Kobold RFS User manual

Operating Instructions
For
Magnetic level switch
RFS

RFS
Page 2 DT0649
1. Content
1.Content ......................................................................................................... 2
2.Note .............................................................................................................. 3
3.Instrument Inspection .................................................................................... 3
4.Description .................................................................................................... 3
5.Operation ...................................................................................................... 4
6.Use in Hazardous Areas ............................................................................... 4
7.Mechanical Connection ................................................................................. 5
8.Electrical Connection .................................................................................... 6
9.Models .......................................................................................................... 8
10.Technical data ............................................................................................... 9
11.Safety Instructions ( ATEX ) ........................................................................ 11
12.Installation in ATEX areas ........................................................................... 12
13.Electrical connection in ATEX area ............................................................. 13
14.Label description (ATEX) ............................................................................ 13
15.EU Declaration of conformity (ATEX) .......................................................... 14
16.EU Declaration of conformity ...................................................................... 15
17.UK Declaration of conformity ...................................................................... 16
18.ATEX Certified ............................................................................................ 17
19.Notes ........................................................................................................... 17
Manufactured by:
Kobold Mesura S.L.U
Av. Conflent Nº68 Nave 15
08915 Badalona
Tel.: [phone]
Fax: [phone]
E-Mail: [email protected]
Internet: www.kobold.com
Edition: May 2022

RFS
DT0649 Page 3
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 switch RFS
 Operating instructions
4. Description
Model RFS devices are used for monitoring liquid levels. The device should only be
used with liquids that are compatible with the unit´s materials of construction.
The standard version can be mounted in a wide range of installations while the ATEX
version is to be mounted in classified installations category 1 requiring certification
1G Ex ia IIC T6, 1D Ex ia IIIC T85ºC Da.

RFS
Page 4 DT0649
5. Operation
Working principle is based on the magnetic field of a magnet that activates the reed
contact.
RFS have the magnet located inside the float, the float is balancing following the
liquid level. When magnetic field of the magnet in the float reaches the reed contact
or the micro switch located in the fixed part of the instrument, it switches and
indicates the level of the tank.
The switching function (N/O contact N/C contact) is determined by the mounting
position. The switching function is reserved by simply rotating the switch through
180º.
6. Use in Hazardous Areas
With the approval the Level Switch, model RFS, can be used within hazardous areas.
Thereby the aluminium housing is applicable outside the process in zone of category
1GD.
The approvals are as follows:
II 1 GD Ex ia IIC T6 Ga
Ex ia IIIC T85ºC Da
-20≤Ta≤+60ºC
An additional intrinsically safe relay is required in environment with gas explosion
hazards (KFA...and respectively KFD).
For a correct and professional potential equalization, the ground terminal on the
housing of the RFS must be connected in applications in hazardous areas.

RFS
DT0649 Page 5
7. Mechanical Connection
The Level Switch should be mounted so that the float can move freely over its entire
path without hitting the wall, floor or roof of the container. Avoid fitting the switch where
agitators or inlet valves could expose it to excessive turbulence.
Make sure that the medium does not contain solids or ferrite particles, as they could
collect on the float magnet and interfere with the switching operation. If the liquid does
contain sediment or suspended matter, you must be sure they do not come into contact
with the float system.
Mount the switch in a way that is easily accesible for installation and maintenace.
 Do not hit the instrument.
 Do not install the instrument close to magnetic fields to avoid malfunctioning.
 Avoid mechanical vibrations.
 Be sure that the media (liquid) has no solid particles.
 Be sure that the media is chemically compatible with instrument materials.
 Make sure that the allowed max. operational pressure and service temperature for
the device is not exceeded.
 The installation position must be horizontal.
 If possible, examine all the connection joints for proper sealing, just after
mechanical intalation.
 The engraved arrow on the hexagon must point up or down depending on the
desired contact function. In any case the marked hexagon surface must always be
mounted vertically.
Mounting position
Depending on the mounting position of the device, the contact function (N/O or N/C
contact)of the level switch will be defined.

RFS
Page 6 DT0649
8. Electrical Connection
Caution! Make sure that voltage of your system
correspond with the voltage values of the level switch
 The switching power of Reed contacts of these magnetic levels is very low,
so they can only be connected to resistive high impedance loads, like PLCs.
 When load is relay, electro valve or other element that requires some power
it is absolutely necessary to protect the Reed contacts as follows depending
on load and voltage types.
 For the RFS version for ATEX applications, the connection of the potential
terminal is mandatory.
 An additional intrisically safe relay is required in environment with gast or dust
explosion hazards (KFA...and respectively KFD).

RFS
DT0649 Page 7
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 ex-
ample, be caused by self-induced e.m.f.`s when switching solenoid valves.
 Float switches are electrically isolated from the high voltage power supply sys-
tem.
 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 V
DC
 Mod. KFA6-SR2-Ex1.W 1 channel, 1 relay output, supply 230 V
AC
 Mod. KFD2-SR2-Ex2.W 2 channel, 2 relay output, supply 24 V
DC
 Mod. KFA6-SR2-Ex2.W 2 channel, 2 relay output, supply 230 V
AC
Pin assigment for RFS Level Switches
RFS-12N4_01200
RFS-12N4_11200 RFS-12N4_00000
RFS-12N4_001__

RFS
Page 8 DT0649
9. Models
RFS-12N4__1200 RFS-12G4__1200
RFS-12N4_00000 RFS-12G4_00000
RFS-12N4_00100 / RFS-12N4_001EX RFS-12G4_00100 / RFS-12G4_001EX

RFS
DT0649 Page 9
10. Technical data
Note: Kobold Mesura makes every attempt to ensure the accuracy of these
specifications, however, are subject to change without notice.
SERIE RFS
RFS-12N4__1200 | RFS-12G4__1200
Mounting Style: External
Process connection: G½ or ½" NPT
Stem: 1.4301 or 1.4404
Float: Ø17x47 - 1.4404
Medium max. Temp.: -40ºC...+120ºC
Max.pressure: 10 bar
Min. liquid density: >0.8g/cm³
Switching power max: 50W
Switching voltage max: 300Vac / 350Vdc
150Vac / 200Vdc (model with pt100)
Switching current max: DC 0.7 / AC 0.5A
Electrical connection: M12 4 poles
IP degree : IP65
RFS-12N4_00000 | RFS-12G4_00000
Mounting Style: External
Process connection: G½ or ½" NPT
Stem: 1.4301 or 1.4404
Float: Ø17x47 - 1.4404
Medium max. Temp.: -40ºC...+120ºC
Max.pressure: 10 bar
Min. liquid density: >0.8g/cm³
Switching power max: 50W
Switching voltage max: 300Vac / 350Vdc
Switching current max: DC 0.7 / AC 0.5A
Electrical connection: Connector DIN43650 (EN175301-803)
IP degree: IP65

RFS
Page 10 DT0649
RFS-12______0100
Mounting Style: External
Process connection: G½ or ½" NPT
Stem: 1.4301 or 1.4404
Float: Ø17x47 - 1.4404
Medium max. Temp.: -40ºC...+120ºC
Max.pressure: 10 bar
Min. liquid density: >0.8g/cm³
Switching power max: 50W
Switching voltage max: 300Vac / 350Vdc
Switching current max: DC 0.7 / AC 0.5A
Electrical connection: Aluminum housing
IP degree: IP65
RFS-12______01EX
Mounting Style: External
Process connection: G½ or ½" NPT
Stem: 1.4301 or 1.4404
Float: Ø17x47 - 1.4404
Medium max. Temp.: -40ºC...+120ºC
Max.pressure: 10 bar
Min. liquid density: >0.8g/cm³
Switching power max: 50W
Switching voltage max: Ui: 40V, Li: negligible, Ci: negligible
Switching current max: DC 0.7 / AC 0.5A
Electrical connection: Aluminium box
IP degree: IP65
ATEX Marking: II 1 GD Ex ia IIC T6 Ga
Ex ia IIIC T85ºC Da
-20≤Ta≤+60ºC