Flowserve NRS 1-50 User Manual

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GESTRA

GESTRA Steam Systems

NRS 1-50

For ONE Electrode

Installation Instructions 818987-00

Level Switch NRS 1-50

English

Contents

Page

Application

Usage for the intended purpose ..............................................................................................................4

Function .................................................................................................................................................4

Directives and Standards

Pressure Equipment Directive (PED) 97/23/EC ........................................................................................

Functional Safety acc. to IEC 61508 ........................................................................................................

VdTÜV Bulletin “Wasserstand 100” (= Water Level 100) ..........................................................................

Approvals for Marine Applications ........................................................................................................... 5

LV (Low Voltage) Directive and EMC (Electromagnetic Compatibility) .......................................................5

ATEX (Atmosphère Explosible) .................................................................................................................5

Functional Safety acc. to IEC 61508

Safety characteristics of the subsystem NRG 1...-50 / NRS 1-50 .............................................................

Terms and abbreviations .........................................................................................................................6

Determination of the Safety Integrity Level (SIL) for safety-related systems .............................................7

Technical Data

NRS 1-50

Name plate / marking ...........................................................................................................................10

Dimensions and Functional Elements

NRS 1-50..............................................................................................................................................11

Important Notes

Safety note ...........................................................................................................................................12

Scope of supply ....................................................................................................................................12

Installation

..........................................................................................................................................8 – 9

5 5 5

Mounting level switch NRS 1-50 ........................................................................................................... 13

Contents - continued -

Page

Electrical Connection

Mains supply ........................................................................................................................................13

Connection of level electrode ................................................................................................................ 13

Connection of safety circuit ...................................................................................................................13

Connection of logic unit (standby input).................................................................................................13

Connection for signal output .................................................................................................................13

Tools .....................................................................................................................................................14

Wiring diagram for level switch NRS 1-50 .............................................................................................15

Schematic representations of arrangements .........................................................................................16

Explanatory notes to schematic respresentations .................................................................................. 17

Basic Settings

Factory setting ......................................................................................................................................18

Commissioning Procedure

Checking switchpoint and function .......................................................................................................19

Operation, Alarm and Test

Indicators and adjustors ........................................................................................................................20

Troubleshooting

Indication, diagnosis and remedy ..................................................................................................20 – 21

Checking level electrode

Measuring voltage across level electrode ..............................................................................................22

Further Notes

Action against high frequency interference ...........................................................................................23

Interlock and interlock deactivation .......................................................................................................23

Checking the switchpoints .................................................................................................................... 23

Decommissioning / replacing level switch .............................................................................................23

Disposal................................................................................................................................................23

Note on the Declaration of Conformity / Declaration by the Manufacturer .......................................23

Application

Usage for the intended purpose

The level switch NRS 1-50 is used in conjunction with level electrode NRG 1...-.. to limit the water level in steam boilers and (pressurised) hot-water plants. Water level limiters switch off the heating when the water level falls below the set minimum level (low water).

Depending on the speciﬁed directives or standards, the level switch NRS 1-50 is intended to be used in combination with the following level electrodes:

Level electrode NRG 1...-..

PED Pressure Equipment Directive 97/23/EC + Functional Safety IEC 61508 SIL 3

VdTÜV Bulletin “Wasserstand 100” (= Water Level 100)

Marine applications GL/LR Directives

Function

The level switch NRS 1-50 is designed for different electrical conductivities of the boiler water and for connecting one level electrode.

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. This switchpoint is determined by the length of the electrode rod (level electrode NRG 1...-50, NRG 1...-11, NRG 16-36).

After the de-energizing delay has elapsed, the two output contacts of the level switch will open the safety circuit for the heating. The switching-off of the heating is interlocked in the external safety circuit and can only be deactivated when the level electrode enters the water again.

In addition two signalling contacts for external signalling devices close instantaneously. An alarm will also be raised if a malfunction occurs in the level electrode and/or the electrical connec-

tion. If the level electrode is installed in an isolatable level pot outside the boiler, make sure that the con-

necting lines are rinsed regularly. During the rinsing process the water level cannot be measured in the level pot for 5 minutes. The level switch therefore bypasses the level electrode and monitors the rinsing and bypass time (standby input, controlled by the logic unit SRL 6-50).

