E X P E R T I S E S O L U T I O N S S U S T A I N A B I L I T Y

3.887.5275.200 Issue 1 - 2014

© Copyright 2014

SMART HART® Pressure Transmitter Series LD256

Installation and Maintenance Instructions

1. Safety information

2. General product information

3. Installation

4. Configuration

5. Spare parts

The PED Directive 97/23/EC is repealed and replaced by the new PED Directive 2014/68/EU with effect from 19 July 2016.

The ATEX Directive 94/9/EC is repealed and replaced by the new ATEX Directive 2014/34/EU with effect from 20 April 2016.

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ATTENZIONE Lavorare in sicurezza con apparecchiature

in ghisa e vaporeWorking safely with cast iron products on steamInformazioni di sicurezza supplementari - Additional Informations for safety

Lavorare in sicurezza con prodotti in ghisa per linee vaporeI prodotti di ghisa sono comunemente presenti in molti sistemi a vapore. Se installati correttamente, in accordo alle migliori pratiche ingegneristiche, sono dispositivi totalmente sicuri. Tuttavia la ghisa, a causa delle sue proprietà meccaniche, è meno malleabile di altri materiali come la ghisa sferoidale o l’acciaio al carbonio. Di seguito sono indicate le migliori pratiche ingegneristiche necessarie per evitare i colpi d'ariete e garantire condizioni di lavoro sicure sui sistemi a vapore.

Movimentazione in sicurezzaLa ghisa è un materiale fragile: in caso di caduta accidentale il prodotto in ghisa non è più utilizzabile. Per informazioni più dettagliate consultare il manuale d'istruzioni del prodotto.Rimuovere la targhetta prima di effettuare la messa in servizio.

Working safely with cast iron products on steamCast iron products are commonly found on steam and condensate systems. If installed correctly using good steam engineering practices, it is perfectly safe. However, because of its mechanical properties, it is less forgiving compared to other materials such as SG iron or carbon steel.The following are the good engineering prac-tices required to prevent waterhammer and ensure safe working conditions on a steam system.

Safe HandlingCast Iron is a brittle material. If the product is dropped during installation and there is any risk of damage the product should not be used unless it is fully inspected and pressure tested by the manufacturer. Please remove label before commissioning

VaporeSteam

Flusso Flow

Esempi di esecuzioni corrette ( ) ed errate ( ) sulle linee vapore:Steam Mains - Do's and Dont's:

Flusso Flow

Prevenzione dai colpi d’ariete - Prevention of water hammerScarico condensa nelle linee vapore - Steam trapping on steam mains:

Intervalli di 30÷50 m. intervals

Pendenza - Gradient 1:100VaporeSteam

Gruppo di scaricoTrap set

Condensa - Condasate

Pendenza - Gradient 1:100

Gruppo di scaricoTrap set

Gruppo di scaricoTrap set

Condensa - CondasateCondensa - Condasate

VaporeSteam

Prevenzione delle sollecitazioni di trazionePrevention of tensile stressingEvitare il disallineamento delle tubazioni - Pipe misalignment:

Installazione dei prodotti o loro rimontaggio post-manutenzione:Installing products or re-assembling after maintenance:

Evitare l’eccessivo serraggio.Utilizzare le coppie di serraggio

raccomandate.Do not over tighten.

Use correct torque figures.

Per garantire l’uniformità del carico e dell'allineamento, i bulloni delle flange devono essere serrati in modo

graduale e in sequenza, come indicato in figura.Flange bolts should be gradually tightened across

diameters to ensure even load and alignment.

Dilatazioni termiche - Thermal expansion:Gli esempi mostrano l’uso corretto dei compensatori di dilatzione. Si consiglia di richiedere una consulenza specialistica ai tecnici dell’azienda che produce i compensatori di dilatazione.Examples showing the use of expansion bellows. It is highly recommended that expert advise is sought from the bellows manufacturer.

