Kobold VKG User manual

Operating Instruction
for
Viscosity Compensated
Flow Meter and Monitor
Model: VKG

VKG
Page 2 VKG K09/0322
1. Contents
1.Contents ........................................................................................................ 2
2.Note .............................................................................................................. 3
3.Instrument Inspection .................................................................................... 3
4.Regulated Use .............................................................................................. 3
5.Operating Principle ........................................................................................ 4
6.Mechanical Connection ................................................................................. 5
7.Electrical Connection .................................................................................... 6
8.Use in hazardous area .................................................................................. 7
8.1.Statement an apparatus not containing an own potential ignition
source .................................................................................................. 7
8.2.ATEX reed contact 41R57** ............................................................... 9
9.Commissioning............................................................................................ 15
10.Maintenance ............................................................................................... 16
11.Technical Information .................................................................................. 16
12.Ordering Codes ........................................................................................... 18
13.Recommended Spare Parts ........................................................................ 19
14.Dimensions ................................................................................................. 20
15.EU Declaration of Conformance (VKG) ....................................................... 22
16.UK Declaration of Conformity (VKG) ........................................................... 23
17.EU Declaration of Conformance (Reed contact 41R57**) ........................... 24
18.Statement of conformity reed contact 41R57** ........................................... 25
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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VKG K09/0322 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.
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.
Diagram 8, Pipe, Group 1 dangerous fluids
3. Instrument Inspection
These devices are checked before dispatch and sent away in perfect condition.
Should the damage to a device be visible, we recommend a thorough inspection
of the delivery packing. In case of damage, please inform your parcel service/
forwarding agent immediately, since they are responsible for damages during
transit.
Scope of delivery:
 Viscosity Compensated Flow Meter and Monitor model: VKG
4. Regulated Use
Model VKG instruments are used for the measurement and monitoring of viscous
liquid flows (max. 760 mm2/s). Only clean and homogeneous media may be
measured, which do not affect the materials used in the instrument casing.
Large measuring errors will occur when using higher viscosity media. Large dirt
particles may lead to blocking of the float and therefore to large measurement and
signal errors.

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Page 4 VKG K09/0322
Ferritic particles that deposit on the float body (with internal magnet) may also lead
to a similar effect.
The instruments are provided as follows:
Flow measurement
The actual flow may be read locally off the instrument. The top of the float indicates
directly the flow rate in litres per minute on the scale.
Limit Value Contacts (only for model VKG- 2.. and VKG-3..)
For the monitoring of the flow rate, the instruments may be fitted with one or two
adjustable limit value contacts.
Standard design: Normally open reed contacts (with increasing flow)
Special design: Changeover reed contacts
The contact is adjustable over the full measuring range.
Standard Material Combinations
Material: Brass Material: Stainless Steel
Outer casing
A
luminium, anodised
A
luminium, anodised
Spring St. Steel 301 St. Steel 301
Orifice St. Steel 301 / brass St. Steel 301
Magnet Ceramic oxide Ceramic oxide
Connections Brass St. Steel 304
Float Brass St. Steel 304
Measuring tube Borosilicate Borosilicate
O-rings NBR FPM
Tmax. 100 °C 100 °C
Pmax. 12 ba
r
12 ba
r
5. Operating Principle
A float with sharp edged orifice apertures is located within
a cylindrical glass measuring tube. When a flow occurs,
the medium lifts the float against a spring which exerts a
force downwards on the float. Each position of the float
corresponds to a particular flow throughput, which may be
read off the scale marked on the glass measuring tube.
Permanent magnets are mounted on the float which
activates reed switches positioned outside of the flow
throughput. The activation of the contacts is carried out by
means of magnetic field, i.e.: the contact is hermetically
separated from the flowing medium.

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VKG K09/0322 Page 5
6. Mechanical Connection
Before installation:
 The instrument may be mounted in any position. No modifications are neces-
sary. The flow takes place in the direction of the arrow (on the label).
 Remove all transport packing and ascertain that no packing material is left in
the instrument.
 Sealing of the connection threads should be carried out with Teflon tape or
similar.
 During installation of the instrument, it must be checked that no strong forces
will be applied to the connections. We recommend fixing the inlet and outlet pipes
mechanically at approximately 50 mm from each instrument connection.
 The instrument must not be installed within an induction field.
Attention! The threaded connection of the instrument must be
tightened with a suitable size of open ended spanner. Otherwise,
the housing may be stressed which could lead to breakage of
the instrument.
 If possible, check directly after mechanical installation that the connection
thread to pipe is fully sealed (see section commissioning)
Attention! Please note that when installed in open spaces freezing
of the medium can lead to breakage of the glass tube.
 Please ascertain whether the allowable
maximum operating pressure and operating
temperature of the instruments will not be
exceeded (see table: standard material
combinations).