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.

An automatic self-testing routine monitors the safety functions in the level switch and the level electrode. In the event of a malfunction the safety circuit opens instantaneously and switches the heating off.

Alarm and error messages are indicated by LEDs and an alarm can be simulated by pressing the test button.

NRG 16-50 NRG 17-50 NRG 19-50 NRG 111-50 NRG 16-36

NRG 16-50 NRG 16-11

NRG 16-50S NRG 16-11S NRG 16-38S NRG 16-39S

NRG 17-50 NRG 17-11

NRG 19-50 NRG 19-11

NRG 111-50 NRG 111-11

NRG 16-36

Directives and Standards

Pressure Equipment Directive (PED) 97/23/EC

Water level limiters are safety accessories as deﬁned in the Pressure Equipment Directive (PED). The level switch NRS 1-50 in conjunction with level electrode NRG 1...-50 and NRG 16-36 is EC type approved according to EN 12952/EN 12953. These Directives state, among other things, the require ments made on limiting systems and equipment for steam boiler plants and (pressurised) hot-water installations.

Functional Safety acc. to IEC 61508

The level switch NRS 1-50 is certiﬁed acc. to IEC 61508 only if used in combination with level elec trode NRG 1...-50 / NRG 16-36 . This standard describes the functional safety of safety-related electri cal/electronic/programmable electronic systems.

The equipment combination NRG 1...-50 or NRG 16-36 + NRS 1-50 corresponds to a type B subsys tem with Safety Integrity Level (SIL) 3.

VdTÜV Bulletin “Wasserstand 100” (= Water Level 100)

The level switch NRS 1-50 in conjunction with the level electrodes NRG 1...-50, NRG 1...-11 and NRG 16-36 is type approved according to the VdTÜV Bulletin “Water Level 100”. The VdTÜV Bulletin “Wasserstand (= Water Level) 100” speciﬁes the requirements made on water level control and limiting equipment for boilers.

Approvals for Marine Applications

The level switch NRS 1-50 in conjunction with level electrodes NRG 16-50S/NRG 16-11S/NRG 16-38S and NRG 16-39S is approved for marine applications. We can present approvals issued by Germanischer LLoyd and Lloyd’s Register.

LV (Low Voltage) Directive and EMC (Electromagnetic Compatibility)

The level switch NRS 1-50 meets the requirements of the Low Voltage Directive 2006/95/EC and the EMC Directive 2004/108/EC.

ATEX (Atmosphère Explosible)

According to the European Directive 94/9/EC the level switch NRS 1-50 must explosive areas.

not be used in potentially

Note

The level electrodes NRG 1...-50, NRG 1...-11 and NRG 16-36 are simple items of elec trical equipment as speciﬁed in EN 60079-11 section 5.7. According to the European Directive 94/9/EC 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. The suitability of the Zener barriers is certiﬁed in a separate document. Note that the requirements of the IEC 61508 are not met if the NRG 1...-50, NRG 1...-11 and NRG 16-36 + Zener barriers + NRS 1-50 are interconnected!

Functional Safety acc. to IEC 61508

Safety characteristics of the subsystem NRG 1...-50 / NRS 1-50

The level switch NRS 1-50 is certiﬁed acc. to IEC 61508 if used in combination with level electrode NRG

1...-50 / NRG 16-36. The combination NRG 1...-50 / NRG 16-36 / NRS 1-50 corresponds to a type B subsystem with Safety

Integrity Level (SIL) 3. Type B means that the behaviour under fault conditions of the used components cannot be completely determined. The functional safety of the equipment combination refers to the detection and evaluation of the water level and, as a consequence, the contact position of the output relays.

