Sitron-Manual SC 404

INSTALLATION, OPERATION ANDMAINTENANCE INSTRUCTIONS

Capacitive Level Sensor SC 404

2Phone (516) 935-8001 / Fax (516) 935-6001

3456

7, 89, 10

11121314

Contents

Introduction .............................................................................Features & Dimensions .......................................................... Handling .................................................................................Installation .............................................................................. Wiring diagram ...................................................................Calibration ..........................................................................Maintenance ...........................................................................Technical specifications ..........................................................Trouble shooting .....................................................................Ordering information ..............................................................

Introduction

3

SC 404

The wide range of applications for RF analog level measurement probes (such as liquids, pastes, solids and granules), requires attention in selecting the correct level probe and installing it in the proper location. The probe is the primary measuring element and must be capable of producing enough capacitance variance as it becomes submerged in the measured product. To cater to all applications, Sitron's probes are offered with different designs and features. The success of how the probes are applied depends on these important factors:

A) Materials that are conductive can cause a short circuit between a bare stainless steel probe and the tank wall. As the liquid level drops, the probe remains wetted, providing a conductive path between the probe and the tank wall. The faster the level changes, the more likely this false indication is to occur. For this situation, we recommend the use of Teflon or other types of insulator coatings on the rod's surface.

B) Materials build-up also affects the accuracy of RF capacitive measurements, and therefore additional adjustment to the probe's sensitivity is recommended.

Housings must also be compatible with the requirements for hazardous, wash-down, wet, and/or dusty environments. Explosion-proof environments may require the housing to be certified. In addition, the active probe might need to be intrinsically safe or have an intrinsic safety barrier.

The electronic circuitry of the probe performs several functions such as rectifying and filtering the incoming power, generating the radio frequency signal, measuring the changes in current flow, analog signal generators and display meters. The circuitry is provided with potentiometer adjustments for setting sensitivity that is located in the housing of the probe. These adjustments give an added level of fine-tuning which enable our customers to control the probes sensitivity with greater accuracy.

4

Features and Dimensions

Phone (516) 935-8001 / Fax (516) 935-6001

Wide range of applications/industries I.e. water, oils, corrosives, solids, powders, grains, etc. Functions on conductive as well as non-conductive medias No moving partsRugged construction Accurate and reliable measurement Unaffected by coating media or aggressive products Can operate at high temperatures and pressure

L

3/8”

L

3/8”

3 1/2” ( 88 mm )

2 1

/2”

( 6

4 m

m )

SC 404 SC 404 EX

3 1/2” ( 88 mm )

4 1

/4”

( 11

4 m

m )

5

Handling

Do not turn or handle by the housing

Seal the threadwith teflon tapebefore screwing

Use the correct tool to screw the switch

Installation

Phone (516) 935-8001 / Fax (516) 935-6001

INCORRECT CORRECT

The SC404 level sensor must be installed utilizing the type of connection provided. The tank must be free from turbulence or vortices throughout use. When tightening the sensor, use only use the 316S.S. hexagon fitting to achieve a seal, do not twist with the body of the sensor.

Note: As achieving a proper seal it is very important for high pressure and explosion proof applications that care should be taken when tightening the connection.

When installing the sensor either directly to the tank, or utilizing a connection, the capacitance probe should be mounted on the top of the tank, so that the rod stays parallel to the tank wall. Positioning the probe closer to the tank wall than to the center of the tank and away from the point where the medium enters the tank is preferable (see drawing below). This will reduce the chance of false reading when the tank is being filled. It is important however, that the probe does not touch the tank wall or any structural elements within the tank. In addition, the probe should not be mounted where material can form a bridge between the rod and the tank wall.

Care should also be taken when handling and installing sensors with coated rods. Any scratch can affect the performance of the sensor.

6

7

Wiring Diagram

Electrical Connection:

The electrical connection is available in a plug-in three way terminal block that can be removed for wiring connections more easily. Use only shielded cable to wire these connections.

The power supply required is 12...30Vdc

+ Positive power supply - Negative power supply (4-20mA) Ground

Important: Do not ground the negative. There are several types of PLC's configurations and some of them have the negative grounded internally. In this case, a galvanic isolator must be used along with the probe to distinguish both signals (negative and ground).

Remove the enclosure lid (Note: the screws are self-retaining)

Use the cable gland to seal and protect the electronic circuit inside the enclosure.

The housing may be rotated after tightening to leave the cable gland in a suitable position.

++--

U = 12 … 30 VdcU = 12 … 30 Vdc

Wiring Diagram

L1L1

2 3 41

A B C

SpanZero

SC 404

PowerSupply

IN

4...2

0 m

A

4...2

0 m

A

ISO

42

0

Zo

ne

0O

UT

1112

12

++__

++__

mmx

Galvanic Isolator

22 ... 24 DC

__

++PowerSupply

Electrical connection using the Galvanic Isolator

L1L1

2 3 41

A B C

SpanZero

SC 404

4 ... 20 mA

0 ... 100 %

PowerSupply

Connect directly to the power supply

L1L1

2 3 41

A B C

SpanZero

+-

SC 404

12 … 36 Vdc

Sensitivity adjustmentSensitivity adjustment

Zero and SpanAdjustment

Phone (516) 935-8001 / Fax (516) 935-6001 8

9

Calibration

The dielectric value varies according to the product, temperature, pressure, rod's length and shape of the tank. Because of these variations, the parameters of the capacitive probe need to be adjusted according to each application.

The SC 404 has 4 stages of sensitivity that can be adjusted by a selective switch. Each stage has 3 subdivisions (A, B, C) to be combined with the selective switch. Check the values on the chart below according to your application.

Capacitange range:

1 1600pF to 5500pF A - 3750 to 5500pFB - 2500 to 3750pFC - 1600 to 2500pF


3 100pF to 330pF A - 225 to 330pFB - 150 to 225pF C - 100 to 150pF


L1L1

2 3 41

A B C

SpanZero

++--

SC 404

Selectivity switch

12 … 36 Vdc

Positions A,B,C

Adjust of zero and span

10Phone (516) 935-8001 / Fax (516) 935-6001

Calibration

Minimum Adjustment (4mA):

Maximum Adjustment (20mA):

1) Drain the tank to minimum level (0% - level).2) Select the switch 1,2,3, or 4 and positions A, B or C. It is recommended

to begin with switch 1 and position A. 3) Use the Zero potentiometer to set the current value for the actual level

to 4mA. Turn the potentiometer clockwise to increase current. Turn the potentiometer counter-clockwise to decrease current.

It is recommended that an ampere meter be connected according to the figure below to monitor the current value during the calibration.

1) Fill up the tank to maximum level (100% - level).2) The switch should be in the same position as adjusted to 4mA.3) Use the Span potentiometer set the current value for the actual level to

20mA. Turn the potentiometer clockwise to increase current. Turn the potentiometer counter-clockwise to decrease current.

It is recommended that an ampere meter be connected according to the figure below to monitor the current value during the calibration.

If the current is lower than 20mA, it is necessary to increase the sensitivity by selecting the next level of the switch (#2). If the current still remains lower than 20mA, continue on to the next level until you achieve 20mA.

With the 20mA signal adjusted, keep the switch on the same position and adjust the minimum level to 4mA one more time.

After this stage, set-up is complete.

L1L1

2 3 41

A B C

SpanZero

SC 404

12...30Vdc

++

Positive

Negative

Ampere meter

++

--

--

11

Maintenance

When cleaning the rods use a soft brush or any other similar object.

PROBES:

Care should be taken when handling and installing transmitters with coated rodsto avoid scratching them.Scratching the coating could interfere with the probe performance.

12

Technical Specifications

Phone (516) 935-8001 / Fax (516) 935-6001

SC 404 SC 404 EX

Application

OperatingVoltage

Current Consumption

Adjustment

Sensitivityrange

Frequencyoscilation

Zero & SpanPotentiometer

Zero & SpanPotentiometer

4...20mA (2 wires) 4...20mA (2 wires)

12...30 Vdc 12...30 Vdc

100 to 5500pF 100 to 5500pF

400K Hz 400K Hz

-- --

Continuous level measurement for liquids solids and granular

Continuous level measurement for liquids solids and granular

Output

Repeatability

Level indication

Max pressure 290 PSI (20 Bar) 290 PSI (20 Bar)

IP 65 Eex II B,C

Accuracy 0,5% 0,5%

+/- 1mm

----

+/- 1mm

Enclosure material

Glass fillednylon

Alluminum Die CastExplosion Proof

Wetted material

316 SS 316 SS

Class Protection

Processconnection

3/4” to 1 1/2” BSP or NPTflange or sanitary connections

3/4” to 1 1/2” BSP or NPTflange or sanitary connections

Operatingtemperature

14 to 248º F(-10 to 120ºC)

14 to 248º F(-10 to 120ºC)

MODELS

Electricalconnection

½”NPT Cable gland or M12 connector

1/2” or 3/4” NPT

13

Trouble shooting

Does not signal

The signal is overthan 22mA

Fault

Capacitance short

Noise outputThe signal is notfixed

No powerWrong connection

Cause

Check the ground connection

Check if the probe is coatedfor conductive mediums

Check power supplyCheck the polarity of the power

Solution

Ordering Information

Phone (516) 935-8001 / Fax (516) 935-6001 14

Code

SC404SC120

Code

1

2

3

4

5

6

78

Code

B

NX

Code

20

40

60X

Code

NYEX

Code

C

M

1/23/4

Code

PTFE

0X Other - Specify

NOTE:

RODS MUST BE COATED WHEN USING THE PROBE WITH CONDUCTIVE MEDIUMS.

CodeCN200

Code

24

1123

Note:

CONTINUOUS LEVEL MEASUREMENT

Glass filled nylonAluminum die cast

3/4"NPT (alum.enclosure only)

Electrical Connection

Cable entry

M12 connector

1/2"NPT (alum.enclosure only)

L=40" (L=1000mm)

L=60" (L=1500mm)Other - Specify

Enclosure

NPTNot a thread

Rod's Length

L=20" (L=500mm)

Flange 4" ANSI, 150lb. 316 S.S.Other - Specify

Type of Thread

BSP

ORDERING INFORMATION

Probe to be used along with CN200 transducer (see specs. below)

3/4" Thread

1" Thread

Coating

Teflon

None

Specifications

Supply Voltage: 12...30VDC Output: 4-20mA (2 wire)

Process Connection

1 1/2" Thread

1 1/2" Tri-Clamp

Flange 2" ANSI, 150lb. 316 S.S.

Flange 3" ANSI, 150lb. 316 S.S.

SpecificationsTransducer to be used along with probe SC120

Supply Voltage

24 VDC + - 10%

The CN200 output is: 2 relay (SPDT) 5A max. 250VAC, 4-20mA (2 wire) and 0-5VDC for all options.

115 VAC230 VAC

Sitron-USA, Inc.PO Box 7000

New York, NY 10128Tel: (516) 935-8001 / Fax:(516) 935-6001

e-mail: [email protected]: www.sitron.com

Sitron-Manual SC 404

Documents

Transcript of Sitron-Manual SC 404