the
electrode tip has contact with the chamber/protection tube or other boiler
internals. Check correct wiring of level switch and electrode in accordance
with wiring diagram, fig. 1.

Fault:

After decreasing the water level below the high-level mark, the red LED
is not extinguished or only extinguishes after quite a considerable period.

Remedy:

Check whether a vent hole has been provided in the protection tube. If the
electrode is fitted in an external chamber, check position of isolating
valves.

If faults occur that are not listed above please contact our subsidiary or agency in
your country.

4

13

Annex – continued –

Declaration of conformity

We hereby declare that the equipment NRS 1-9 conforms to the following European
guidelines:

■ LV guideline 73/23/eec version 93/68eec

■ EMC guideline 89/336/eec version 93/68/eec

which are based on the following harmonized standards:

■ LV standard EN 60947-5-1: 1991

■ EMC standard EN 50 081-2, EN 50 082-2

This declaration is no longer valid if modifications are made to the equipment without
consultation with us.

Bremen, 1st January 2000

GESTRA GmbH

Dr. Anno Krautwald

Key

A

Cover screws

B

Cover

C

Base

F

Hole for wall mounting

H

Mounting clip

I

Support rail TS 35 x 15 to DIN EN 50022-35

Dipl.-Ing. Uwe Bledschun

(Academically qualified engineer)

14

Example of Installation

B

CH

MAX 55°C

MAX 95%

Fig. 6

I

A

F

F

Fig. 7

15

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®

GESTRA GmbH

P. O. Box 10 54 60, D-28054 Bremen, Münchener Str. 77, D-28215 Bremen
Telephone [phone], Fax [phone] - 393
E-Mail [e-mail], Internet www.gestra.de

A Unit of Flowserve Corporation

810831-00/903c · © 2000 GESTRA GmbH · Bremen · Printed in Germany

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