Kobold NGS User manual

Operating Instructions
for
Dual-Magnet Float Switch
Model: NGS

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1. Contents
1. Contents........................................................................................................2
2. Note ..............................................................................................................3
3. Instrument Inspection....................................................................................3
4. Regulation Use..............................................................................................3
5. Operating Principle........................................................................................3
6. ATEX-Marking...............................................................................................4
7. Indications for the Safe EX-use.....................................................................4
8. Mechanical Connection.................................................................................5
9. Electrical Connection ....................................................................................5
10. Maintenance .................................................................................................6
11. Technical Information....................................................................................6
12. Order Codes .................................................................................................7
13. Dimensions ...................................................................................................7
13.1. Accessories .......................................................................................10
14. Declaration of Conformance .......................................................................11
15. ATEX-Certificate .........................................................................................12
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

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2. Note
Please read these operating instructions before unpacking and putting the unit
into operation. Follow the instructions precisely as described herein.
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 EWG-machine guidelines.
3. Instrument Inspection
All 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:
•Dual-Magnet Float Switch model: NGS
•Operating Instructions
4. Regulation Use
Any use of the Dual-Magnet Float Switches, model: NGS, 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.
5. Operating Principle
As the level rises and falls, the inclination of the float is changed causing a
permanent magnet in the float to be deflected. This repels a rotatable opposing
magnet. This forced snap-action-contact effect operates a microswitch
with a plunger. Even very small changes in level can be switched in this way.

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6. ATEX-Marking
The marking in ATEX for the Dual-Magnet Float Switch is as follows:
II 1/2 G EEx dme IIC T6...T2
7. Indications for the Safe EX-use
•Ambient and medium temperature
Temperature class Ambient temperature Max. mediums temperature
T6 -20 °C ... +60 °C +80 °C
T5 -20 °C ... +70 °C +95 °C
T4 -20 °C ... +80 °C +130 °C
T3 -20 °C ... +80 °C +200 °C
T2 -20 °C ... +80 °C +250 °C
•For installation of version NGS-4 _ _ _Ex (with integrated cable) a suitable
junctionbox shall be used.
•The NGS float switch shall be connected to the local EP circuit.
•The NGS float switch has to be provided in series with a circuit breaker as a
short-circuit protection (max. INin accordance with IEC 60127)
•For Tamb >60 °C, a suitable cable shall be used.
Electrical parameters
For connection to an electrical circuit with following maximum values:
UN = 250 V IN = 2,5 A AC12
UN = 220 V IN = 0,3 A DC13
Cable: Cable diameter depends on the mounted cable gland,
Max. 5x2,5mm² cross section
Electric safety: Class 1 according to EN 61010-1
Ingress protection:
NGS-_ _ _ _Ex: IP 65 according to EN 60529
NGS-4 _ _ _Ex: IP 68 according to EN 60529

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8. Mechanical Connection
The float switch is to be installed in such a way that the float is able to move
entirely free without touching the walls, the vessels top, or base. Avoid installation
in turbulent positions: such as inlet valves and agitators.
Please also protect from suspended and ferrite particles that could gather around
the float and disturb the switching process. When installing float switches in
separate housings, suitable valves should be provided since dirty particles must
be drained out from time to time.
For purposes of installation and maintenance, the switch should be installed in an
easily accessible position.
The float switch must be installed with a connecting flange. A seal is enclosed
separately. (Gasket Klingersil C 4500).
For corrosive media, the customer should install an appropriate seal compatible
with the medium being used.
9. Electrical Connection
Attention! Make sure that the voltage values of your system
correspond with the voltage values of the measuring unit.
kábeltípus: NSSHöu-J 5x1,5mm
2
NC
NO
Underwater version
Ex units
Normal units
blue
black black
br ow n
gr .- y el l ow