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7. Electrical Connection
(Only for Models VKG-2.. and VKG-3..)
 Make sure that the supply wires are de-energized.
 Loosen the holding screw of the plug cap and remove the
cap from the plug.
 Connect the power cable to the plug cap in accordance
with the connection diagram below.
 If the contact has as yet not been adjusted, this should be
carried out at this stage (see section 9 commissioning)
 Connect the plug to the contact connections and secure it
with the holding screw (see section 9 commissioning).
Attention! Electrical values of the reed contacts may not be
exceeded even for short periods. For higher switching values we
recommend contact protection relays.
Following connection of the external equipment to the output and adjustment of the
required switch points, the external power supply to the equipment may be
switched on.
Examples for Contact Protection Measures
For capacitive and inductive loads (long cables and relays/protection) we
recommend protective switching.

VKG
VKG K09/0322 Page 7
8. Use in hazardous area
8.1. Statement an apparatus not containing an own potential
ignition source

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Page 8 VKG K09/0322

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VKG K09/0322 Page 9
8.2. ATEX reed contact 41R57**
ATEX N/O contact 41R57
II 3G Ex ic IIC T4 Gc
II 3 D Ex ic IIIC T125 °C Dc
-20 °C ≤Ta≤80 °C
max. 250 V
AC/DC
/1.5 A/100 W/100 VA
ATEX changeover contact 41R57U
II 3G Ex ic IIC T4 Gc
II 3 D Ex ic IIIC T125 °C Dc
-20 °C ≤Ta≤80 °C
max. 250 V
AC/DC
/1 A/30 W/60 VA
Ex-relevant excerpt of the operating instructions of the reed contact
41R57 **
1. Preambel
This excerpt of the operating instructions only represents the ex-relevant aspects.
It is copied into the original operating manual in the same or analogous form;
Textual changes are permitted, the ex-relevant statements remain.
To ensure the function and for your own safety, please read the enclosed operating
instructions carefully before you begin the installation. If you have any questions,
please contact the KOBOLD Messring GmbH, Hofheim. It applies with the original
operating instructions.
The following standard issues were considered in the evaluation of the product:
a) IEC 60079-0:2017 Ed. 7 / EN 60079-0:2018 Explosive atmospheres –
Part 0: Equipment - General requirements
b) IEC 60079-11:2011 Ed. 6 + Corr. 2012 / EN 60079-11:2012 Explosive
atmospheres - Part 11: Equipment protection by intrinsic safety "i"
2. General information on explosion protection
The reed switches work together with various KOBOLD products and serve there
for monitoring. It is available as N/O contact or changeover contact.
The electrical connection is made via a plug - only in intrinsically safe systems.
The reed switch is intended for commercial use and may only be used in
accordance with the specifications in the technical documentation of Kobold and
the information on the nameplate. It is only operated together with certified products
via an intrinsically safe circuit. They comply with the valid standards and
regulations.
The installation regulations (e.g. EN 60079-14) for systems in potentially explosive
atmospheres must be observed.
Further important details can be found in the corresponding EC-type examination
certificate.

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Permitted use
• The intrinsically safe reed switch can be used as follows:
• In Zone 2 (Gas-Ex, EPL Gc) in explosion groups IIA, IIB and IIC
• In Zone 22 (Dust-Ex, EPL Dc) in explosion groups IIIA, IIIB and IIIC
• The requirements for simple electrical equipment for use in intrinsically safe
circuits in zones 1/21 are fulfilled.
• The qualification regarding the surface temperature is T4. For all gases, vapors,
mists with an ignition temperature> 135 ° C the equipment is not an ignition
source.
• In the dust Ex area, 125 ° C is the reference temperature for further
consideration regarding the safety distance from the smoldering temperature.
• The ambient temperature range is -20 ° C ≤ Ta ≤ 80 ° C.
2.1. Electrical characteristics for Ex i
Electrical data:
• Rated voltage up to 45 volt AC / DC
• Rated current up to 2 A
• UiIC ≤ 30 V AC / DC, IiIIC ≤ 250 mA
• UiIIB ≤ 45 V AC / DC, IiIB ≤ 2 A
• UiIIIC ≤ 45 V AC / DC, IiIIIC ≤ 250 mA
• Li = negligible, Ci = negligible
• Heating on the outer housing <15 K
2.2 Type code
The equipment is identified by the following type code:
Type Description Item-No. Remarks
41R57 A B T
y
pe codin
g
41R57 Contact device
A
N/O contact
(
2 wires
)
, Plu
g
with black cap
Change-over contact (3 wires), Plug with grey
cap
B 70
–
75 with markin
g
(
not ex-relevant
)
202.289 N/O
45 – 50 with marking 202.285 N/O
50
–
55 with markin
g
202.286 N/O
60
–
65 with markin
g
202.287 N/O
70 – 75 with marking 202.288 Change-over
60
–
65 chan
g
e-over contact 202.290 Chan
g
e-over
2.3 Temperature class
The reed switch is suitable for temperature class T4 / T125 ° C.