Kobold NBK-04 User manual

Operating Instructions
for
Over-Head Level Indicator
Model: NBK-04

NBK-04
page 2 NBK-04 K01/0922
1. Contents
1.Contents ........................................................................................................ 2
2.Note .............................................................................................................. 3
3.Instrument Inspection .................................................................................... 4
4.Regulation Use ............................................................................................. 5
5.Electrical connection ..................................................................................... 6
6.Operating Principle ........................................................................................ 6
7.Mechanical Connection ................................................................................. 7
8.Trouble Shooting ........................................................................................... 9
9.Maintenance ................................................................................................. 9
10.Technical Information .................................................................................. 10
11.Diagram Density / Length of Measuring Tube ............................................. 11
11.1.NBK-04...8, diagram 8 ....................................................................... 11
11.2.NBK-04...6, diagram 6 ....................................................................... 12
11.3.NBK-04...4, diagram 4 ....................................................................... 13
12.Order Codes ............................................................................................... 14
13.Dimensions ................................................................................................. 15
14.Disposal ...................................................................................................... 18
15.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

NBK-04
NBK-04 K01/0922 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
Model Over-
length*
p max
[bar]
Medium
no dangerous
(
dia
g
r. 2
)
Medium
dangerous
(
dia
g
r. 1
)
NBK-04  645 16 Art.4, Para.3 Art.4, Para.3
NBK-04  1270 16 Art.4, Para.3 I
NBK-04  4230 16 I II
* see dimensions in section 13

NBK-04
page 4 NBK-04 K01/0922
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:
 Over-Head Level Indicator model: NBK-04

NBK-04
NBK-04 K01/0922 page 5
4. Regulation Use
Any use of the device, 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.
Kobold over-head level indicators are used for continuous measurement, display
and monitoring of liquid levels. The float inside the tank is attached by means of a
connecting rod to the magnet carrier in the over-head tube. The magnet fitted in
the magnet carrier operates, in a non-contacting manner, the display and
monitoring devices fitted outside tube.
The over-head measuring tube system
The over-head tube is attached with the vessel with a connection flange. The
installation position is always vertical. The NBK should only be used for liquids
with the medium density specified on the unit label. Otherwise, the indication may
be inaccurate and the float may submerge.
System pressure and temperature should not exceed the specified maximum
values, as this can lead to the destruction and malfunction of the over-head
system. Ensure that the liquids contacting the level indicator internals are
chemically compatible with the materials used in the construction of this unit.
Proper operation is also impaired by:
 High degree of soiling
 Large particulate
 Crystallisation
 Ferrite particles

NBK-04
page 6 NBK-04 K01/0922
5. Electrical connection
Optional electrical add-on parts (transmitter and limit contacts)
There is a separate operating manual for the assembly and commissioning of the
optional electrical add-on parts “Operating manual for NBK transmitters and
limit contacts”.
These operating instructions document the following electrical add-on parts:
Transmitter:
Reed contact resistor chain model W
Reed contact resistor chain with transmitter model M
Magnetostrictive sensor with transmitter model T
Reed contact resistor chain with transmitter model AE/AC
Reed contact resistor chain with transmitter HART model HE/HC
Reed contact resistor chain with transmitter FF model F
Limit Contacts:
Reed switch limit contact model NBK-R
Limit contact high temperature model NBK-RT200/RT400
Reed switch limit contact model NBK-RV200NO/RV200NC
Reed switch limit contact NAMUR model NBK-RV200NO/RV200NC
6. Operating Principle
A float in a dip pipe is connected with the magnet actuator inside the over-head
tube via a connecting rod.
The built-in magnet inside the magnet carrier triggers the mounted display and
other options (e.g. switches/transmitters) attached to the tube externally, in a non-
contacting manner.
Magnet roller indication
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 in a tank or a mixer is continuously
displayed as a red column, even when the power fails.

NBK-04
NBK-04 K01/0922 page 7
7. Mechanical Connection
Remove the cotter pin from bottom end of the dip
pipe, next, remove the transport lock of the float.
Fix the float with the magnet system towards top
and make sure, there are no remains of packing
material or other impurities inside the tube.
Set the cotter pin back and widen it. Secure the
measurement system by means of a connecting
flange on your container/drum/vessel.
Should the NBK be subjected to constant shock or
strong vibrations, it is recommended that the
instrument will be secured with damping-rubber
tube clips. In any case, the over-head tube should
never be welded onto the tank.
Final
Measurement
Measuring length
Measuring length
Initial
Measurement
Initial
Measurement
Final
Measurement
Connection flange
Roller indication

NBK-04
page 8 NBK-04 K01/0922
Needed size of the assembly tube of the vessel side
Over-Head Level Indicator
vessel side
Flange Diameter  NBK-04-tube
Min. diameter  of the
submerged tube on the
vessel side
PN 16 DN 65/ 2 ½“ ANSI  76.1mm  88.9 x 2 mm
PN 16 DN 50/ 2“ ANSI  60.3mm  76.1 x 2 mm
NBK-connection flange
vessel connecting flange
Min. 

NBK-04
NBK-04 K01/0922 page 9
8. Trouble Shooting
Error: The tank is full but there is no indication
 Check that the float is present in the system.
 If the float is present, check whether it is being blocked by foreign objects or
dirt deposits.
 Check the op. SG of the float and the medium.
Error: The tank is full but the indication is too low.
 Check that the density of the liquid is in accordance with the density prescribed
on the unit-label.
 Check that the float has been correctly installed.
 Check if dirt deposits in the over-head tube are blocking the float.
9. Maintenance
If encrustations or crystallizations build up in the immersion tube, the measuring
system must be dismantled and mechanically cleaned.
The viewing window of the roll display is made of high-quality Plexiglas and can
be cleaned with a suitable cleaning agent if necessary.
The indicator does not otherwise require any maintenance.

NBK-04
page 10 NBK-04 K01/0922
10. Technical Information
Over-head tube: Ø 60.3 mm x 2 mm
Tank tube: Ø 60.3 mm x 2 mm or Ø 76.1mm x 2mm
Material: st. steel 1.4571
Initial measurement: 270 mm from end or tank tube
Float: titanium
Connecting rod: rod or tube from titanium or st. steel 1.4571
(depending on medium density and measuring
length)
Flange nominal size: DIN EN 1092-1 DN 50, 65, 80, 100, PN 16
ASME B16.5 2”, 2 ½”, 3”, 4”, Class 150
Max. operating pressure PN 16
Operating temperature: -50 °C...+120 °C (POM rollers)
-104…+120 °C (ball display)
Viscosity: max. 200 mm2/s
Measuring length: min. 600 mm
max. 4000 mm
Total length: see dimension drawing
Min. density: 0.43 kg/dm3
ATEX approval: see separate description
Housing: aluminium pressure-cast, terminal connection
Cable entry: M16x1.5, brass nickel-platted
Protection: IP 65