GuideGuides

Distanza breveShort distance

Punto di fissaggioFixing point

Movimento assialeAxial movement

Distanza media Mediumdistance

Tiranti limitatoriLimit rods

Piccolo movimento

lateraleSmall lateral

movement

Piccolo movimento lateraleSmall lateralmovement

Ampio movimento

lateraleLarge lateral

movement

Ampio movimento lateraleLarge lateralmovement

GuideGuides

GuideGuides

GuideGuides

Punto di fissaggioFixing point

Tiranti limitatoriLimit rods

Movimento assialeAxial movement

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1. Safety informationSafe operation of these products can only be guaranteed if they are properly installed, commissio-ned, used and maintained by qualified personnel (see Section 1.11 on this document) in compliance with the operating instructions. General installation and safety instructions for pipeline and plant construction, as well as the proper use of tools and safety equipment must also be complied with.

1.1 Intended useThe trasmitters object of the present instructions comply with the directive ATEX 94/9/CE and are characterized by the following motodhds of protection:

II 1G Ex ia IIC T6They are suitable for installation in Zone 0, Zone 1, Zone 2.For connections and installation refer to this manual.

1.2 AccessEnsure safe access and if necessary a safe working platform (suitably guarded) before attempting to work on the product. Arrange suitable lifting gear if required.

1.3 LightingEnsure adequate lighting, particularly where detailed or intricate work is required.

1.4 Hazardous liquids or gases in the pipelineConsider what is in the pipeline or what may have been in the pipeline at some previous time. Con-sider: flammable materials, substances hazardous to health, extremes of temperature.

1.5 Hazardous environment around the productConsider: explosion risk areas, lack of oxygen (e.g. tanks, pits), dangerous gases, extremes of temperature, hot surfaces, fire hazard (e.g. during welding), excessive noise, moving machinery.

1.6 The systemConsider the effect on the complete system of the work proposed. Will any proposed action (e.g. closing isolation valves, electrical isolation) put any other part of the system or any personnel at risk? Dangers might include isolation of vents or protective devices or the rendering ineffective of controls or alarms. Ensure isolation valves are turned on and off in a gradual way to avoid system shocks.

1.7 Pressure systemsEnsure that any pressure is isolated and safely vented to atmospheric pressure. Consider double isolation (double block and bleed) and the locking or labelling of closed valves. Do not assume that the system has depressurised even when the pressure gauge indicates zero.

1.8 TemperatureAllow time for temperature to normalise after isolation to avoid danger of burns.

1.9 Tools and consumablesBefore starting work ensure that you have suitable tools and/or consumables available. Use only genuine Spirax Sarco replacement parts.

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1.10 Protective clothingConsider whether you and/or others in the vicinity require any protective clothing to protect against the hazards of, for example, chemicals, high /low temperature, radiation, noise, falling objects, and dangers to eyes and face.

1.11 Permits to workAll work must be carried out or be supervised by a suitably competent person. Installation and operating personnel should be trained in the correct use of the product according to the Installation and Maintenance Instructions. Where a formal ‘permit to work’ system is in force it must be complied with. Where there is no such system, it is recommended that a responsible person should know what work is going on and, where necessary, arrange to have an assistant whose primary responsibility is safety. Post ‘warning notices’ if necessary.

1.12 Electrical workBefore starting work study the wiring diagram and wiring instructions and note any special requirements.Consider particulary: mains supply voltage and phase, local mains isolation, fuse requirements, earthing, special cables, cable entries / cable glands, electrical screening .

1.13 CommissioningAter installation or maintenance ensure that the system is fully fuctioning.Carry out test on many alarms or protective devices.

1.14 DisposalUnwanted equipment should be disposed of in a safe manner.

1.15 Returning productsCustomers and stockists are reminded that under EC Health, Safety and Environment Law, when returning products to Spirax Sarco they must provide information on any hazards and the precautions to be taken due to contamination residues or mechanical damage which may present a health, safety or environmental risk. This information must be provided in writing including Health and Safety data sheets relating to any substances identified as hazardous or potentially hazardous.