The design of the equipment combination NRG 1...-50 / NRG 16-36 / NRS 1-50 corresponds to the ar chitecture 1oo2 D. This architecture consists of two channels that detect and diagnose faults in each other. If a fault is detected, the equipment combination NRG 1...-50 / NRG 16-36 / NRS 1-50 will go to the safe state, which means that the contacts of both output relays will open the safety circuit.

Safety characteristics

General 3 1oo2 D 20 20

Level switch NRS 1-50 alone 98.54 % 1.18 x 10

Level switch NRS 1-50 in conjunction with

one level electrode NRG 1...-50, NRG 16-36

Fig. 1

Terms and abbreviations

Terms

Abbreviations

Safety Integrity Level

SIL

Lifetime (a) Functional safety: Lifetime in years

Safe Failure Fraction

SFF

Probability Failure per Demand

(Low Demand) PFD

Probability Failure per Hour

PFH

Classification of the Safety Integrity Level acc. to IEC 61508

Percentage of failures without the potential to put the safety-related system into a dangerous state

Average probability of failure on demand for low demand mode (once a year)

Probability of failure per hour

Failure rate for all dangerous undetected failures (per hour) of a channel of a subsystem

Fig. 2

SIL Architecture

SFF PFD

98.17 % 1.69 x 10

-4

Description

Lifetime

(a)

PFH

3.73 x 10

4.54 x 10

Proof Test

Interval (a)

-8

7.33 x 10

9.33 x 10

-8

Functional safety acc. to IEC 61508 - continued -

Determination of the Safety Integrity Level (SIL) for safety-related systems

Level electrode, level switch and actuators (auxiliary contactor in safety circuit) are subsystems and together constitute a safety-related system that executes a safety function.

The speciﬁcation of the safety-related characteristics Fig. 1 refers to the level electrode and the level switch including the output contacts. The actuator (e. g. an auxiliary contactor in the safety circuit) is installation speciﬁc and, according to IEC 61508, must be considered separately for the whole safetyrelated system.

Table Fig. 3 shows the dependence of the Safety Integrity Level (SIL) on the average probability of failure on demand of a safety function for the whole safety-related system (PFD is here considered for a water level limiter, which means that the frequency of demands for operation of the safety-related system is no greater than one per year.

). The “Low demand mode”

sys

Low demand mode PFD

-5

... < 10

-4

... < 10

-3

... < 10

-2

... < 10

-4

-3

-2

-1

≥ 10 ≥ 10 ≥ 10 ≥ 10

sys

Safety Integrity Level

(SIL)

4 3 2 1

Fig. 3

The table in Fig. 4 indicates the attainable Safety Integrity Level (SIL) as a function of the Safe Failure Fraction (SFF) and the Hardware Fault Tolerance (HFT) for safety-related systems.

Hardware Fault Tolerance (HFT) for type B

0 1 2

SIL 1 SIL 2 SIL 1 SIL 2 SIL 2

SIL 3 SIL 4 90 % – < 99 %

SIL 3 60 % – < 90 %

SIL 3 SIL 4 SIL 4 ≥ 99 %

Safe Failure Fraction

(SFF)

< 60 %

Fig. 4

Technical Data

NRS 1-50

Supply: Mains voltage

24 VDC +/– 20%, 0.3 A or 100 – 240 VAC +10/–15 %, 47 – 63 Hz, 0.2 A External fuse

0.5 A (semi-delay)

Power consumption

7 VA Response sensitivity (Electrical conductivity of water at 25 °C)

> 0,5 ... < 1000 µS/cm or > 10 ... < 10000 µS/cm

Inputs: Connection of level electrode

1 input for level electrode NRG 1...-50, NRG 1...-11, NRG 16-36, 4 poles, with screen.

Stand-by input

1 volt-free input, 24 V DC, for monitoring the purging and bypass time. Max. bypass time: 5 minutes.

Outputs: Safety circuit

2 volt-free make contacts, 24 V DC - 250 V AC, max. 6 A (resistive/inductive), Contact material AgNi. Delay of response: 3 seconds, 15 sec. for marine applications. Provide inductive loads with RC combinations according to manufacturer's speciﬁcation to ensure interference suppression.

