Kobold SMN Operating Manual

Operating Instructions

for

All Metal Flow Switch

Model: SMN

SMN

1. Contents

1. Contents ............................................................................. 2

2. Note .................................................................................... 3

3. Instrument Inspection ......................................................... 3

4. Regulation Use ................................................................... 3

5. Operating Principle ............................................................. 4

6. Use in Hazardous Areas ..................................................... 4

6.1.General 4

6.2.Electrical Contacts 5

6.3.Potential Equalisation 5

7. Mechanical Connection ...................................................... 5

8. Electrical Connection .......................................................... 6

8.1.with Plug Connection 6

8.2.Example for Contact Protective Measures 6

9. Commissioning ................................................................... 7

10. Maintenance and Care ....................................................... 7

11. Technical Information ......................................................... 8

12. Order Codes ....................................................................... 9

13. Dimensions ......................................................................... 9

14. Pressure Loss Diagram .................................................... 10

15. Declaration of the Manufacturer ....................................... 10

16. EU Declaration of Conformance ....................................... 12

Manufactured and sold by:

Kobold Messring GmbH

Nordring 22-24

D-65719 Hofheim

Tel.: [phone]

Fax: [phone]

E-Mail: [e-mail]

Internet: www.kobold.com

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SMN

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 EC-machine guidelines.

as per PED 2014/68/EU

In acc. with Article 4 Paragraph (3), "Sound Engineering Practice", of the
PED 2014/68/EU no CE mark.
Table 8, Pipe, Group 1 dangerous fluids

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:

 All Metal Flow Switch model: SMN
 Operating Instructions

4. Regulation Use

Model SMN instruments monitor liquid flows. Only clean and homogeneous
liquids of low viscosity - against which the instrument materials are resistant ­should be monitored. Large switch-point inaccuracies can occur with highly
viscous media.

Large dirt particles can block the float and thus cause faulty signals. Pieces of
ferrite, deposited on the float (with embedded magnet) can lead to the same
effect (we recommend magnetic filters).

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SMN

5. Operating Principle

The KOBOLD model SMN flow switch is used when extremely low flow switch
points are required in combination with minimum pressure loss at high flow rates.

The flow switch operates on the well-known float principle.
An orifice float with an integrated circular magnet moves within a cylindrical flow
tube in the direction of the flow and against a spring.

The magnetic field of the float activates a reed contact which is mounted on the
outside of the instrument in a sliding protective casing. Due to the special
construction of the float and flow tube only a low flow is required to raise the float
and hence to activate the reed contact. If the flow rate increases further and the
float reaches the top of its travel an additional flow path opens allowing high flow
rates without a significant increase in the pressure loss.

6. Use in Hazardous Areas

6.1. General

The All Metal Flow Switch does not have a potential igniting source of his own as
a mechanical operating resource; it does not get any identification according

to the guideline 94/9/EC ("ATEX 100a”).

The add-on control contacts can under application of EN 60079-14 be used as a
“simple operator” (simple electrical equipment) without other marking in
intrinsically safe equipment. The following limit values for the switching contact
should not be exceeded: U = 30 VDC, I = 100 mA, P = 1,2 W. It does not get any
identification according to the ATEX-guideline.

The units can be used as follows:

a) In the Zone 2 (Gas-Ex, Cat. 3G) into explosion group of IIA, IIB and IIC
b) In the Zone 22 (Dust-Ex, Category 3D) at non-conductive dusts with a

minimum igniting energy of > 3 mJ
c) In the Zone 1 (Gas-Ex, Cat. 2G) into explosion group of IIA, IIB and IIC
d) In the Zone 21 (Dust-Ex, Category 2D) at non-conductive dusts with a

minimum igniting energy of > 3 mJ

The Flow Switch is filled completely with medium in the normal operation. Zone 2
or zone 1 conditions may be obtained for a short time.

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