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Main dimensions and sensor's reference

Cod. Nom. Rangebar

Spanmin/max

bar

Range Limitsmin/max

barOverpressure

(max bar)

D 0/0,35 0,022/0,35 -0,35/0,35 2

E 0/1 0,06/1 -1/1 6

F 0/2,5 0,156/2,5 -1/2,5 10

G 0/5 0,31/5 -1/5 16

H 0/10 0,625/10 -1/10 30

K 0/30 1,875/30 -1/30 75

L 0/100 6,25/100 -1/100 150

M 0/200 12,5/200 -1/200 500

N 0/400 25/400 -1/400 600

2. General product information

M20x1,5

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Product SheetOverviewLD256 series SMART pressure transmitters are microprocessor based instruments that combine the analog signal advantages (4-20mA) together with the flexibility of digital communication using HART® protocol. They can be remotely configured by a universal hand held terminal (HHT).Moreover, it is possible to locally configure the instruments (zero and span) by means of 2 pu-shbuttons and to display the data on the wide LCD display. The LD256 transmitters, complete with diaphragm in AISI 316, measure relative pressure with spans from 0,022 to 400 bar. The pressure measuring element is a piezoresitive sensor. It is possible to choose a variety of sensors to satisfy all process conditions. The Spirax Sarco measuring cell contains the sensor and transmits pressure to the electronics. Thermal drift is compensated using the temperature signal generated by a PTC thermistor integrated in the sensor itself. Based on these readings the microprocessor generates the 4-20mA analog output "two wires system" and displays the pressure measurement on the LCD.Some of the main characteristics of this microprocessor-based transmitter, are:- Wide rangeability.- Automatic temperature compensation.- Digital communication using HART® protocol.

Functional DataWith reference to the following, please note these definitions:Nominal range: (referred to the sensor mounted in the instrument) the measured pressure range for which the sensor has been designed. Defined as a minimum and maximum value.Nominal span: the interval between the minimum and maximum values of the sensor nominal range. The span is a single number.Measuring range: the minimum and maximum range values for which the transmitter is to be calibrated.Measuring span: the interval between minimum and maximum values of the measuring range.Input scale initial value or zero input: minimum pressure value within in the measuring range.Input full scale value: maximum pressure value within in the measuring range.

Transmitter parametersThe parameters that are available for display and setting are:Measuring span: possibility to change from 6,25% to 100% of the nominal span.Zero adjustment: digital calibration ± 15%.Linearity adjustment: 8 points within the nominal range.Low/upper range values: they can be set within the nominal range provided that the span greater than minimum span.Damping: digitally adjustable from 0 to 15 sec. (minimum response time ~ 0,1 sec.).Reverse output: automatically obtained via software.Transfer function: linear/square root via software.Self test: in case of malfunction the analog output is forced to the fail-safe state of 3,8mA or 23,2mA.Measuring units: 14 different pressure units or % of the measuring span, selectable via software.

Physical characteristicsPower supply: 12,5-30 Vdc with no loadOutput signal:Analog 4-20mA, 2 wires.Digital using HART®

Ambient ConditionsTemperatureProcess fluid: -60 ÷ +85°C (with finned arm max 150°C)Housing: -40 ÷ +85°CHandling and storage: -40 ÷ +90°CRelative Humidity: 0 a 100% R.H.LCD display reading: -10 ÷ +70°C

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PerformancesUnless otherwise stated the performance specifications refer to ambient temperature = 20°C and nominal span. Unless otherwise stated, all errors are shown as a percentage of nominal spanAccuracy rating: guaranteed within the following limits:Resolution: ± 0,01%.Accuracy: ± 0,1% including non linearity, repeatability and hysteresis errors.Dead band: negligible.Influence of Operating conditionsThermal drift: referred to -10 ÷ +65°C range.Zero: ± 0,1%/10°K. Span: ± 0,1%/10°K at nominal range.Power supply effect: Negligible between 12,5 and 30 V d.c.Physical specificationsProcess wetted parts: Diaphragm in AISI 316 L/Hastelloy C - process chambers, adapters, drain and vent plugs AISI 316 - gaskets PTFE + Viton + bolts carbon steel / AISI 304.Housing: die cast aluminium alloy AL UNI 3571 finished with epoxy resin (RAL 5010).Filling fluid: silicone oil.Nameplate: stainless steel, fixed on housing.CalibrationStandard: at nominal range, direct action.Optional: at the conditions specified with the order.Environmental protection: the transmitter is dust and sand tight and protected against sea waves effects as defined by IEC IP 66. Suitable for tropical climate operation as defined in DIN 50.015.Process connections: ½" NPT M.Electrical connections: two entries on electronic housing, M20 x 1,5 and cable gland PG 13,5 for 7 to 12mm diameter cable.Terminal board: 2 terminals for signal wiring up to 1,5 mm2 (14 AWG). Connection for ground and cable shield.Mounting position: any position.Net weight: 1.4 kg. approx.Explosion ProtectionEquipment and protection system ATEX 94/9/CEIntrinsically safetyEx ia IIC T6 with Tamb -40 °C ÷ +60°CEx ia IIC T5 with Tamb -40 °C ÷ +75°CGroup II class 1G suitable for zone 0,1,2 - EN60079-10.Electromagnetic CompatibilityConforms to the standard CEI EN 61326-1 (1997) in accordance with 89/336/EEC and following modifications.