Signal output

2 volt-free outputs for instantaneous external signalling, 24 - 230 V AC/DC, max. 100 mA.

Indicators and adjustors

2 buttons for test and diagnosis, 2 red/green LEDs for indicating the operating mode and alarm. 3 red LEDs for diagnosis.

Housing Housing material: base: polycarbonate, black; front: polycarbonate, grey. Conductor size: 1 x 4.0 mm 1 x 2.5 mm 2 x 1.4 mm

per stranded wire with sleeve to DIN 46228 or

per stranded wire with sleeve to DIN 46228;

solid per wire or

terminal strips can be detached Fixing of housing: Mounting clip on supporting rail TH 35, EN 60715

Electrical safety

Degree of contamination: 2, overvoltage category III to EN 61010-01. Protection

Housing: IP 40 to EN 60529 Terminal strip: IP 20 to EN 60529

Weight

approx. 0.5 kg

Technical Data - continued -

NRS 1-50 - continued -

Further conditions: Ambient temperature

when system is switched on: 0 ° ... 55 °C during operation: -10 ... 55 °C

Transport temperature

-20 ... +80 °C (< 100 hours), defrosting time of the de-energized equipment before it can be put into operation: 24 hours.

Storage temperature

-20 ... +70 °C, defrosting time of the de-energized equipment before it can be put into operation: 24 hours.

Relative humidity max. 95%, no moisture condensation

Site altitude max. 2000 m

Approvals EC Prototype approval PED Pressure Equipment Directive 97/23/EC EN 12952-11, EN 12953-09: Requirements made on limiting equipment for boilers.

Functional safety IEC 61508: Functional safety of safety-related SIL 3 electrical/electronic/programmable electronic systems

TÜV type approval VdTÜV Bulletin “Wasserstand 100” (= Water Level 100): Requirements made on water level limiting & control equipment.

Type approval no. TÜV.SWB.XX-422 (see nameplate)

Marine applications Regulations of Germanischer Lloyd, Lloyd’s Register

Technical Data - continued -

Wasserstandbegrenzer Water level limiter Limiteur de niveau d’eau

NRS 1 - 50

Tamb = 55°C (131°F)

IP 40 (IP20)

7 VA

Betriebsanleitung beachten

See installation instructions

Voir instructions de montage

Alarm extern

24-230 VAC/DC

100 mA

0525

250V

T 2,0A

TÜV . SWB . 09-422

GESTRAAG

Münchener Str. 77 D-28215 Bremen

Niveauschalter Level switch Commutateur de niveau

N L

3sec.

6 7

SRL

Funktionale Sicherheit Functional safety Sécurité fonctionnelle IEC 61508 SIL 3

10 µS/cm

NRG 1...-50

232426

NRS 1-50

24V =

+ / - 20%

MIN

(+)

M 0,5A

(-)

Name plate / marking

Safety

note

Type designation

Mains voltage/ Protection

Ambient temperature / sensitivity

Wiring

diagram

Manufac-

turer

Fig. 5

Wire link, provided on site

Safety circuit

Fuse, provided on site

Approvals

Disposal note

Serial number

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

2716 17 18 19 20 21 22 23 24 25 26 28 29 30

Dimensions and Functional Elements

NRS 1-50

100

Fig. 6

Key

1 Upper terminal strip 2 Lower terminal strip 3 Fixing screws (cross recess head screws M3) 4 Enclosure 5 Supporting rail type TH 35, EN 60715

120

Important Notes

Safety note

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.

Danger

The terminal strips of the equipment are live during operation. This presents the danger of electric shock! Always cut off power supply to the equipment before mounting, removing or connecting the terminal strips!

Attention

The name plate speciﬁes the technical features of the equipment. Note that any piece of equipment without its speciﬁc name plate must neither be commissioned nor operated.

Scope of supply

NRS 1-50

1 Level switch NRS 1-50 1 Installation manual

Installation

Mounting level switch NRS 1-50

The level switch NRS 1-50 is clipped onto the support rail type TH 35, EN 60715 in the control cabinet.

