wbs 3000 - · pdf filesignal output is proportional to interface level so, ... figure 3. wbs...

Labkotec Oy Myllyhaantie 6 FI-33960 PIRKKALA FINLAND Tel: +358 29 006 260 Fax: +358 29 006 1260 12.3.2013 Internet: www.labkotec.com D22255Ae

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Copyright © 2013 Labkotec Oy We reserve the right for changes without notice

WBS 3000

Water Bottom Sensor for fuel oil and chemical storage tanks

Installation and Operating Instructions

WBS 3000 Water bottom sensor Installation and Operating Instructions

Copyright © 2013 Labkotec Oy

TABLE OF CONTENTS

1 GENERAL ................................

2 APPLICATIONS

3 TECHNICAL DATA

4 INSTALLATION

4.1 Suspended version

4.2 Flange mounted version

5 ELECTRICAL CONNECTIO

5.1 WBS 3000 Power supply requirements

6 APPROVALS

7 WARRANTY

8 TROUBLE-SHOOTING

SYMBOLS

Warning / Attention

Pay special attention to

Device is protected by double or reinforced insulation

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TABLE OF CONTENTS

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APPLICATIONS ................................................................................................

TECHNICAL DATA ..............................................................................................

INSTALLATION ................................................................................................

Suspended version ................................................................

Flange mounted version ................................................................

ELECTRICAL CONNECTIONS ................................................................

WBS 3000 Power supply requirements ................................

APPROVALS ................................................................................................

................................................................................................

SHOOTING ................................................................

Warning / Attention

Pay special attention to installations at explosive atmospheres

Device is protected by double or reinforced insulation

D22255Ae

We reserve the right for changes without notice

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installations at explosive atmospheres

WBS 3000 Water bottom sensor D22255Ae Installation and Operating Instructions

Copyright © 2013 Labkotec Oy 3/12 We reserve the right for changes without notice

1 GENERAL

The WBS 3000 is a special level sensor for continuous measuring of hydrocarbon product / water or other chemical / water interface in storage tanks. The capacitive WBS 3000 is ideal for gauging liquids with different densities and dielectric properties.

WBS 3000 is an apparatus of equipment-group II, category 1 G. It can be installed in zone 0/1/2 hazardous area.

Typical applications are large fuel oil storage tanks in oil terminals and refineries or underground rock-cavern storage tanks.

By utilizing WBS 3000 the storage tanks can be dewatered without time- and money-consuming emptying.

The sensor operates on a standard two-wire signal of 4-20 mA. The signal output is proportional to interface level so, that when the active length of the sensor is completely immersed in the product, the signal is 4 mA and when the active length is completely immersed in the water, the signal is 20 mA. Thanks to cast-in 4-20 mA transducer, the WBS 3000 is compatible with most of the PLC's or standard display units.

Since the WBS 3000 is a heavy-duty compact instrument containing no moving parts, it is very long-lasting and maintenance-free. Due to pre-calibration in the factory it doesn’t require calibrating.

The standard length for the sensing element (active length) is 350...3500 mm. Longer sensors may be manufactured by request.

There are two main principals for WBS 3000 installation: the sensor suspended between the vessel top and the vessel bottom or the sensor is flange (wall-) mounted in an angle.

When ordering the WBS 3000, it is essential to conf irm following issues:

- measured product (dielectric constant)?

- what is required active length?

- suspended or flange mounted version?

- if flange mounted, what is the existing flange an d desired installation angle?

- required cable length (standard is 10 m)?



2 APPLICATIONS

The WBS 3000 is a dedicated oil or chemical / water interface level sensor. It indicates continuously one interface level. The liquids must have different densities and dielectric properties.

Example:

The dielectric constant of diesel oil is approx. 2,2 and density is approx. 0,85 kg/dm3.

The dielectric constant of water is approx. 84 and density is 1,0 kg/dm3.

The differences between above values are big enough to ensure successful interface measurement.

We strongly recommend to avoid measuring liquids, which have high viscosity, are sticky or whose dielectric constant changes during measurement. We do not recommend applying the WBS 3000 in crude oil vessels.

The most typical application is water bottom measurement in a large fuel oil storage vessel:

Figure 1. Automatic remote control of dewatering of a large fuel oil vessel. WBS 3000 in suspended installation.



3 TECHNICAL DATA

WBS 3000 Water bottom sensor

Supply voltage 18…30 V DC (2-wire) Ex-approved power supply / barrier

Output 2-wire 4…20 mA proportional to interface level on active length

Accuracy ±0,3% (full scale) with jet fuel in constant tempaerature

Repeatability ±0.1%

Cable FEP-coated, shielded 2x0.75 mm2, twisted pair, standard length 10 m

Operating temperature -40 ºC…+90 ºC

Max. hydrostatic pressure 8 bar

Active length - suspended - flange

350...3500 mm according to order 350...10000 mm according to order NOTE! Inactive length in the downmost end is 85 mm.

Total length - suspended

- flange

Active length + approx. 585 mm (with suspension bracket). Active length + approx. 585 mm, depending on installation flange

Immersed parts materials Sensor: AISI316, FEP, FPM, PVDF, NBR70 Cable: FEP

EMC Emission Immunity

IEC/EN 61000-6-3 IEC/EN 61000-6-1

Ex-classification

Special conditions (X)

ATEX

II 1 G [Ex ia] IIB/IIC T4 (Ta = -40 °C…+90 °C) T5 (Ta = -40 °C…+85 °C) T6 (Ta = -40 °C…+70 °C) VTT 03 ATEX 090X

Electrical parameters for 80 m cable length

IIB

IIC

Ui = 30 V Ii = 146 mA Pi = 1095 mW Ci = 9 nF Li = 170 µH Ui = 30 V Ii = 101 mA Pi = 758 mW Ci = 9 nF Li = 170 µH

Manufacturing year: Please see the serial number on the type plate

xxx x xxxxx xx YY x where YY = manufacturing year (e.g. 13 = 2013)

NOTE ! The measurement is based on changes in the sensor’s capacitance – variations in the dielectric constant or electrical conductivity of the medium being measured will affect measurement results.