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10. Maintenance
The measuring unit requires no regular maintenance. Sometimes cleaning of
adhered materials is necessary. Repairs should only be carried out by the
manufacturer.
11. Technical Information
NGS-_1, horizontal mounting
Nominal pressure: 25 bar
Installation position: from side
Differential: fixed, see diagram
NGS-_3, horizontal mounting
Nominal pressure: 16 bar
Installation position: from above
Differential: adjustable
General
Medium temperature: -20 °C to +250 °C*
Ambient temperature: -20 °C to +80 °C*
Min. medium density: > 0.7 kg/dm³
Wetted parts: stainless steel 1.4571
Switch housing: aluminium casting, colour coated
Flat gasket: Klingerit
Process connection: square flange, DIN Flange, 2“ BSP or NPT
Switching element: 1 microswitch with 2 switch contacts,
changeover function
Switch capacity: 250 VAC/10 A
220 VDC/0.6 A
for ex operation: 250 VAC/2.5 A
220 VDC/0.3 A
Electrical connection: M20x1.5
Protection: Standard version:
NGS-2...: IP 65
Submersible version:
NGS-4...: IP 68 (max. 20 m WC)
ATEX-approval: II 1/2 G EEx dme IIC T6...T2
Other approvals: GL-approval
Weight: approx. 2.5 kg
*Temperature designation ATEX-option
Class T6 T5 T4 T3 T2
Process temperature 80 °C 95 °C 130 °C 200 °C 250 °C
Ambient temperature -20...+60 °C -20...+70 °C -20...+80 °C -20...+80 °C -20...+80 °C

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12. Order Codes
Example: NGS-2 1 0 0
Model Housing Installation type Process connection Arm length Approval
NGS-
2 = standard
4 = submersible
(with factory
mounted
cable**)
1 = fixed hysteresis
-standard (side
installation)
-L-arm (inst. from
above)
-Z-arm (side
installation)
0 = 92 mm square flange PN 25
B = BSP 2“
N = 2 NPT
1 = DN 80, PN 40, steel
2 = DN 100, PN 40, steel
5 = DN 80, PN 40, steel 1.4571
6 = DN 100, PN 40, steel 1.4571
0 = 0 mm
5 = 100 mm
6 = 200 mm
7 = 300 mm
8* =L or Z arm,
length
switch point and
installation
position
according to
customer
specification
without =
GL-approval
EX =
ATEX- and
GL- approval
2 = standard
3 = adjustable
hysteresis,
installation from
above
0 = 92 mm square flange PN 25
5 = 1000 mm
6 = 2000 mm
7 = 3000 mm
8* = L arm, length
depending on
customer
specification
*In case of L- or Z arm: please specify dimensions for the switch point (Lsh or Lsl) and the installation position (horizontal
or vertical) in writing
**Please specify cable length in writing
Accessory: counter flange
Model Material
NGS-MFF1 Counter flange, steel 1.7218
NGS-MFF2 Stainless steel, 1.4404
13. Dimensions
Fixed switch hysteresis, side installation
Switching data model NGS-21...
LK = linkage length 0 100 200 300
L = Installation length 202 321 421 521
Lma
x
= Total swing 118 180 234 286
X1 = upper switch point 7 27 45 81
X1 = lower switch point 16 30 47 43
Note: The data apply to water at 20 °C

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Adjustable hysteresis, installation from above
~ 123
92 x 92
9
7
L
1
2
5
L
s
h
(
m
i
n
1
2
5
)
L
s
l
(
m
a
x
[
L
-
1
2
5
]
)
6
23
0
L=Protusion length
Lsh=high switch point
Lsl=low switch point
Process connection: BSP or NPT Square flange
92
92
∅
92/4x13,5
∅

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L arm, installation from above
Z arm, side installation
Submersible Version
TOP
2,5MPa
0,2MPa

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13.1. Accessories
Counter flange NGS-MFF_

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14. Declaration of Conformance
We, KOBOLD Messring GmbH, Hofheim-Ts, Germany, declare under our sole
responsibility that the product:
Dual-Magnet Float Switches Model: NGS
to which this declaration relates is in conformity with the standards noted below:
EN 61010-1:1993/A2:1995
EN 50081-1:1992
EN 50081-2:1993
EN 50082-1: 1997
EN 55022: 1994
IEC 61000-4-2:1995/A1:1998/A2:2000
IEC 61000-4-3:1995/A1:1998/A2:2000
IEC 61000-4-4:1995/A1:2000
IEC 61000-4-5 /A1:2000
IEC 61326: 1997/A1:1998
ATEX-standards
EN 50014: 1997 + A1 + A2
EN 50018: 2000
EN 50028: 1997
EN 50019: 200
Also the following EWG guidelines are fulfilled:
73/23 EWG Low voltage guideline
89/336 EEC EMC Directive
94/9 EG Equipment and Protective systems intended for use in a
potentially Explosive Atmospheres
Hofheim, 30. Dezember 2005
H. Peters M. Wenzel
General Manager Proxy Holder

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15. ATEX-Certificate

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