Kobold NBK-16 User manual

Operating Instructions
for
Plastic
Bypass Level Indicator
Model: NBK -16
-17

NBK-16/ -17
page 2 NBK-16/ -17 K05/0722
1. Contents
1. Contents........................................................................................................2
2. Note ..............................................................................................................3
3. Instrument Inspection....................................................................................3
4. Regulation Use .............................................................................................3
5. Operating Principle........................................................................................4
6. Mechanical Connection.................................................................................5
6.1 Mounting..............................................................................................5
7. Electrical Connection ....................................................................................6
7.1 General................................................................................................6
7.2 Magnetic Switches...............................................................................7
7.3 Level Transmitter (Type ...W) ..............................................................8
7.4 Two-wire Head transducer (Type ...M).................................................8
8. Configuration / Adjustments..........................................................................9
8.1 Setting the Magnetic Switches.............................................................9
8.2 Adjustment of the level sensor (Type ...W)..........................................9
8.3 Setting Limit Values (Model – RPVC)..................................................9
8.4 Two-wire Head Transducer (Type ...M) ...............................................9
9. Commissioning............................................................................................10
9.1Function Test.....................................................................................10
10. Assembly ....................................................................................................11
11. Maintenance ...............................................................................................12
12. Technical Information..................................................................................13
13. Order Codes ...............................................................................................15
14. Dimensions .................................................................................................16
15. Disposal......................................................................................................18
16. EU Declaration of Conformance .................................................................19
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 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, category I
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:
•Bypass Level Indicator model: NBK-16/ -17
4. Regulation Use
Any use of the Bypass Level Indicator, model: NBK-16 or 17, 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.

NBK-16/ -17
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5. Operating Principle
Kobold plastic level indicators are used for continuous measurement, display and
monitoring of liquid levels. The bypass tube is attached to the sidewall of the
vessel. According to the hydrostatic pressure principle the level in the bypass
tube equals the level in the vessel. A float with embedded circular magnets in the
bypass tube follows the liquid level and transfers it in a non-contacting manner to
a display on the tube. Additionally, the NBK can be fitted with level switches or
transmitters for remote indication and monitoring of liquid levels. The following
indication and monitoring devices are available:
Magnetic roller indicator
As the float passes by, the red/white rollers are rotated in succession by 180°
around their own axes. The rollers change from white to red as the level rises and
from red to white as the level falls. The level is continuously displayed as a red
column. As the indicator is magnetically activated and requires no power to
operate, it will continue to provide local indication even in the event of power
failure.
Transmitter
A resistive transmitter can be mounted outside the bypass tube to remotely
transmit the level. A continuous standard signal of 4 to 20 mA is generated by
means of an integral transmitter.
Limit contacts
Adjustable reed contacts for alarms or for level control can be secured to the
bypass tube.

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6. Mechanical Connection
6.1 Mounting
•The maximum rated pressure and temperature values specified on the type
plate may not be exceeded.
•Prior to system start up, the bypass level indicator must be included in the
vessel pressure test.
•The float is designed for the medium density specified on the type plate.
The measurement deviates if it is used in liquids with a different specific
gravity.
•The medium to be monitored may not be heavily contaminated or contain large
particles. The media should not have a tendency to crystallize.
•At medium temperatures below - 20°C, the bypass level indicators must be
insulated and a plexiglas attachment must be fitted to the magnetic roller
display.
•The magnetic roller display and attached magnetic switches must be aligned
with the supplied float before installation.
•The bypass level indicator may not be placed in the immediate vicinity
(<1 meter) of strong electromagnetic fields.