Fig. 6 5

Electrical Connection

Mains supply

Fuse the level switch NRS 1-50 with an external semi-delay fuse 0.5 A.

Connection of level electrode

To connect the level electrode use screened multi-core control cable with a min. conductor size

0.5 mm2, e.g. LiYCY 4 x 0.5 mm2. Max. length 100 m with an electrical conductivity of the boiler water > 10 μS/cm at 25°C.

Max. length 30 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. 5.

Connect screen only to terminal 5.

Connection of safety circuit

Connect the safety circuit for the heating to terminals 23, 24 and 26, 27. Wenn used as water level limiter according to TRD, EN 12952 / EN 12953 connect the output contacts of the two monitoring channels by adding a wire link between the terminals 24 and 26.

Fuse the output contacts with a 2 A or 1 A (for 72 hours operation acc. to TRD 604) slow-blow fuse.

Note

n In the event of an alarm the level switch NRS 1-50 does not interlock automatically.

If an interlocking function in the installation is required, the follow-up circuit (safety circuit) must be equipped with an interlock. The circuitry must meet the requirements of the EN 50156.

Connection of logic unit (standby input)

For connecting the level switch with the logic unit use a control cable, e. g. 2 x 0.5 mm

The control voltage must not exceed 36 V DC.

Connection for signal output

A signal output for the connection of further external signalling equipment is allocated to each monitoring channel in the level switch, max. load 100 mA. For connecting the level switch with the logic unit use a control cable, e. g. 2 x 0.5 mm

. In the event of an alarm or error message the signal outputs

(terminals 20, 21 and 29, 30) open instantaneously.

Electrical Connection - continued -

Danger

n For the supply of the level switch NRS 1-50 with 24 V DC use a safety extra-low volt-

age (SELV) power supply unit that must be electrically isolated from dangerous contact voltages and must meet at least the requirements on double or reinforced isolation acc. to DIN EN 50178 or DIN EN 61010-1 or DIN EN 60730-1 or DIN EN 60950 (safe isolation).

n Any item of equipment that you want to connect to terminals 6, 7 (standby input) must

be certiﬁed to have at least double or reinforced isolation according to DIN EN 50178 or DIN EN 61010-1 or DIN EN 60730-1 or DIN EN 60950 (safe electrical isolation) between the standby inputs, the signal outputs and the live parts of the installation that are not supplied with safety extra-low voltage (SELV).

Attention

n Fuse the level switch NRS 1-50 with an external semi-delay fuse 0.5 A. n Connect screen of electrode wire only to terminal 5. n To protect the switching contacts provide the safety circuit with a slow-blow fuse 2 A

or 1.0 A (for 72 hrs. operation acc. to TRD 604).

n When switching off inductive loads, voltage spikes are produced that may impair

the operation of control and measuring systems. Connected inductive loads must be provided with suppressors such as RC combinations as speciﬁed by the manufacturer.

n When used as water level limiter according to TRD, EN 12952 / EN 12953 connect

terminals 24 and 26 by adding a wire link.

n Install connecting lines to level electrode and logic unit separated from power cables. n Do not use unused terminals as support point terminals.

Tools

n Screwdriver for slotted screws, size 3.5 x 100 mm, completely insulated according to VDE 0680-1.

2716

1 2 3 4 5 6 7 8

17 18 19 20 21 22 23 249251026

11 12281329143015

NRG 1...-50

NRG 16-36

M 0,5A

(+)+(-)

N NL L

Electrical Connection - continued -

Wiring diagram for level switch NRS 1-50

L N (+) (–)

+ –

Fig. 7

Key

8 Mains supply 9 Signal output 1 / 2 for external alarm 24-230 V AC/DC 100 mA 0 Safety circuit, input and output a Wire link, on site, when used as water level limiter acc. to TRD, EN 12952 / EN 12953 b Stand-by input, 24 V DC, for connecting the logic unit SRL 6-50 c Level electrode NRG 1...-50, NRG 1...-11 or NRG 16-36

Electrical Connection - continued -

Schematic representations of arrangements

Fig. 8

Fig. 9

Fig. 10 Fig. 11

Key

d Level electrode NRG 1...-50 e Level switch NRS 1-50

f Safety circuit g Level switch NRS 1-50 for low-level pre-alarm

Electrical Connection - continued -

Explanatory notes to schematic respresentations

Steam boiler plants and (pressurized) hot-water installations according to TRD 604, EN 12952-07 / EN 12953-06, 72 h operation

Fig. 8

Combination consisting of 1 level electrode NRG 1...-50 and 1 level switch NRS 1-50 as water level limiter. Functional safety IEC 61508, SIL 3. For operation according to TRD 604, EN 12952-07 / EN 12953-06 (72 hours), two independent and separate water level limiters must be used. Hot water installations require two independent and separate water level limiters. For this purpose one equipment combination NRG 1...-50/NRS 1-50 shall be installed in the hot-water boiler and the second one in the pressure maintaining vessel, the expansion tank or the like (depending on the type of pressurization). For electrically heated steam boilers one water level limiter is sufﬁcient.

Further applications in accordance with national sets of regulations Fig. 9

Combination consisting of 1 level electrode NRG 1...-50 and 1 level switch NRS 1-50 as water level limiter. The level switch opens two separate safety circuits. Functional safety IEC 61508, SIL 3.

Fig. 10

Combination consisting of 1 level electrode NRG 1...-50 and 1 level switch NRS 1-50 as water level limiter and 1 level electrode NRG 1...-50 / 1 level switch NRS 1-50 as low-level pre-alarm. Functional safety IEC 61508, SIL 3.

Fig. 11

Combination consisting of 2 level electrodes NRG 1...-50 and 2 level switches NRS 1-50 as water level limiter. The level switch opens two separate safety circuits. Functional safety IEC 61508, SIL 3.

Basic Settings

Factory setting

Level Switch NRS 1-50

The level switch features the following factory set default values:

n De-energizing delay: 3 sec., 15 sec. for marine applications.

Commissioning Procedure

Danger

Commissioning - continued -

Checking switchpoint and function

Level electrode 1

Test & diagnosis button

LED alarm 1 /

Fig. 12

Activity Indication Function

Apply mains voltage.

Raise water in boiler until the switchpoint “low water level (LW)” is ecxeeded. Level electrode enters the water.

Lower water level until it is below the switchpoint “low water level (LW)”. Level electrode is exposed.

Status and indication Fault Remedy

Sightglass indicates level below switchtpoint “low water (LW)”, red LED for level electrode 1 not illuminated. Safety circuit closed.

Water level sufﬁcient. Red LED for level electrode 1 is illuminated. Safety circuit is open.

operating mode

Diagnosis LED

Start

All LEDs are illuminated.

All LEDs are illuminated for more than 10 sec.

Green LED for level electrode 1 is illuminated

Checking switchpoint and function

Red LED for level electrode 1 is ﬂashing

Red LED for level electrode 1 is illuminated

Possible installation faults

Electrode rod is too long.

If installed inside the boiler: Upper vent hole in protection tube does not exist or is obstructed.

The electrode rod is too short.

The earth connection to the vessel is interrupted.

Electrical conductivity of the boiler water too low.

Upper vent hole ﬂooded.

LED alarm 2 / operating mode

System is being started and tested, this takes approx. 10 sec. Output contacts are open. Signal outputs 1 / 2 are closed.

System malfunction. Possible causes: Faulty power supply, level switch defective.

Output contacts are closed. Signal outputs 1 / 2 open.

De-energizing delay is running. Signal outputs 1 / 2 are closed instantaneously.

Delay time has elapsed, output contacts open. Signal outputs 1 / 2 are closed.

Cut electrode rod to the length dictated by the switchpoint LW.

Check installation of level electrode. Make sure that the level in the protection tube corresponds to the actual water level.

Replace electrode rod and cut new rod to the length dictated by the switchpoint LW.

Clean seating surfaces and screw in level electrode with metallic joint ring. Do not insulate the electrode with hemp or PTFE tape!

