Kobold MS Series User manual

Operating Instructions
for
Magnetic Level Switches
Model: MS Series

MS series
page 2 DT0493
1. Contents
1. Contents .......................................................................................................... 2
2. Note ................................................................................................................ 3
3. Instrument Inspection ...................................................................................... 3
4. Regulation Use ............................................................................................... 4
5. Float designs ................................................................................................... 4
6. Operating Principle ......................................................................................... 6
7. Mechanical Connection ................................................................................... 6
8. Area of application .......................................................................................... 6
9. Maintenance ................................................................................................... 6
10. Technical Data .............................................................................................. 7
11. Electrical Information ..................................................................................... 8
12. Safety Instructions ...................................................................................... 11
Area of validity............................................................................................. 11
Guidelines. .................................................................................................. 11
Protection against ESD ( electro static discharges ) ................................... 11
Chemical resistance .................................................................................... 12
Maintenance and repairs ............................................................................. 12
Storage ....................................................................................................... 12
13. Installation in hazardous zone ..................................................................... 12
14. Electrical connection in ATEX zone ............................................................ 13
15. ATEX Label Description .............................................................................. 13
16. Disposal ...................................................................................................... 14
17. Declaration of conformity ATEX Ex ia ......................................................... 15
18. EU Declaration of Conformity ...................................................................... 16
19. UK Declaration of Conformity ...................................................................... 17
20. ATEX Certified ........................................................................................... 18
21. Notes ........................................................................................................... 23
Manufactured by:
Kobold Mesura S.L.U.
Avda. Conflent 68 nave 15
08915 Badalona
Tel.: [phone]
Fax: [phone]
E-Mail: [email protected]
Internet: www.kobold.com
Edition: Dec. 2022

MS series
page 3 DT0493
2. Note
Please read these operating instructions before unpacking and putting the unit in
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 correspond 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:
 Magnetic Level Switches for Liquids model: MS-...
 Operating Instruction
All parts falling under the standard scope of delivery are properly assembled
within the unit.

MS series
page 4 DT0493
4. Regulation Use
Magnetic Level Switches are employed for monitoring and control of liquid-levels
in boilers and containers. There are innumerable and diverse applications that
require these Magnetic Level Switches to be made according to customers'
specific requirements.
Attention! These units should not be installed in the vicinity of
strong magnetic fields, since this can impair their intended
functionality.
5. Float designs
Model Form Materials
Float
Outside
 [mm]
Height
[mm]
Bore
Hole 
[mm]
Min. Liquid
Density
[kg/dm³]
Max.
Temperature
°C
Nominal
Pressure
[bar] at
20 °C
MS05 Cylinder
hollow PP 42 40 14 > 0.5 80°C 3 bar
MS061)
Cylinder
solid
material
PP 40 20 14 > 0.9 90 °C 100 bar
MS07 Cylinder
hollow PVC-U 42 40 14 > 0.65 55 °C 3 bar
MS10 Ball
hollow
St. steel
1.4404 52 52 15 > 0.6 150°C 30 bar
1) For MS06 model. one float is required for each switch point.
For all other floats two contacts can be operated with one float.

MS series
page 5 DT0493
Supplementary devices:
1. Contact protection relays
We recommend the use of contact protection relays in conjunction with sealed
contacts.
Contact protection relays have the following advantages:
 No contact overloads arising from sparking and high currents, which can,
for example, be caused by self-induced e.m.f.`s when switching solenoid
valves.
 Float switches are electrically isolated from the high voltage power supply
system.
 Protection for persons who come into contact with liquids according to
VDE 0100.
 Standard models:
Mod. MSR 10 1 channel, 1 changeover
Mod. MSR 20 2 channels, 2 changeover
Mod. MSR 11 2 channels, 1 changeover bistable
 Atex models:
Mod. KFD2-SR2-Ex1.W 1 channel, 1 relay output, supply 24 VDC
Mod. KFA6-SR2-Ex1.W 1 channel, 1 relay output, supply 230 VAC
Mod. KFD2-SR2-Ex2.W 2 channel, 2 relay output, supply 24 VDC
Mod. KFA6-SR2-Ex2.W 2 channel, 2 relay output, supply 230 VAC
2. Damping tube for agitated liquids
Float switches with damping tube for agitated or dirty liquids can be supplied upon
request.
3. Temperature monitoring
Float switches with integrated temperature switch, fixed switch point between
60 °C and 150 °C upon request.
Option: Pt 100 available
4. Mounting instructions
Float switches can also be fitted in the bottom for vessels.
Attention: The contact operation is then reversed.

MS series
page 6 DT0493
6. Operating Principle
Kobold magnetic float switches are fitted with a hermetically sealed contact which
is situated in the tube.
The float sliding on the tube contains a ring magnet whose magnetic field
switches the sealed contact in a non-contacting fashion. The sealed contacts are
available as N/O, N/C or changeover contacts.
The float sliding up and down on the liquid is the only moving part in the Kobold
magnetic float switches.
7. Mechanical Connection
The slide-tube of the float switch may not be bent or exposed to hard impacts,
since otherwise the reed contacts inside the tube can be damaged.
Adjustment-rings or anchor-clamps may not be readjusted, since otherwise the
switching function (N.O. contact, N.C. contact or changeover switch) is no more
guaranteed.
Ensure the correct use of cable gland and gasket on float switches with plug to
prevent the penetration of humidity.
While installation is carried out, please ensure that the float can move freely (due
allowance should be given to distances from side-walls!).
Mounting position of the slide-tube may not deviate more than ±30° from vertical
position.
If the float has to be removed, pay attention to correct orientation when replacing
the float.
8. Area of application
Magnetic level switch MS series are used exclusively for level control and
monitoring of liquid media.
The liquids should not contain suspended solids or tendency to crystallize.
Ensure that the construction materials of the float switch have chemical
resistance sufficient to prevent mechanical deformations that may affect it.
9. Maintenance
In liquids that can cause deposits, the float has to be cleaned at regular intervals.
In this case the measuring tube and float should be cleaned from such deposits.
Other maintenance jobs are not required.

MS series
page 7 DT0493
10. Technical Data
Contact NO/NC: 230 VAC/DC / 1 A / 60 VA ( MS05...MS10 )
Contact SPDT: 230 VAC/DC / 1 A / 60 VA ( MS05...MS10 )
Atex-version: Ui: 40V, Li: negligible, Ci: negligible
Protection type: IP65
Min. liquid density: See float design table
Max. pressure (at 20ºC): 3 bar ( MS05, MS07 )
30 bar ( MS10 )
100 bar ( MS06 )
Max. temp. with PVC cable: 55ºC ( models with PVC tube )
70ºC ( Models without PVC tube )
Max. temp. with. silicone cable: See max. temperature in float design table
Max. length of guide tube: 2 m ( PVC Ø12 mm )
4 m ( st. st. or brass Ø12 mm )
Hysteresis: 5 mm difference in level
Definition of switching points referred to density 1 Kg/dm3
Attention models without earth conductor must be used only with safety extra low
voltage ( i.e. contact protection relays ) or external earthing.

MS series
page 8 DT0493
11. Electrical Information
Performance data indicated on the device label are absolute maximum ratings,
which may not be exceeded even for brief periods of time. They refer to ohmic
load (resistive load). When switching inductances (e.g. coils from relays and
contactors), the contacts of the float switches should be protected employing
suitable means from high cut-off voltage surges.
Examples of protection circuitry
For capacitive, inductive and lamps load, we recommend our contact protection
relays or the following suppressor circuits.
Lamp load with series or parallel Protection with a RC suppressor
resistance to the reed switch. for a.c. current and inductive load.
Protection with a diode Protection with an inductance or
for d.c. current and inductive load. resistance for capacitive load.
The Magnetic Level Switches are connected according to the following connection
diagrams.
Attention! While making electrical connections of these devices,
please observe relevant safety measures, norms, regulations and EG-
guidelines, in particular, DIN VDE 0100, section 610. Float switches
made of PVC can be used up to max. 55 °C!

MS series
page 9 DT0493
Connection diagrams
Colour coding per DIN 47100
Terminal
connection
coding in
connection
head
Cable colour
coding
(DIN47100) for
standards in
silicone and PVC
1 WH White
2 BN Brown
3 GN Green
4 YE Yellow
5 GR Grey
6 PK Pink
7 BU Blue
8 RD Red
9 BK Black
* For special cables the codification is by numbers
Models MS05….MS10
1 switch point ( L1 )
2 switch points ( L1, L2 )
L1- S or C L1- W
L1- S or C
L2- S or C L1- W L2- W L1- S or C L2- W L1- W L2- S or C

MS series
page 10 DT0493
3 switch points ( L1, L2, L3 )
L1- S or C
L2- S or C
L3- S or C
L1- W
L2- W
L3- W
L1- S or C
L2- S or C
L3- W
L1- S or C
L2- W
L3- S or C
L1- W
L2- S or C
L3- S or C
L1- W
L1- W
L3- S or C
L1- W
L2- S or C
L3- W