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7. Electrical Connection
7.1 General
Caution! Make sure that the voltage and current values of your
system are within the limits of the bypass level indicator
electrical specifications.
Note! In order to guarantee safe, reliable operation, bypass level
indicators which are operated at medium temperature below
-20 °C must be insulated and a plexiglas attachment must be
fitted to the magnetic roller display. Insulation must be as
specified in the „General Insulation List“ (AGI List).
Warning! If floats with pressure equalization are fitted, care
must be taken that the operating pressure at the bypass level
indicator is raised slowly. Sharp variations and sudden changes
in pressure can result in destruction of the float.
7.1.1 Installation of the Float
1. Remove the fitting at the bottom of the bypass tube and insert the float into the
pipe from the bottom.
(Pay attention to the marking "top" (above). Ensure that the end marked “top” is
inserted first.)
2. Replace the base fitting, insert the gasket and fix with screws.
Note! All cabling and electrical connections must be carried out
in accordance with the regulations applicable in the country
where the equipment is installed and by qualified personnel.

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7.2 Magnetic Switches
The connection should be made with cable at least 3 x 0.75mm² according to the
wiring diagram. The contact should be connected according to the desired switch
logic.
Connecting diagram magnetic switch
Operation via a contact protection relay is recommended to prolong the life of the
contacts.
Warning! Use of magnetic switches with inductive or capacitive
load may lead to the destruction of the reed switch. This may
cause a malfunction to the control circuitry and harm to persons
or goods. With inductive load, magnetic switches have to be
connected to a RC Network (AC loads) or a suppression diode.
With a capacitive load, connecting cables longer than 50m or connection to a
PLC with capacitive input circuit, a 22. resistor is required to be connected in
series to limit current spikes.

NBK-16/ -17
page 8 NBK-16/ -17 K05/0722
Warning! Overloading the magnetic switches may lead to the
destruction of the reed switch, which may cause a malfunction to
the control circuitry and harm to persons or goods. The maximum
switch capacity values given on the tag label must not be exceeded.
7.3 Level Transmitter (Type ...W)
The level transmitter must be connected according to the wiring diagram printed
on the transmitter and wired to the electronic evaluation unit in series. A shielded
cable must be used and the shield should be grounded at one end for long lines
or if the cables are laid together with power cables.
The cable gland must then be sealed and the lid of the terminal box be closed
tightly.
7.4 Two-wire Head transducer (Type ...M)
The principal connection of Two-wire 4-20 mA transmitter is shown in the wiring
diagram below. The wiring diagram of the actual used transmitter should always
be observed.

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8. Configuration / Adjustments
8.1 Setting the Magnetic Switches
The magnetic switches can be set to the desired switch point by sliding them up
or down the bypass tube. The set screws must be loosened to do this. The switch
point of the switch is in the center of the contact block unless specified otherwise.
The set screws must be re-tightened after setting the switch point.
Note! Magnetic switches are fitted as standard on the right-hand
side of the magnetic roller display. If switches are transferred to
the other side, the contact function is reversed.
8.2 Adjustment of the level sensor (Type ...W)
The level sensors are factory pre-calibrated. Further adjustments are not
necessary. Please follow the instructions for the control unit used in conjunction
with the sensor.
Please do not unlock and more the transducer as this may change calibration.
8.3 Setting Limit Values (Model – RPVC)
See the operating instructions of the limit value transmitters used for setting limit
values.
8.4 Two-wire Head Transducer (Type ...M)
Level sensors and transmitters are matched at the factory. No adjustment is
necessary.

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9. Commissioning
9.1 Function Test
9.1.1 Magnet Roller Indicator
1. Move the removed float slowly from bottom to top on the face of the indicator.
The indicator must change evenly from white to red.
2. Move the float slowly from top to bottom. The indicator changes from red to
white.
This test is not possible for indicators with Plexiglas attachments.
9.1.2 Magnetic Switch
1. Activate the magnetic switch by moving the float from bottom to top. The
contact should switch.
2. Move the float from top to bottom. The contact drops back to its rest position.
9.1.3 Level Transmitter (Type ...W)
1. Disconnect the cable.
2. Connect ohmmeter to two wires.
3. Move the float by hand from the Min. to Max. position.
4. The displayed resistance changes depending on the connected wire colours:
Warning! During functional testing, certain actions in the control
circuit may be triggered unintentionally resulting in possible
harm to persons or goods. Control circuits have to be switched
off or components have to be disconnected for testing.

NBK-16/ -17
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10.Assembly
Alignment of the magnetic roller display
Before installation, align the magnetic roller display and any installed magnetic
switches to ensure that they are all set to the rest position prior to starting the
system. To do this, slowly move the supplied float from bottom to top along the
outside of the magnetic roller display and then back down again. Installed
magnetic switches must be aligned on the basis of the same principle. In the case
of bypass level indicators with insulation and magnetic roller display with
Plexiglas attachments, the float must be moved up and down inside the tube. For
magnetic roller displays with flushing connections, these connections must have
an air-tight seal.
Mounting the Bypass Level Indicator
Mount the bypass level indicator on the vessel to be monitored with the
appropriate process connections. Gaskets, screws, washers and nuts suitable for
the process connection must be used for assembly. Choose a gasket with a
suitable corrosion resistance. Isolation valves should be mounted between the
vessel and the bypass tube if possible.

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11.Maintenance
Bypass level indicators, magnetic switches and level transmitters operate free of
maintenance and wear if used properly. The float should be checked visually for
corrosion damage and leakage during tank inspection. The bypass chamber must
be completely emptied before removing the float. Shut- off devices must be
closed.
Warning! Pressurised bypass chamber, possibly containing hot,
toxic, or caustic liquid presents a potential hazard due to
splashing liquid. Burns to hands, legs and face, as well as
chemical burns or poisonings are possible. Chamber pressure
has to be released before opening. Please use protective wear
(gloves, safety mask, gas mask and breathing equipment).
The float can be removed after dismantling the bottom fitting. The float should be
reinstalled as described in the Assembly Section after being checked visually.

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12.Technical Information
Measuring length: 200 mm – 4000 mm
Bypass tube: ∅63 x 3 mm
Material: PP or PVDF
Process connection
(loose flange): DIN flange according to Din EN 1092-1 form B1
DN 20…DN 50, PN 10
ANSI flange B16.5 ¾“-2“, 150 lbs, RF
Operating pressure: max. 4 bar
Operating temperature: PP: max. 60 °C
PVDF: max. 80 °C
Min. density: 590 kg/m3(NBK-16)
790 kg/m3(NBK-17)
Seal: O-ring, EPDM (FPM, PTFE, FEP on request)
Bypass pipe top: pipe cap (dished boiler end DIN 2617)
Bypass pipe bottom: threaded connection with drain screw, threaded
connection with loose drain flange (without
counter flange)
Overall length: depending on measuring length,
see dimension drawing
Installation position: vertical
Roller indication:
Housing: aluminium anodized
Indication rollers: PBT red/white
Front cover: Makrolon PC
Max. ambient temperature: 200 °C
Limit Contacts (NBK-RPVC):
Housing: Aluminium anodized
Contact operation: bistable changeover contact (reed contact)
Max. switch capacity: 230 VAC, 60 VA, 1 A
230 VDC, 30 W, 0,5 A
Cable: 1 m PVC (NBK-RPVC)
3 x 0.75 mm2
Ambient temperature: max. 90 °C
Protection: IP 65
Reed contact resistor chain model...W:
Housing: Aluminium painted
Measuring principle: Reed contact chain
Sensor tube: stainless steel 1.4571
Total resistance: 3.2...50 kΩ(depending on length)
Measuring-circuit voltage: max. 24 VDC
Measuring current: max. 0,1 A
Resolution: 10 mm
Protection: IP 65
Cable entry: M20 x 1.5

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Reed contact resistor chain with 2-wire transmitter model...M:
Housing: Alumium painted
Output: 4...20 mA
Supply Voltage: 11...30 VDC
Max. load: 1000 Ωat UB= 30 VDC
700 Ωat UB= 24 VDC
50 Ωat UB=12 VDC
Ambient temperature: -20... +60 °C
Resolution: 10 mm
Protection: IP 65
Cable entry: M20 x 1.5

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13.Order Codes
Model1) Material Connection2) Nominal size Roller indication Transmitter Media density/Float 3)
(kg/m3) Bypass pipe (bottom)
NBK-16... PP
F= DIN flange
A= ANSI flange
20=DN 20, ¾“
25=DN 25, 1“
32=DN 32, 1 ¼“
40=DN 40, 1 ½“
50=DN 50, 2“
00 = without
RP = PBT rollers
0= without
W= Reed contact
chain
M= Reed contact
chain with transmitter
4...20 mA
2-wire
1= Nom. Density 1320,
Min. Density 1200
2= Nom. Density 970,
Min. Density 910
3= Nom. Density 790,
Min. Density 750
4= Nom. Density 680,
Min. Density 660
5= Nom. Density 610,
Min. Density 590
1= Threaded
connection with
drain screw G ½
2= Threaded
connection with
drain screw ½ “
NPT
3= Threaded
connection with
drain flange DIN
DN 15/PN16
A= Threaded
connection with
drain flange ANSI
½ “ 150 lbs
NBK-17... PVDF
A= Nom. Density 1480,
Min. density 1340
B= Nom. Density 1140,
Min. density 1070
C= Nom. Density 980,
Min. density 930
D= Nom. Density 890,
Min. density 850
E= Nom. Density 810,
Min. density 790
NBK-RPVC Standard limit contact (bistable changeover contact), 1 m PVC cable
1) Please specify in writing: measuring length ‘L’, medium density, operating pressure (max. 4 bar) and operating temperature
2) Flange connection pressure rating standard is PN10. (PN16, PN25, PN40 on request)
3) Tared/balanced float according to media density is optional available at extra charge. Float tare must be specified. Standard is without tare.
Any deviation between media density and floats nominal causes an additional error in measurement.
Without float tare the minimum float density is stated on the instrument label.

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14.Dimensions
Bypass Float
Model
Diameter D
[mm]
Length L
[mm]
Material
1
50
150
PP
2
50
200
PP
3
50
250
PP
4
50
300
PP
5
50
350
PP
A
50
150
PVDF
B
50
200
PVDF
C
50
250
PVDF
D
50
300
PVDF
E
50
350
PVDF

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NBK-16/ -17 K05/0722 page 17
Reed contact chain
Clearance dimension A [mm]
Model
Material
Medium density
590 kg/m3660 kg/m3750 kg/m3910 kg/m31200 kg/m3
NBK-16
PP
320
270
220
170
170
Model
Material
Medium density
790 kg/m3850 kg/m3930 kg/m31070 kg/m31340 kg/m3
NBK-17
PVDF
320
270
220
170
170
NBK-RPVC

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15.Disposal
Note!
•Avoid environmental damage caused by media-contaminated parts
•Dispose of the device and packaging in an environmentally friendly
manner
•Comply with applicable national and international disposal regulations and
environmental regulations.
Batteries
Batteries containing pollutants are marked with a sign consisting of a crossed-out
garbage can and the chemical symbol (Cd, Hg, Li or Pb) of the heavy metal that
is decisive for the classification as containing pollutants:
Cd1Hg2Pb3Li4
1. „Cd" stands for cadmium
2. „Hg" stands for mercury
3. „Pb" stands for lead
4. „Li" stands for lithium
Electrical and electronic equipment

NBK-16/ -17
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16.EU Declaration of Conformance
We, KOBOLD Messring GmbH, Hofheim-Ts, Germany, declare under our sole
responsibility that the product:
Bypass Level Indicator model: NBK -16/ -17
to which this declaration relates is in conformity with the standards noted below:
EN 13445 Unfired pressure vessels
Also, the following EC guidelines are fulfilled:
2014/68/EU PED, category I, module A
2011/65/EU RoHS
The standard limit contact model: NBK-RPVC
is in conformity with the standards noted below:
EN 61010-1:2010 Safety requirements for electrical equipment for
measurement, control and laboratory use - Part 1: General requirements
EN 50581:2012 Technical documentation for the assessment of electrical
and electronic products with respect to the restriction of hazardous substances
Also, the following EC guidelines are fulfilled:
2014/35/EU Low Voltage Directive, U ≥50 VAC/75 VDC
2011/65/EU RoHS
Hofheim, 21. Sept. 2017
H. Peters M. Wenzel
General Manager Proxy Holder