4 INSTALLATION

WBS 3000 sensors may be installed in a Zone 0/1/2 hazardous area. Relevant standards shall be observed:IEC/ EN 60079-25 Electrical apparatus for potentially explosive atmospheres - Intrinsically safe electrical systems "i", IEC/EN 60079-14 Installations in potentially explosive atmospheres and local regulations, if any.

WARNING! Includes light alloy parts1 If the sensor is equipped with a gas tight mounting assembly and aluminium connection box the enclosure is of light metal so there may be sparks, if the enclosure is subjected to friction or impact.

WARNING! Contains plastic particles! The non-conducting surface of the sensor element and the cable may be charged by the flow of non-conducting media, so there may be electrostatic hazard.

4.1 Suspended version

Whenever it is possible, the most cost-effective way to install the WBS 3000 is to hang it with a min. 8 mm diameter steel wire between the top and the bottom of the vessel or in separate still pipe.

The vertical position of the sensor is chosen according to the actual bottom water range.

The suspension wire shall be fastened with two wire locks to the WBS3000's suspension bracket in case it hasn’t been already done by the factory - see figure nr. 2. Never suspend the sensor with it's cable!

NOTE! The WB S 3000 must be anchored to the vessel bottom in order to avoid damages caused by sensor swinging and rotation in the vessel.

Figure 2. Suspended version of WBS 3000; lower end.



Figure 3. WBS 3000 cable clamp.

When ordered the WBS 3000 delivery includes cable clamps (figure nr. 3) according to ordered sensor cable length. When installing the probe, connect the clamps on approximately 5 m intervals. Cut out the extra tail from every cable tie and make sure it touches only the NBR tube shield and not directly the sensor cable.

NOTE! Connect the cable clamps so, that the sensor cable hangs loosely compared to the suspension wire and throughout the installation be careful not to damag e the sensor cable insulation in any way.

Figure 4. WBS 3000 mechanical installation.

Figure nr. 4 describe the gas-tight mounting of the wire’s and cable’s upper end.

Please, follow the local legislation concerning int rinsically safe installations!



4.2 Flange mounted version

Sometimes, e.g. in vessels with floating tops, it can be more cost-effective to side-mount the WBS 3000 with a flange in an angle (45o angle is recommended). An 8" ANSI 150 lbs. flange, material stainless steel AISI316 is also recommendable.

The active length of the sensor has it's upper-most tip by the flange.

Figures nr. 5 and nr. 6 describe the flange mounting.

Figure 5. A fuel oil vessel with a floating top. WBS 3000 installation with a 8” flange

Figure 6. One example of the WBS 3000 flange mounted version.



5 ELECTRICAL CONNECTIONS

The wire insulation color code in the free cable end:

Figure 7. Cable color coding.

In explosion-hazardous installations, the sensor must be connected to an active Ex-barrier, which is located in the safe area, see figure 8.

Facilities according to individual tank farms may vary. Therefore, the electrical connections can be done in different ways.

Make sure that maximum allowed connection values Co, Lo and Lo/Ro of the Ex-barrier match with the WBS 3 000's parameters Ci and Li.

Figure 8. Installation in explosion hazardous area with active Ex barrier.

Figure 9. Electrical connections with shield not connected.

Figure 9. refers to a case, where the WBS 3000's cover tube is grounded via suspension wire to the vessel's equipotential ground. The cable shield is internally connected to the cover tube so here, the cable shield is left unconnected.

Always check and follow local legislation before in stallation!



5.1 WBS 3000 Power supply requirements

The two wire transmitter needs a minimum of 13 V at its input at 20 mA ouput current to function properly.

E = power supply voltage unloaded

Ri = power supply internal resistance

RL = line and load resistance

UTr = voltage over transmitter input

UTr = E - I x (Ri+RL)

UTmin = 13 V

Example

E = 24 V

I = 20 mA

Maximum allowable total resistance

−

=24 − 13

0,02=

11

0,02= 550Ω = R + R

If total resistance exceeds 550 Ω , the transmitter cannot give full output current.



6 APPROVALS

The WBS 3000 is issued a certificate of conformity by Technical Research Centre of Finland (VTT) according to the European standars IEC/EN 60079-0, IEC/EN 60079-11 and IEC/EN 60079-26. It meets the requirements with the marking of the type of protection mentioned in technical data (chapter 3).

See the appendix copy of the certificate of conformity.

7 WARRANTY

The warranty is valid 12 months.

8 TROUBLE-SHOOTING

Service, inspection and repair of Ex -apparatus needs to be done according to standards IEC/EN 60079-17 and IEC/EN 60079-19.

Symptom: the output signal stays constant between 4 mA and 20 mA and does not correspond to real circumstances.

Possible reasons: dirt has clogged between electrode and reference tube. - Clean the sensor: Release the cover tube of the sensing element, which is detached in the probe with two screws. Clean the cover tube and the sensing element with warm water. NOTE! Make sure not to damage the FEP insulation of the sensing element.

Symptom: the analog signal is constantly (or exceeds) 20 mA and does not correspond real circumstances.

Possible reason: the FEP insulation of the electrode has a leakage or the cast-in transmitter is damaged due to too high temperature. - Replace the sensor with a new one.

wbs 3000 - · pdf filesignal output is proportional to interface level so, ... figure 3. wbs...

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