Set response sensitivity of the level switch to

0.5 μS/cm. Check installation of level electrode. Make sure

that the level in the protection tube corresponds to the actual water level.

Test & diagnosis button

Operation, Alarm and Test

Indicators and adjustors

Level electrode 1

Test & diagnosis button

LED alarm 1 / operating mode

Fig. 12

Activity Indication Function

Level electrode submerged.

Level electrode exposed, level below low water level (LW).

During operation: Press and hold down key 1 until the end of the test, level switch must function as if there were an alarm.

Green LED for level electrode 1 is illuminated

Red LED for level electrode 1 is ﬂashing

Red LED for level electrode 1 is illuminated

Red LED for level electrode 1 is ﬂashing

Red LED for level electrode 1 is illuminated

Diagnosis LED

Operation

Alarm

Test channel 1 and 2

LED alarm 2 / operating mode

Output contacts are closed. Signal outputs 1 / 2 open.

De-energizing delay is running. Signal outputs 1 / 2 are closed instantaneously.

Delay time has elapsed, output contacts open. Signal outputs 1 / 2 are closed.

Alarm simulated in channel 1 or 2. De-energizing delay is running. Signal outputs 1 / 2 are closed instantaneously.

Delay time has elapsed, output contacts open. Signal outputs 1 / 2 are closed. Test ﬁnished.

Test & diagnosis button

Troubleshooting

Indication, diagnosis and remedy

Attention

Before carrying out the fault diagnosis please check: Mains supply:

Is the level switch supplied with the mains voltage speciﬁed on the name plate? Wiring:

Is the wiring in accordance with the wiring diagram and the relevant schematic representation of arrangement?

Troubleshooting - continued -

Indication, diagnosis and remedy - continued -

Fault indication

Status Diagnosis Function Next activity

Faulty evaluation of level electrode 1, channel 1

Malfunction in level switch detected.

Display 1 and activity Display 2 Fault Remedy

LED alarm 1 and diagnosis LED 1 illuminated. Press and hold down key 1.

LED alarm 1 and 2 and Diagnosis LED 3 illuminated. Press and hold down key 1 or 2.

Once the fault is eliminated, the level switch returns to normal operation. After elimination of the fault switch off the mains voltage and switch it on again after approx. 5 sec.

Diagnosis LED 1 and LED alarm 1 illuminated.

Diagnosis LED 3 and LED alarm 1 and 2 illuminated.

Diagnosis LED 1 ﬂashing.

Diagnosis LED 2 ﬂashing.

Diagnosis LED 3 ﬂashing.

Diagnosis LED 1 ﬂashing.

Diagnosis LED 2 ﬂashing.

Diagnosis LED 3 ﬂashing.

Malfunction in level electrode 1, malfunction in level switch, faulty wiring, faulty measuring voltage.

Malfunction in level electrode 1, malfunction in level switch, faulty wiring.

Interference voltage causing malfunction, boiler earth without PE

Malfunction in processor, stand-by fault.

Internal voltage fault.

Malfunction in relay.

Output contacts are opened instantaneously. Signal output 1 closes instantaneously.

Output contacts are opened instantaneously. Signal outputs 1 and 2 are closed instantaneously.

Diagnosis

- check wiring,

- measure electrode voltages,

- clean and, if necessary exchange level electrode,

- exchange level switch.

Provide screen and earthing, connect boiler with PE.

Observe operating instructions for the logic unit SRL. Replace level switch.

Replace level switch.

next: Press key 1.

next: Press key 1 or key 2.

If faults occur that are not listed above or cannot be corrected, please contact our service centre or authorized agency in your country.

Checking level electrode

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

NRG 1...-50

NRG 16-36

Measuring voltage across level electrode

Measure the electrode voltage in order to check whether the level electrode is immersed or if there is a malfunction. Please observe Fig. 15.

