background image

E N

E n g l i s h

Level Switch

NRS 1-50

For 

TWO

 Electrodes

Original Installation Instructions

818953-08

Summary of Contents for NRS 1-50

Page 1: ...E N English Level Switch NRS 1 50 For TWO Electrodes Original Installation Instructions 818953 08 ...

Page 2: ...ty Integrity Level SIL for safety related systems 7 Technical Data NRS 1 50 8 Example name plate marking 10 Dimensions and Functional Elements NRS 1 50 11 Key 11 Installation Mounting level switch NRS 1 50 12 Electrical Connection Supply voltage 12 Connection of level electrode 12 Connection of safety circuit 12 Connection of logic unit standby input 12 Connection for signal output 13 Tools 13 Wir...

Page 3: ...and adjustors 19 Troubleshooting Indication diagnosis and remedy 19 Checking Level Electrodes Measuring voltage across level electrode 21 Key 21 Emergency operation Emergency operation for water level limiter 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 Decla...

Page 4: ...ctrode 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 signal outputs for external signalling devi...

Page 5: ...eas Safety note 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 Incorrect installation wiring or commis sioning can endanger the safety of your plant Danger The terminal st...

Page 6: ...gnose 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 SIL Architecture Lifetime a Proof Test Interval a General 3 1oo2 20 20 SFF PFDav PFHav λ DU Level switch NRS 1 50 in conjunction with one or two level electrode s 90 ...

Page 7: ...ly for the whole safety related 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 PFDsys The Low demand mode 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 ...

Page 8: ...nations according to manufacturer s specification to ensure interference suppression Signal output 2 volt free outputs for instantaneous external signalling 24 VDC max 100 mA semiconductor output 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 2 two pole code switches for setting the number of electrode...

Page 9: ...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 Technical Data continued ...

Page 10: ...n 4 Power consumption 5 Protection 6 Operating data max ambient temperature 7 Supply voltage 8 Protection class 9 Wiring diagram 0 Type approval no a Material number serial number b Manufacturer c Type approval d Disposal note Optional data e Measuring range in µS cm f Measuring range in ppm g Relay protection h Note on functional safety i Marking for limiter or monitor j Field for adjusted limit ...

Page 11: ...ng on off level electrode 1 2 5 Code switch for switching on off level electrode 1 2 6 Enclosure 7 Supporting rail type TH 35 EN 60715 Key The code switches are accessible after removing the lower terminal strip The terminal strips can be unplugged after undoing the right and the left fixing screws 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 1 1 ON ON 2 2 1 27 16 17 18 19 20 21 22 23 24 25 26 28 29 30 Fig...

Page 12: ...exceed 36 V DC Connection of logic unit standby input Note n 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 Supply voltage Provide the level switch NRS 1 50 with an external semi delay fuse 0 5...

Page 13: ...nnect to terminals 6 7 14 15 standby input 1 2 must be certified to have at least double or reinforced isolation according to EN 61010 1 EN 60730 1 EN 60950 1 or EN 62368 1 safe isolation between the standby inputs and the live parts of the installation that are not supplied with safety extra low voltage SELV Attention n Provide the level switch NRS 1 50 with an external semi delay fuse 0 5 A n Co...

Page 14: ...m for level switch NRS 1 50 8 Supply voltage 9 Signal output 1 2 for external alarm 24 V DC 100 mA semiconductor output 0 Safety circuit input and output a Wire link on site when used as water level limiter acc to EN 12952 EN 12953 b Stand by input 1 2 24 V DC for connecting the logic unit SRL 6 50 c Level electrode NRG 1 50 NRG 1 11 or NRG 16 36 CEP Central earthing point in control cabinet Key C...

Page 15: ... e e f f d d e f e f d d g e f f Fig 8 Fig 9 Fig 10 Fig 11 Fig 12 Fig 13 Electrical Connection continued Schematic representations of arrangements e e d Level electrode s NRG 1 50 e Level switch NRS 1 50 Key f Safety circuit g Level switch NRS 1 50 for low level pre alarm ...

Page 16: ...the type of pressurization For electrically heated steam boilers one water level limiter is sufficient To meet the plant operator s demand for a higher level of availability of the steam boiler plant two or three independent equipment combinations NRG 1 50 NRS 1 50 can be installed in the steam boiler Further applications in accordance with national sets of regulations Fig 10 Combination consistin...

Page 17: ... 5 set to OFF Note n If only one level electrode is switched on only the LEDs for power and alarm of the corresponding channels will be illuminated If only one electrode is used for operation e g in case of emergency operation change the settings as follows n Switch off mains voltage n Unscrew the right and left fixing screws 3 and remove the lower terminal strip 2 Fig 6 n Depending on which elect...

Page 18: ...ts Status and indication Fault Remedy Sightglass indicates level below switchtpoint low water LW red LEDs for level electrodes 1 2 not illuminated Safety circuit closed Electrode rod s is are too long Cut electrode rod s to the length dictated by the switchpoint LW If installed inside the boiler Up per vent hole in protection tube does not exist or is obstructed Check installation of level electro...

Page 19: ...r level electrode 1 2 are flashing Alarm simulated in channel 1 or 2 De energizing delay is running Signal outputs 1 2 are closed instantaneously Red LEDs for level electrode 1 2 illuminated Delay time has elapsed output contacts open Signal outputs 1 2 are closed Test finished Operation Alarm and Test Indicators and adjustors Attention Before carrying out the fault diagnosis please check Supply v...

Page 20: ... LED 3 flashing Interference voltage causing malfunction boiler earth without PE Provide screen and earthing connect boiler with PE LED alarm 1 and 2 and Diagnosis LED 3 illuminated Press and hold down key 1 or 2 Diagnosis LED 1 flashing Malfunction in processor stand by fault Observe operating instructions for the logic unit SRL Replace level switch Diagnosis LED 2 flashing Internal voltage fault...

Page 21: ...11 U11 12 Fig 15 c c c NRG 16 36 2 1 4 3 NRG 1 50 NRG 1 11 NRG 1 50 NRG 1 11 b b Checking Level Electrodes Measuring voltage across level electrode Note The self checking routine of the level switch NRS 1 50 reduces U2 4 10 12 to 0 Volt if executed cyclically U2 4 10 12 2 U2 4 10 12 2 b Stand by input 1 2 24 V DC for connecting the logic unit SRL c Level electrode NRG 1 50 NRG 1 11 NRG 16 36 CEP C...

Page 22: ...Depending on which electrode shall be deactivated set S1 or S2 of code switches 4 and 5 to ON n Attach lower terminal strip and fasten fixing screws n Apply mains voltage equipment is re started Attention n Record the beginning of emergency operation in the boiler log n An installation operating in emergency mode has to be constantly supervised n Immediately replace faulty level electrode n Record...

Page 23: ...m of the equipment and take the equipment off the supporting rail Decommissioning replacing level switch Disposal For the disposal of the level switch observe the pertinent legal regulations concerning waste disposal 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 s...

Page 24: ...s The Declaration of Conformity can be found online at www gestra com and associated certificates can be requested from 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 com Note that Declarations of Conformity and associated certificates lose their validity if equipment is modified without prior consultation w...

Page 25: ...25 NRS 1 50 For TWO Electrodes Installation Instructions 818953 08 For your notes ...

Page 26: ...26 NRS 1 50 For TWO Electrodes Installation Instructions 818953 08 For your notes ...

Page 27: ...27 NRS 1 50 For TWO Electrodes Installation Instructions 818953 08 For your notes ...

Page 28: ...Straße 77 28215 Bremen Germany Telefon 49 421 3503 0 Telefax 49 421 3503 393 E mail info de gestra com Web www gestra com Agencies all over the world www gestra com UK Importer GESTRA UK Ltd Unit 1 Sopwith Park Royce Close West Portway Business Park Andover Hampshire SP10 3TS United Kingdom ...

Reviews: