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NRS 1-51 - USA - Installation & Operating Manual - 

850695-00

How to use this Manual

This Installation & Operating Manual describes the correct use of the NRS 1-51 level switch. It 
applies to persons who integrate this equipment in control systems, install, bring into service,  
operate, maintain and dispose of this equipment. Anyone carrying out the above-mentioned activi-
ties must have read this Installation & Operating Manual and understood its contents.

 

Read this Manual in full and follow all instructions.

 

Please also read the instructions for use of any accessories.

 

The Installation & Operating Manual is part of the product package. Keep it in an easily  
accessible location.

Availability of this Installation & Operating Manual

 

Make sure this Installation & Operating Manual is always available to the operator.

 

If you pass on or sell the equipment to a third party, please also hand over the Installation & 
Operating Manual.

Hazard symbols in this Manual

  Danger zone, dangerous situation

Illustrations and symbols used

1. 

Action to be taken

2. 

 

Lists

 

Bullet points in lists

Keys to illustrations

 Additional 

information

 

Read the relevant  
Installation & Operating Manual

Summary of Contents for NRS 1-51

Page 1: ...Level Switch NRS 1 51 Original Installation Operating Manual 850695 00 EN USA English ...

Page 2: ...8 Improper use 8 Basic safety information 9 Required personnel qualifications 10 Notes on product liability 10 Function 11 Technical data 12 Rating plate identification 13 Factory default settings 14 Dimensions of the NRS 1 51 15 Important notes 16 Safety information 16 Preparing for installation 17 Installation 18 Electrical connection 19 Supply voltage 19 Connecting the level electrode 19 Connec...

Page 3: ...hecking the switchpoint and function 23 Operation alarm and test 24 Fault indications and troubleshooting 24 Important notes 26 Action against high frequency interference 26 Interlock and interlock deactivation 26 Checking switchpoints 26 Taking out of service 27 Disposal 27 UL components 27 ...

Page 4: ... 51 First edition BAN 850695 00 08 2021cm Copyright All rights reserved Any misuse particularly reproduction and dissemination to third parties is not permitted The General Terms Conditions of GESTRA AG apply Scope of supply product package NRS 1 51 1 level switch NRS 1 51 1 Installation Operating Manual ...

Page 5: ...follow all instructions Please also read the instructions for use of any accessories The Installation Operating Manual is part of the product package Keep it in an easily accessible location Availability of this Installation Operating Manual Make sure this Installation Operating Manual is always available to the operator If you pass on or sell the equipment to a third party please also hand over t...

Page 6: ...situation that results in death or serious injury WARNING Warning of a dangerous situation that may possibly result in death or serious injury CAUTION Warning of a situation that may result in minor or moderate injury ATTENTION Warning of a situation that results in damage to property or the environment ...

Page 7: ...t of the plant The operating point describes the operating parameters within which a plant or boiler is operated in its nominal range In a steam boiler for example these parameters would be output pressure and temperature The design data may be a lot more stringent however A boiler that is operated at 145 psi 10 bar and 356 F 180 C may be designed to withstand a pressure of 870 psi 60 bar and a te...

Page 8: ...s or standards below Level electrodes NRG 1 UL 60730 2 15 CAN CSA E60730 2 15 NRG 16 51 NRG 17 51 NRG 19 51 Applicable directives and standards The equipment has been tested and approved for use in the scope governed by the following directives and standards Standards UL 60730 1 and CAN CSA E60730 1 General Requirements for Automatic Electrical Controls UL 60730 2 15 and CAN CSA E60730 2 15 Requir...

Page 9: ...he plant before performing connection work Check that the plant is not carrying live voltage before commencing work Attempts to repair the equipment will cause the plant to become unsafe The NRS 1 51 level switch may only be repaired by the manufacturer GESTRA AG Only replace faulty equipment with identical equipment from GESTRA AG Basic safety information ...

Page 10: ...ought into service by qualified and competent staff Operation Boiler service technician Staff trained by the plant operator Maintenance work Specialist staff Fitting and maintenance work may only be performed by authorized staff who have undergone specific training Refits Specialist staff Persons trained by the plant operator to work with pressure and temperature Notes on product liability The man...

Page 11: ...arm is also triggered if faults occur in the level electrode and or the electrical connection If the level electrode is installed in a level pot outside the boiler make sure the connection pipes are sufficiently large The manufacturer recommends connection pipes of 1 57 in 40 mm for steam and 3 94 in 100 mm for water If smaller connection pipes or fittings are used these shall not be smaller than ...

Page 12: ...ycarbonate front of gray polycarbonate Wire size 1 x AWG12 4 0 mm2 solid or 1 x AWG14 2 5 mm2 stranded with sleeve acc to DIN 46228 or 2 x AWG16 1 4 mm2 stranded with sleeve acc to DIN 46228 Terminal strips can be removed separately Terminal box attachment Mounting clip on support rail TH 35 EN 60715 Electrical safety Pollution degree 2 overvoltage category II according to UL 60730 1 Protection Te...

Page 13: ...el switch Commutateur de niveau 3s Protective Control Class B C acc UL60730 1 10µS cm 2 NRG 1 51 1 2 3 1 3 4 5 16 17 23 24 26 27 NRS 1 51 MAX 0 5A NRS 1 51 Betriebsanleitung beachten See installation instructions Voir instructions de montage GESTRA AG Münchener Str 77 28215 Bremen Made in Germany Tamb 55 C T131 F 24V 20 Alarm extern 24 VDC 100 mA 20 29 21 30 1 2 Input rating 24VDC 7W Ambient tempe...

Page 14: ...he level switch is delivered with the following factory default settings n Off delay 3 s DANGER There is a risk of electric shock during work on electrical systems Switch off the voltage to the plant before you install the equipment Check that the plant is not carrying live voltage before commencing work ...

Page 15: ...l 850695 00 Test Fig 3 Dimensions of the NRS 1 51 1 2 3 6 7 1 Upper terminal strip 2 Lower terminal strip 3 Fastening screws cross recess head screw M3 6 Terminal box 7 Support rail TH 35 EN 60715 Key 3 94 in 100 mm 4 72 in 120 m m 2 91 in 74 mm ...

Page 16: ...fic training Danger The terminal strips of the NRS 1 51 level switch are live during operation There is a risk of serious injury due to electric shock Before working on terminal strips installation removal connection of cables always cut off power to the equipment Attention The rating plate indicates the technical features of the equipment Do not bring into service or operate any equipment that do...

Page 17: ...cal data see page 1612 Do not operate the equipment if the temperature is below freezing At temperatures below freezing use a suitable heat source e g control cabinet heater etc Connect all parts of the plant to a central grounding point to prevent equalizing currents Use UV resistant cable ducts for routing the connecting cable Take further measures to protect the equipment from lightning insects...

Page 18: ... Operating Manual 850695 00 Installation ATTENTION Incorrect installation can lead to malfunctions in the plant or the level electrode The NRS 1 51 level switch snaps onto a TH 35 EN 60715 support rail in a control cabinet Fig 3 7 ...

Page 19: ...als 24 and 26 Provide the output contacts with a slow blow T1A fuse Connecting the control circuit Note n A high level alarm prevents the defined high water level from being exceeded To achieve this the feedwater supply may be cut for example If cutting the feed water supply poses a danger to heating surfaces in the feedwater pre heater the heating must be switched off as well n In the event of an...

Page 20: ...can have a major adverse effect on open and closed loop control systems Connected inductive loads must therefore have interference suppression RC combination as specified by the manufacturer n Connect terminals 24 and 26 with a wire jumper n Route the connecting cables to the level electrodes and the logic unit separately from power lines n Do not use unused terminals as support terminals n If des...

Page 21: ...1 2 3 L 0 5A N Electrical connection Fig 4 Wiring diagram of level switch NRS 1 51 L N 8 9 0 a 0 b 8 Supply voltage 9 Signal output 1 2 for external alarm 24 V DC 100 mA semiconductor output 0 Control circuit input and output a Jumper provided by customer b Level electrode NRG 1 51 CGP Central grounding point in control cabinet Key CGP 9 ...

Page 22: ...e regulations in your country Figure 6 Combination consisting of 1x NRG 1 51 level electrode plus NRS 1 51 level switch as a high level alarm The level switch opens two separate control circuits d Level electrode s NRG 1 51 e Level switch NRS 1 51 f Control circuit Bringing into service There is a risk of electric shock during work on electrical systems Always switch off the voltage to the plant b...

Page 23: ...d indication Error Corrective action Water above high water HW switchpoint according to sight glass but red LED for level electrode 1 is not lit Control circuit closed Electrode rod is too short Replace electrode rod and cut a new one in line with HW switchpoint Ground connection to tank is interrupted Clean sealing surfaces and screw in level electrode with metal sealing ring Do not insu late wit...

Page 24: ...e an alarm Red LED for level electrode 1 flashes Alarm simulation in channel 1 or 2 Off delay in progress signal output 1 closes without a delay Red LED for level electrode 1 lights up Delay has elapsed output contacts open Signal output 1 closed Test is complete If the test is failed replace the level switch Operation alarm and testing Indicators and operation Attention Please check the following...

Page 25: ...error Replace level switch Diagnostic LED 3 flashes Relay error Once the error has been rectified the level switch reverts to normal operation After troubleshooting please switch the supply voltage off and on again after approx 5 s Further fault indications Status Diagnosis Function Next action Error on evaluation of level electrode 1 channel 1 Diagnostic LED 1 and Alarm 1 LED light up Output cont...

Page 26: ...e installation requires an interlock this must be implemented in the downstream control circuit It is important that the interlock is not deactivated when the level switch signals a malfunction to the diagnostic LEDs or the signaling outputs In order to guarantee Class C function with second fault protection in accordance with UL 60730 1 both signaling outputs must be monitored during interlock de...

Page 27: ... Unscrew the fastening screws on the right and left and detach the upper and lower terminal strips Fig 3 1 2 3 n Release the slider holder to detach the level switch and remove it from the support rail Disposal Dispose of the level switch in accordance with statutory waste disposal regulations UL components The NRS 1 51 level switch is registered under XACN E513189 ...

Page 28: ...40 00 GESTRA AG Bremen GESTRA AG Münchener Straße 77 28215 Bremen Germany Tel 49 421 3503 0 Fax 49 421 3503 393 e mail info de gestra com Web www gestra com You can find our authorized agents around the world at www gestra com ...

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