Kobold NST User manual

Operating Instructions
for
Float Switch
Model: NST

NST
page 2 NST K06/0422
1. Contents
1.Contents ........................................................................................................ 2
2.Note .............................................................................................................. 3
3.Instrument Inspection .................................................................................... 3
4.Regulation Use ............................................................................................. 3
5.Operating Principle ........................................................................................ 4
6.Mechanical Connection ................................................................................. 4
7.Electrical Connection .................................................................................... 4
7.1General ................................................................................................ 4
7.2Connection example ............................................................................ 5
8.Technical Information .................................................................................... 6
9.Order Codes ................................................................................................. 6
10.Dimensions ................................................................................................... 7
11.EU Declaration of Conformance ................................................................... 8
Manufactured and sold by:
Kobold Messring GmbH
Nordring 22-24
D-65719 Hofheim
Tel.: [phone]
Fax: [phone]
E-Mail: [email protected]
Internet: www.kobold.com

NST
NST K06/0422 page 3
2. Note
Please read these operating instructions before unpacking and putting the unit
into operation. Follow the instructions precisely as described herein.
The instruction manuals on our website www.kobold.com are always for currently
manufactured version of our products. Due to technical changes, the instruction
manuals available online may not always correspond to the product version you
have purchased. If you need an instruction manual that corresponds to the
purchased product version, you can request it from us free of charge by email
([email protected]) in PDF format, specifying the relevant invoice number and
serial number. If you wish, the operating instructions can also be sent to you by
post in paper form against an applicable postage fee.
The devices are only to be used, maintained and serviced by persons familiar
with these operating instructions and in accordance with local regulations
applying to Health & Safety and prevention of accidents.
When used in machines, the measuring unit should be used only when the
machines fulfil the EC-machine guidelines.
3. Instrument Inspection
Instruments are inspected before shipping and sent out in perfect condition.
Should damage to a device be visible, we recommend a thorough inspection of
the delivery packaging. In case of damage, please inform your parcel service /
forwarding agent immediately, since they are responsible for damages during
transit.
Scope of delivery:
The standard delivery includes:
 Float Switch model: NST
4. Regulation Use
Any use of the Float Switch, model: NST, which exceeds the manufacturer’s
specification may invalidate its warranty. Therefore, any resulting damage is not
the responsibility of the manufacturer. The user assumes all risk for such usage.

NST
page 4 NST K06/0422
5. Operating Principle
The float comprises a hollow cylinder or a ball with integrated Reed contact or
microswitch.
The switch is supplied as a changeover contact; it can be connected as a N/O
contact or N/C contact as an option. The contact switches when the liquid passes
above or below the horizontal float position.
The switch point is set either by the side installation of the switch at the desired
height or by clamping the cable. In case of installation from the top, switchpoint
will stabilize itself through the bading weights.
6. Mechanical Connection
Before installation:
 Remove the transport locks and make sure that there are no more packaging
parts on the device.
 Check whether the maximum allowable operating pressures and temperatures
of the device are not exceeded (see technical data).
 If possible, should already be in accordance with the mechanical installation,
check whether the connection fitting is tight.
As contact protection, concerning protection against contact, we recommend our
contact protection relay MSR.
Installation
 From the inside via G ½ threaded (only type NSTB)
 Externally by means of G 2 fitting
7. Electrical Connection
7.1 General
Attention! Make sure that the maximum voltage power values of
the level switch are not exceeded.
With rising levels: black/ blue: NO
black/ brown: NC

NST
NST K06/0422 page 5
7.2 Connection example

NST
page 6 NST K06/0422
8. Technical Information
Typ NST…: PTFE
Float material: PTFE
Bellows: PTFE (model NST-B only)
Cable: Model NST-A: 2 m FEP cable
Model NST-B: 2 m silicone or FEP cable
Max. pressure: 1 bar
Max. temperature: 150 °C (TPK cable)
Medium density: > 0,79 kg/ dm³
Contact: Reedcontact, connectable as N/O or N/C
Switch capacity: 4...250 VAC/DC
1 mA...1 A, 60 VA
Switch hysteresis: ca. 100 mm
Switch angle: +20° / -20°
Protection: IP 68
9. Order Codes
Example: NST-AW 02 FEP
Model Description
NST-
NST-Anschl. R50A
NST-Anschl. R50B
AW 02 FEP = standard-design, 2 m FEP-cable
BW 02 FEP = PTFE bellows, 2 m FEP-cable
BW 02 SIL = PTFE bellows, 2 m SIL-cable
PTFE cable gland, G 2, for standard design
PTFE cable
g
land, G 2, for bellows

NST
NST K06/0422 page 7
10. Dimensions

NST
page 8 NST K06/0422
11. EU Declaration of Conformance
We, KOBOLD Messring GmbH, Hofheim-Ts, Germany, declare under our sole
responsibility that the product:
Float Switch Model: NST
to which this declaration relates is in conformity with the standards noted below:
EN 61010-1:2010 + A1:2019 + A1:2019/AC:2019 Safety requirements for
electrical equipment for measurement, control and laboratory use - Part 1:
General requirements
EN 61326-1: 2013
Electrical equipment for measurement, control and laboratory use - EMC
requirements - Part 1: General requirements
Also, the following EC guidelines are fulfilled:
2014/30/EU EMC Directive
2014/35/EU Low Voltage Directive
2011/65/EU RoHS (category 9)
2015/863/EU Delegated Directive (RoHS III)
Hofheim, 21 April 2022
H. Volz M. Wenzel
General Manager Proxy Holder