Bench Calibration Set-up

Pressuresource

Test gauge

Indicator

Powersupply

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Standard specificationsThe electronic transmitters Series LD256 are described in Products Sheet 7E.171. In these data sheets information can be found on: Functional Data - Operating Conditions - Performances - Ope-rating Influences - Physical Specifications - Certificates - Codification - Dimensions.

OverviewLD256 series transmitters measure relative pressure in ranges from 22 mbar up to 400 bar.The pressure measuring element is a piezoresistive sensor. It Is possible to choose between sensors to satisfy the process conditions. The Spirax Sarco's Measuring Cell generates a signal corresponding to the actual pressure and is completed with a PTC thermistor which also transmits the temperature of the measuring cell to the electronic system. On the basis of these two values and of the configurated parameters the microprocessor based electronics (Fig. 1) generates a standard output signal (4 to 20 mA, Iwo wires system) and displays the measurement on the LCD. Moreover LD256 transmitters contain (depending on Hw and SW release) a PID (Proportional, Integral, Deri-vative) Control algorithm that allows to use the 4 to 20 Ma.The functional block diaphragm of the transmitter is shown in the figure below.

Fig. 1 - Block Diagram

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3. Installation3.1 Instrument Identification Instrument data can be found on the nameplate fixed to the top of transmitter housing. The Serial Number that must be quoted at the occurrence of specific requests to the manufacturer. Fig.2 shows both sides of the housing with covers removed.

3.2 Transmitter mounting The transmitters LD256 are supplied for direct mounting.- Check whether instrument’s operating conditions are within the limits as reported in the technical

specifications sheets and/or label.- Make sure that the operating conditions are compatible with the specification given to the manufacturer.- Never install standard instrument under the sun or in any other location which could cause direct overheating through radiation.- For measurement in the presence of particularly hot liquids (e.g. steam) install the instrument

on a siphon (as in the case of manometers) or make sure that the instrument is supplied with a suitable seal.

- For viscous liquids or those containing solid particles in suspension make sure that the connection to the process is a suitable one in order to avoid clogs.

- Pressure transmitters are calibrated upright with sensors turned down (unless otherwise specified).Any different position introduces a variation of output zero value. Maximum variation (offset) is equivalent to 20mmH2O in pressure.Refer to dimensional drawing for details, the position of the housing has no effect on the instrument operation. In particular, before shipping the instrument is locked (Fig. 3). To obtain a good orientation of the case it is necessary to unscrew the stop nut placed under the case. Turn the case in the new position and screw the nut again.

3.3 Electrical connectionUnder the rear cap are placed the terminals reporting the electric polarity (+/-). Insert the power supply cable in to the housing through one of the two M20 x 1,5 openings. Device is protected from accidental inversion of polarity. For a better use is recommended a twisted pair cable (22 AWG min).Avoid placing instrument near devices powered in AC or Switching. Connect ground-tap of the instrument to the local common earth (PE). For shielded cables, earth the shield at the power supply ground only.

Warning: impedance of the cables defines the possible maximum length for digital communication. It's recommended using cable with a low impedance. The maximum length of the point to point connection, with a load of 250 ohm and single twisted cable 22 AWG-207 pF/m it's about 1000 meters.

The maximum connection length for the analog signal only is limited by the loads (connected devices and cable) present in the current loop.

Fig. 2 - LD256 Series top work Fig. 3 - Mounting

Front:Electronic Module

Back

Nut

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To obtain output signal of 4-20 mA, you have to determine the minimum supply voltage as a function of the load relation: see below figure. From the following formula you can achieve the right minimum value of supply voltage:

Vcc = 0.023xR + 12.5The power supply source to assure a minimum current value of 24 mA.Where: R = output load..

Warning: for the digital communication to function properly, a minimum 250Ω load must be present in the loop.

Fig. 4 - Power supply/load

Fig. 5 - Transmitter wiring

Load

(OH

M)

Power supply (V)

Digital Communication and 4-20 mA

Not Operative Area

4-20 mAOnly

Controlleror

Recorder

Power Supply

Indicator

Intrinsic Safety Barrier

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3.3.1 Point to point connectionMake connection as shown in Fig.6

Fig. 6 - Point to point connectionRL=250 OHM min.Connection to the Master for digital communication is possible at points A-B or B-C.

3.3.2 Multidrop connection (Digital signal only)Make connection as shown in Fig.7Connection to the Master for digital communication is possible at points A-B or B-C. in the Fig. 7

Warning: pay attention that for a right working of the digital communication a minimum load of 250 ohm is necessary.

Warning: When more transmitters are connected on the same line the current standing on the resistor (250-ohm) is equal to 4mA x N of connected instruments

This could cause a high electric potential. Be sure power supply is sufficient.

Note: At maximum 15 transmitters could be connected in parallel on the same line.

3.4 Safety instructions3.4.1 GeneralInstruments of the LD256 series are Transmitters of relative pressure. They are devices with solid state electronics whose operation is based on piezoresitive sensors. They measure pressures of liquids, gas and vapors with nominal ranges from 22 mbar up to 400 bar and transmit an current output signal 4-20 mA proportional to the measured pressure. They can also be used to measure level in open or closed tanks or for measures of flow measuring the differential pressure on a calibrated orifice.

Fig. 7 - Multidrop connection

Power supply

Power supply

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3.4.2 Premise (Intrinsically safety)The series LD256 are used for measures of pressure, this series are manufactured only for the employment in areas with presence of potentially explosive atmospheres. The transmitters object of the present instructions are characterized by the following methods of protection: Ex ia II C T6 with T amb -20 + +40°C Ex ia II C T5 with T amb -20 + +55°C Ex ia II C T4 with T amb -20 + +80°C*The indications contained in the present safety instructions must be observed together with the instructions brought in the operator manual.* Note: for use with T amb.> 60°C please see the table "Electrical parameters related to Intrinsic Safety" at par. 2.4.3.4

3.4.3 Installation3.4.3.1 Fitness of the transmitter for the installation areaIn case of use in areas with danger of explosion, it must be verified that the identified type of transmit-ter fits for the classification of the zone and for the presence of flammable substances in the plant.The safety essential requisite against the risk of explosion in the classified areas are fixed from the European Directives 94/9/CE of March 23 rd 1994 (as far as it concerns the apparatus) and 1999/92/CE of December 16 th 1999 (as far as it concerns the plant).

3.4.3.2 Intrinsically safety data definitions

II 1G Transmitter for surface plants with presence of gas or vapors, Group II, category 1, fit for zone 0 and with redundancy for zone 1 and 2

Ex ia Intrinsically Safe transmitter, category "ia"IIC Group IIC apparatus, fit for substances (gas) of group IIC

T6, T5, T4 Temperature Class of the transmitter (maximum temperature)Conformity mark to European Directives applicable to the apparatus

Conformity marking to 94/9/CE Directive and technical rules

CESI YY ATEX NNN Name of the laboratory that released the EC type-examination certificate;YY=Year; NNN=certificate number

0722 Identifying Number of the notified body (CESI) that assess the quality system of the manufacturer

T. amb Ambient minimum and maximum temperatureUi, li, Pi, Ci, Li Maximum Input parameters of the apparatus (related to intrinsic safety)

Note:a) - the transmitters for the group IIC also fit for gas groups IIB and IIA;b) - the transmitters with class of temperature T6 also fit for all the substances with higher class of

temperature (T5, T4, T3, T2, T1);c) - the transmitters with class of temperature T5 also fit for all the substances with higher class of

temperature (T4, T3, T2, T1);d) - the transmitters with class of temperature T4 also fit for all the substances with higher class of

temperature (T3, T2, T1);e) - the choice of the associated apparatus must be made on the base of the maximum input

parameters of the transmitter.

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3.4.3.4 Electrical connections (Intrinsically safety)For the electrical connections please follow the instructions brought in the operator manuals taking care that for the use in classified areas it is necessary to foresee the use of associated apparatuses ( e.g. safety barriers), certified according to the standard EN 50020, with output electrical characteristics compatible with the maximum input parameters (brought on the plate) of the certified transmitter. The evaluation of the system constituted by the associated apparatus, the transmitter and the cables of connection must be done by experienced personnel only and must match the requisite of the stan-dard EN 50039 relative to the intrinsically safe systems. For the correct installation it is necessary to follow the safety instructions of the selected associated apparatus.

Electrical parameters related to Intrinsic SafetyParameter For T amb < 60°C For T amb < 80°C

Maximum input voltage Ui 30 V 25,2 VMaximum input current Ii 100 mA 100 mAMaximum input power Pi 0,75 W 0,62 WMaximum internal capacitance Ci 10 nF 10 nFMaximum internal inductance Li 0 H 0 H

3.4.4 Control and MaintenanceThe verifications and the maintenances of the transmitters must be done according to the criterions of the standard EN60079-17.

3.4.5 Instrument ServiceIn case of malfunction or damage it is advised to contact Spirax Sarco service department.

3.4.3.3 Additional Warnings for installationFor the correct installation refer to the chapter operator manual and to sketches brought there.The process connection must be realized in such a way that guarantees the hold at the maximum working pressure and temperature. Do not overcome the maximum pressure and temperatures indicated in the technical data sheet of the selected model. When the device is connected to the process it can be submitted to high pressures and temperatures. To avoid accidents subsequent to sudden discharge of pressure and/or to contact with dangerous or flammable fluids it is necessary to take the maximum attention when the device is taken off, heated or repaired, verifying that it is isolated from the process and is not submitted to pressure and/or temperature.

R (Ohm)

1070

837

600

170

12 30 35 V supply (Vcc)

Exi + HART®Exi

Exi

NonExi

Operative area

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3.5 Pressure measurementThe transmitter LD256 may be used for pressure and level measure on open tank in the ranges showed in the table on first paragraph of this manual and mounting. On Fig.9 and 9.1 it is shown the simplest mounting, direct on piping.

Warning: the diaphragm seal must be always covered by the liquid.

Fig. 9

Fig. 9.1

Liquid

Gas

Vent

Vent

Pressure Measurement

Open tank level

Dash line for closed tank with day leg

VentVent

25 mm

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4. Configuration4.1 OperationsThe transmitter shows the status and the measure on the dot matrix LCD (see fig.10). The span is from -99999 to 999999.The input signal to the transmitter can be related to the output signal in the following ways:- Direct mode = 4÷20mA output- Reverse mode = 20÷4mA output The direct mode is obtained by setting the lower range point with the lowest value of the range (e.g. 0bar o 0m3/h) and by setting the upper range point with the highest value (e.g. 5bar o 1000m3/h). The reverse mode is obtained by setting the lower range point with the highest value of the range (e.g. 5bar o 1000m3/h) and by setting the upper range point with the lowest value (e.g. 0bar o 0m3/h).

To display the temperature values of the sensor (not in flow meters mode) and of the electronic board push the following keys during transmitter operation: = sensor temperature (differential pressure); = electronic board temperature.The unit of measure (°C) is defined in the entry TEMP UNIT in the keyboard menu (follows).In the volumetric flowmeter the pressing of button display the differential pressure.

4.2. Display and Keyboard

Fig. 10 - Display and keyboard

Measure display (6 digits)

Measuring unit

Choice Bargraph / % span

Elect. board T display

LCD Display and keyboard

Sensor T display

Menu entering

Bargraph / % span

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4.3 Keyboard configurationThe electronic transmitters have some configuration functions available via keyboard and LCD display, provided with the instruments themselves.

Press the [MENU] button to enter the password entering dialog; the default password is 0000. Confirm by [OK] to enter the configuration menu.The password is in 4 digits format and spans from 0000 to 9999. If you can’t remember or find the password you set, please contact our service department.

When the display is in numerical entering mode, the cursor will blink. To move the cursor press the button; to raise the value of the digit press the button. Confirm with [OK].

Use the and buttons to show the sequence of the available functions and press [OK] to confirm the selected function. The display will allow to choose from the different functions described in the table below. Press the [OK] button to confirm; use instead the [MENU] button to cancel the modifi-cations and to go back to the standard display.

Function Display name Use Choice span

Zero setting LRV

Measure linked to the zero and to the 4mA

output. The measuring unit is shown in the lower right corner of the display

Between the sensor limits

Full span setting URV

Measure linked to the full span and to the 20mA output. The measuring

unit is shown in the lower right corner of the display

Between the sensor limits

Measuring unit selection

PV UNIT(disabled in volumetric flow meters

mode)

Measuring unit selection from the available ones. Press or to scroll.

Pressure:bar, mbar, Pa, KPa, MPa, mmH2O, mH2O, cmH2O,

Kg/cm2, mmHg, psi, Torr, inHg, Atm, ftH2O, g/cm2, inH2O

Level:m, in, cm, mm

Densityspecific gravity, g/cm3,

kg/m3, g/l

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Keyboard Configuration

Function Display name Use Choice span

Configuration of PV CONFIG PV

Selecting of the display mode associated with

primary variable.

1 - PRESS. = pressure

2 - FLOW = flow meter

Transfer function

XFR FUNC(disabled in volumetric flow meters

mode)

Selecting of current output in linear or square root

mode.

LIN = linear

SQRT = volumetric flowmeter

Fluid density

GMavailable in volumetric flow meters

mode)

Insert the fluid density in Kg/m3 measure unit.

>0[Kg/m3]

Fault configuration ALARM TYPE Fault condition analog

output selection.

NONE = no action21.5mA3.85mA

LAST = last read value

Damping setting DAMP VALUE Insert the signal averaging time constant. 0÷60s

Zero re-setting OFFSET

The transmitter links the actual reference input to

the zero display measure. The transmitter will then

show 0 at display after the confirmation by [OK].

-

4mA output automatic setting

(zero)SET LRV

At button pushing the transmitter will

automatically link the 4mA output to the actual

reference input.

-

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Keyboard Configuration

Function Display name Use Choice span

20mA output automatic setting

(span)SET URV

At button pushing the transmitter will

automatically link the 20mA output to the actual

reference input.

Automatic zero elevation SET ZEROEL

At the button pushing the transmitter performs the

zero elevation, in manner to put to zero the actual

measure. The elevation is applied to the whole span.

-

Analog output test LOOP TEST

It is possible to fix the analog output of the

transmitter to a required mA value.

3,85÷21,5 mA

Analog output calibration CAL 4-20mA

The transmitter fixes the output to 4mA and asks by display to check the value (OK? YES/NO).

Choose NO if the output is incorrect and insert the value read on an external amperometer. Do it again

until necessary. The same procedure for 20mA

follows.

-

Hart®

polling address ADDRESS Hart® polling address modification. 0÷15

Transmitter information INFO

The polling address, the lower sensor limit (LSL),

the upper sensor limit (USL) and the firmware

revision are shown.

-

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Keyboard Configuration

Function Display name Use Choice span

Password setting PASSWORD

Allows to insert a new password

for the transmitter. To be used with care.

0000÷9999

ExpertCommand:Manual zero

elevation

ZERO ELEV.(disabled in volumetric flow meters

mode)

Manual zero elevation insertion.

6 digits, including "–" sign and decimal point

ExpertCommand:Gain setting

SG VALUE Manual inverse gain insertion (specific gravity) 0,1÷10

Factory setting restore RESTORE Select and confirm using

buttons and [OK]. -

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4.4 Remote operations via HART® protocolThe electronic transmitters LD256 are totally comply with the HART® protocol specification Revision 6.0, so they include remote process variable interrogation, parameter setting and diagnostics.The device is a 4÷20mA 2-wire transmitter, with FSK communication. It is possible to read via HART® the following variables: PV: transmitter main measure; SV: % of the span; TV: analog output;

In volumetric flowmeter configuration: TV: differential pressure QV: transmitter temperature.

Please refer to Fig. 12 for the Hart® modem connection on transmitter’s 4÷20 mA loop. In Fig. 11 the multidrop connection type is shown.

Hand-held configuration

(HHT)

HARTserver

HARTmodem

USB, RS232, ...

15 HART transmitters

No 4÷20 mA loopVcc = 24 Vdc

R = 250÷550 Ohm

Fig. 11 - HART® connection multidrop

213.887.5275.200

Hand-held configuration

(HHT)

HARTserver

HARTmodem

USB, RS232, ...

HART transmitters on polling address 0

4÷20 mA loopVcc = 24 Vdc

R = 250÷550 Ohm

Fig. 12 - HART® connection loop 4÷20 mA

4.4.1 MaintenanceTransmitters do not require a maintenance on periodical basis.

Periodically check the general transmitter status, the possible presence of rust or damage on the case or on the measuring diaphragm and the presence of clogging in the process connection.

22 3.887.5275.200

4.4.2 TroubleshootingPlease refer to the following pages scheme for troubleshooting.

In any case contact our service department for help.

Condition Potential source Solution

The transmitter doesn’t turn on

Supply Check the supply voltage to be 12Vdc<Vsupply<40Vdc.

Polarity Check the transmitter connection polarity.

Electrical load Check that the load is less than the maximum allowed.

Measure is uncorrect

Process Accurately verify the compatibility between the process and the connection type.

Sensor drift Apply zero input conditions to the transmitter and use the OFFSET command.

EMC interferenceAccurately verify the possible presence of

electromagnetic interference on the supply line. Check the PE connection.

Erratic analog output

Wrong span limits Use the LRV and URV commando (or SET LRV and SET URV) to correct the output.

Uncalibrated analog output

Use the LOOP TEST command to verify the analog output calibration. If it is not correct,

use the CAL4-20mA command to calibrate the output.

Uncorrect HART® settings

Use the ADDRESS command to verify that the polling address is set to 0.

Analog output <4mA o >20mA

Transmitter in fault mode

Check if the output isn’t out of the allowed span or check the presence of a failure (e1, e2, … on

display).

Wrong fault settings Check the settings using the ALARM TYPE command.

Unstable measure Measuring disturbs Set an input average using the DAMP VALUE command (i.e. 10 seconds).

Impossible to access the menu

Wrong / forgotten password Contact us for help.

233.887.5275.200

5. Spare partsTogether with the request of spare parts it is required to indicate Serial Number of the instrument to control that the correct component will be delivered. Available spare parts are (with its own code and mounting quantity in parenthesis).

Fig. 13 - Housing Fig. 14 - Absolute and relative pressure measuring element LD256

Housing (Fig. 13)(1) Measuring element (see next figures);(2) Plug for housing;(3) Terminal board:(4) Electronic module;(5) Microcontroller;(6) Name plate;(7) Cable gland (2 pcs);(8) Cover gasket;(9) Forward cover with window;(10) Display frontal protection;(11) Rear cover.

Primary Element (Fig. 14)(1) Measuring element.

Spirax-Sarco S.r.l. - Via per Cinisello, 18 - 20834 Nova Milanese (MB) - Tel.: 0362 49 17.1 - Fax: 0362 49 17 307

3.887.5275.200 Issue 1 - 2014.07

REPAIRPlease contact our nearest Branch Office or Agent or directly Spirax-Sarco S.r.l. - Ufficio resiVia per Cinisello, 18 - 20834 Nova Milanese (MB) - Tel.: +39 0362 49 171 - Fax: +39 0362 49 17 307

LOSS OF GUARANTEETotal or partial disregard of above instructions involves loss of any right to guarantee.