1-2

1-⊥

exposed

1-2

≥

1-2

⊥-2

⊥-1

1-2

≈ 0.7 V

85 Hz !

1-2

⊥-2

⊥-1

immersed

+ –

2-⊥

Malfunction (immersed/alarm)

≤

⊥

Fig. 13

Key

b Stand-by input 1, 24 V DC, for connecting the logic unit SRL c Level electrode NRG 1...-50, NRG 1...-11, NRG 16-36

Note

The self-checking routine of the level switch NRS 1-50 reduces U

if executed cyclically.

to 0 Volt,

1-2

Further Notes

Action against high frequency interference

Should sporadic failures occur in installations susceptible to faults (e. g. malfunctions due to out-ofphase switching operations) we recommend the following actions in order to suppress interferences:

n Provide inductive loads with RC combinations according to manufacturer's speciﬁcation to ensure

interference suppression.

n Increase the distance to sources of interference. n Check screens and shields. n HF interference suppression by means of hinged-shell ferrite rings.

Interlock and interlock deactivation

In the event of an alarm the level switch NRS 1-50 does not interlock automatically. If a lock function is required by the installation it must be provided in the follow-up circuitry (safety

circuit). The circuitry must meet the requirements of the EN 50156.

Checking the switchpoints

To check the switchpoint “Low water (LW)” you have to lower the water level. When the water level falls below the electrode tip, the level switch must activate an alarm and the safety circuit must open as soon as the de-energizing time delay has elapsed. The switching-off of the heating is interlocked in the safety circuit and can only be deactivated when the level electrode enters the water again. Always check the switchpoint when commissioning the equipment, after replacing the level electrode and at regular intervals, e. g. every year.

Decommissioning / replacing level switch

n Switch off mains voltage and cut off power supply to the equipment. n Unscrew the right and left ﬁxing screws 3 and remove the upper and lower terminal strips 1 2,

Fig. 6.

n Release the white ﬁxing slide at the bottom of the equipment and take the equipment off the sup-

porting rail.

Disposal

For the disposal of the levels switch observe the pertinent legal regulations concerning waste disposal.

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./de/documents or can be requested from us.

Agencies all over the world:

www.gestra.de

GESTRA

España

GESTRA ESPAÑOLA S.A.

Luis Cabrera, 86-88 E-28002 Madrid Tel. 0034 91 / 5 15 20 32 Fax 0034 91 / 4 13 67 47; 5 15 20 36 E-mail: aromero@ﬂowserve.com

Great Britain

Flowserve GB Limited

Abex Road Newbury, Berkshire RG14 5EY Tel. 0044 16 35 / 46 99 90 Fax 0044 16 35 / 3 60 34 E-mail: gestraukinfo@ﬂowserve.com

Italia

Flowserve S.p.A.

Flow Control Division Via Prealpi, 30 l-20032 Cormano (MI) Tel. 0039 02 / 66 32 51 Fax 0039 02 / 66 32 55 60 E-mail: infoitaly@ﬂowserve.com

Polska

GESTRA POLONIA Spolka z.o.o.

Ul. Schuberta 104 PL - 80-172 Gdansk Tel. 0048 58 / 3 06 10 - 02 0048 58 / 3 06 10 - 10 Fax 0048 58 / 3 06 33 00 E-mail: gestra@gestra.pl

Portugal

Flowserve Portuguesa, Lda.

Av. Dr. Antunes Guimarães, 1159 Porto 4100-082 Tel. 00351 22 / 6 19 87 70 Fax 00351 22 / 6 10 75 75 E-mail: jtavares@ﬂowserve.com

USA

Flowserve GESTRA U.S.

2341 Ampere Drive Louisville, KY 40299 Tel. 001 502 / 267-2205 FaxL 001 502 / 266-5397 E-mail: FCD-Gestra-USA@ﬂowserve.com

GESTRA AG

P. O. Box 10 54 60, D-28054 Bremen Münchener Str. 77, D-28215 Bremen Telephone 0049 (0) 421 / 35 03 - 0 Fax 0049 (0) 421 / 35 03 - 393 E-Mail gestra.ag@ﬂowserve.com Internet www.gestra.de

818987-00/12-2009cm (808835-00) · GESTRA AG · Bremen · Printed in Germany

Flowserve NRS 1-50 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual