GESTRA NRS 1-56 User manual
Original Installation &
Operating Manual
Level Switch
NRS 1-56
850697-00-00
EN (USA)
English
2NRS 1-56 - USA - Installation & Operating Manual - 850697-00
Contents
Content of this Manual........................................................................................................................ 4
Scope of supply, product package...................................................................................................... 4
How to use this Manual....................................................................................................................... 5
Illustrations and symbols used........................................................................................................... 5
Hazard symbols in this Manual........................................................................................................... 5
Types of warning ................................................................................................................................. 6
Specialist terms, abbreviations .......................................................................................................... 7
Usage for the intended purpose.......................................................................................................... 8
Applicable directives and standards................................................................................................ 9
Improper use ....................................................................................................................................... 9
Basic safety information ..................................................................................................................... 9
Required personnel qualifications.................................................................................................... 10
Notes on product liability.................................................................................................................. 10
Function ............................................................................................................................................. 10
Technical data ................................................................................................................................... 11
Rating plate, identification NRS 1-56 ............................................................................................... 13
Default factory settings..................................................................................................................... 14
Functional elements and dimensions............................................................................................... 15
Installing the NRS 1-56 level switch................................................................................................. 16
Safety information on the electrical connection.............................................................................. 16
Wiring diagram for the NRS 1-56 level switch................................................................................. 17
Electrical connection......................................................................................................................... 18
Connecting the 24V DC power supply .......................................................................................... 18
Connecting the output contacts..................................................................................................... 18
Connecting the level electrodes .................................................................................................... 18
Connection examples ........................................................................................................................ 19
Fill control - connection of various level electrodes ....................................................................... 19
Discharge control - connection of various level electrodes ............................................................ 20
Changing the equipment settings..................................................................................................... 21
Changing the sensitivity and function............................................................................................ 21
Configuring function and sensitivity .............................................................................................. 22
3NRS 1-56 - USA - Installation & Operating Manual - 850697-00
Contents
Bringing into service - starting, checking switchpoints and function............................................ 23
Bringing into service - operation, testing......................................................................................... 25
System malfunctions......................................................................................................................... 27
Causes ......................................................................................................................................... 27
Indication of system malfunctions................................................................................................. 28
Action against high-frequency interference................................................................................... 28
What to do in the event of system malfunctions.............................................................................. 29
Taking out of service......................................................................................................................... 29
Disposal ............................................................................................................................................. 29
UL components.................................................................................................................................. 29
4NRS 1-56 - USA - Installation & Operating Manual - 850697-00
Content of this Manual
Product:
Level Switch NRS 1-56
First edition:
IOM 850697-00/08-2021cm
You can find the latest Installation & Operating Manuals on our website:
http://www.gestra.com
© 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
■ 1 x level switch NRS 1-56
■ 1 x Installation & Operating Manual
5NRS 1-56 - USA - Installation & Operating Manual - 850697-00
How to use this Manual
This Installation & Operating Manual describes the correct use of the NRS 1-56 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
activities 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
Danger of death from electric shock
Illustrations and symbols used
1. Action to be taken
2.
■ Lists
◆ Bullet points in lists
A Keys to illustrations
Additional
information
Read the relevant
Installation & Operating Manual
6NRS 1-56 - USA - Installation & Operating Manual - 850697-00
Types of warning
DANGERDANGER
Warning of a dangerous situation that results in death or serious injury.
WARNING
Warning of a dangerous situation that may possibly result in death or serious injury.
CAUTIONCAUTION
Warning of a situation that may result in minor or moderate injury.
ATTENTIONATTENTION
Warning of a situation that results in damage to property or the environment.
7NRS 1-56 - USA - Installation & Operating Manual - 850697-00
Specialist terms, abbreviations
Here, we explain some abbreviations, specialist terms, etc., which are used in this Manual.
NRG .. / NRS ..
GESTRA equipment and type designations, see page 8.
SELV
Safety Extra Low Voltage
8NRS 1-56 - USA - Installation & Operating Manual - 850697-00
Usage for the intended purpose
The NRS 1-56 level switch can be used in conjunction with various conductive level electrodes as
an on/off level control system in steam boilers and hot water installations and in condensate and
feedwater tanks. The NRS 1-56 is classified as operating control in accordance with UL60730-1.
The NRS 1-56 level switch also indicates two alarm states, which can be configured as MIN and
MAX.
Overview of possible equipment combinations
Level switch Level electrode Version
NRS 1-56 NRG 1.-52 4-rod electrode
To ensure proper use in all applications, please also read the Installation & Operating
Manuals for the system components used.
■ You will find the latest Installation & Operating Manuals for the system components
listed in the table above on our website:
http://www.gestra.com
9NRS 1-56 - USA - Installation & Operating Manual - 850697-00
Usage for the intended purpose
Applicable directives and standards
The NRS 1-56 level switch 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
Requirements for Automatic Electrical Water Level Sensing Controls
Improper use
There is a danger of death due to explosion if the equipment is used in potentially
explosive atmospheres.
Do not use the equipment in potentially explosive atmospheres.
Do not bring any equipment into service that does not have its own specific rating
plate.
The rating plate indicates the technical features of the equipment.
10 NRS 1-56 - USA - Installation & Operating Manual - 850697-00
Basic safety information
There is a risk of electric shock during work on electrical systems.
■ Always switch off the voltage to the equipment before performing work on the
terminal strips.
■ Check that the plant is not carrying live voltage before commencing work.
Faulty equipment is a danger to plant safety.
■ If the NRS 1-56 level switch does not behave as described on page 23, it may be
faulty.
■ Perform failure analysis.
■ Only replace faulty equipment with identical equipment from GESTRA AG.
Required personnel qualifications
Activity Personnel
Integration in control system Specialist staff Plant designer
Installation/electrical connection/
bringing into service Specialist staff Electrician/installer
Operation Boiler service technician Staff trained by the plant operator
Maintenance work Specialist staff Electrician
Setup work Specialist staff Plant construction
Notes on product liability
The manufacturer cannot accept any liability for damages resulting from improper use of the
equipment.
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