LTU 701

TechnicalSpecification

Table of Contents

LTU 701 Submersible Level Sensor..................................................................................................... 2Product................................................................................................................................................. 2Features................................................................................................................................................ 2Technical features............................................................................................................................... 2Approvals and standards................................................................................................................... 2Safety data, Ex......................................................................................................................................3Dimensions...........................................................................................................................................3Materials............................................................................................................................................... 3Power supply........................................................................................................................................4Mounting.............................................................................................................................................. 4Standard configuration at delivery....................................................................................................4Connection/Installation...................................................................................................................... 4LTU 701 standard measuring ranges................................................................................................5Important notes on intrinsic safe design and lightning protection...............................................6Important notes on the physical properties of LTU 701.................................................................6

Table of Contents

LTU 701 Technical Specification 1

LTU 701 Submersible Level SensorProduct

The Flygt Level Transmitting Unit, LTU 701 is a HART-programmable level sensor, intendedfor measuring a liquid level.

LTU 701 is specifically engineered to withstand the harsh environmental conditionstypically encountered by Flygt pumps: sewage, slurry and viscous liquids as well as seawater; the piezo resistive pressure sensor comes with a corrosion resistant Hastelloy® Cmeasuring diaphragm.

The output is a standard 4–20 mA direct current, proportional to the measured level.Measuring ranges are pre-set at delivery, but may be adjusted with a HART modem and adedicated PC program (e.g. 830062).

LTU 701 is well adapted to the prevalent control systems on the market including the Flygtcontrollers of the APP, FGC and ATU-ranges. It is approved for Ex-hazardous applicationsand is also fitted with overvoltage protection. It is recommended to fit an extra surgearrester (e.g. 839505) in thunderstorm prone regions.

Features• High level of accuracy, repeatability and long-time stability• Broad temperature operating range (-20° C – 80° C)• Resistance to grime and deposits• Resistance to over-pressure (measuring range x 3)• Wearability and high resistance to chemicals (pH 4–12)

Technical featuresPower supply: 9–48 V DC, 2 wire system

Output signal: 4–20 mA (max 22.5 mA)

Temperature in medium: -20 °C – 80 ° C

Inaccuracy, incl. non-linearity, hysteresis andrepeatability:

≤ 0.1%

Long term instability: < 0.1% FS/ 6 months

Thermal drift: < 0.015% FS/ 10° C

Fully programmable via HART modem

Approvals and standardsEMC directive 2004/108/EC: EN61 326-1, EN61 326-2

EN61 326-3

Pressure Equipment Device (PED) directive 97/23/EG: APED1999/AFS1999:4

ATEX 94/9/EC: CENELEC EN60079–0EN60078–11 (2007)

CSA Std C22.2 No 0–10; No 142–M1987 (R 2004); No 157–92 (R2006)

LTU 701 Submersible Level Sensor

2 LTU 701 Technical Specification

UL Std 60079–0 (5th Ed); Std 60079–11 (5th Ed)

NEMKO 07ATEX1118 Ex ia IIC T4CL I, Div 1, Grps ABCD; Type 6P; T4, Ta:-20 to +80 CCL I, Zone 0: Ex ia IIC; IP68AEx ia IICUi=28V; Ii=95mA; Pi=0,7W; Ci=48nF; Li=75uHMade in Sweden for Xylem Water Solutions AB byPondus Instruments AB, Stockholm. MC #255906

Safety data, ExMaximum input voltage, Ui: 28 V

Maximum input current, Ii: 95 mA

Maximum input power, Pi: 0.7 W

Maximum internal capacitance, Ci: 48 nF

Maximum internal inductance Li: 75 uH

WARNING:Only EX-approved products can be used in hazardous areas.The power supply must have a linear resistive output characteristic.The transmitter shall not be subjected to an explosive atmosphere with pressureexceeding 1.1 bar.Installations in EX-applications must be done in accordance with local rules andregulations.Personnel must know about the risks of electric current, and the chemical and physicalcharacteristics of the gas or vapour present in hazardous areas.Intrincically safe circuits are required for the automatic control system. - Use a EX-safetybarrier (e.g. Prod. no. 843055).

DimensionsSensor dimensions Ø 31 mm (largest measure) x 250 mm

Cable dimensionsLine wire area

0.50 mm2

Weight 0.5 kg + 0.04 kg/m

MaterialsWet side parts:

Sensor body Acidproof, stainless steel, SIS2353

Ingress protection IP68 (120 m H2O)

Measuring diaphragm Hastelloy® C

Cable Polyurethane, vented

LTU 701 Submersible Level Sensor

LTU 701 Technical Specification 3

Power supplySensor main supply 9–48 V DC, two-wire system

MountingSubmersible, hanging free from the cable with dedicated suspension attachment. Notpositions dependent.

Standard configuration at deliveryMeasuring range: 4–20 mA, according to part number

Damping: 1 s

Output function: linear

Alarm: off

Made for Xylem by Pondus Instruments, Sweden

Connection/InstallationConnection

13 2

A

Wiring

1 White + VE (9–48 V DC)

2 Brown - VE (0 V DC)

3 Copper wire (shield) P/E connection (ground)

NOTICE:Polarization should not be reversed, though the sensor is fully protected against incorrectpolarization.

Parts

A Membrane vent. Prevents moisture from entering reference pipe - DO NOT CUT OR REMOVE!

AccessoriesPart Part number

EX-barrier 843055

Junction box, including surge arrester and HART resistor 839505

HART modem, including USB connection with clips, 470 W resistor and PCsoftware CD

830062

LTU 701 Submersible Level Sensor

4 LTU 701 Technical Specification

Figure 1: 830062 Figure 2: 899505

Installation

NOTICE:The sensors (part no. 837578, 837579, 838201, 838202, 838203 and 838204 - See tableon next page) all have the same pressure sensor (range 0–20 m) and can be calibratedfrom 0 to 20 m, by means of a HART modem.

Exception:The 0–3,5 m sensor (part no. 838200) can only be calibrated within its range.

LTU 701 standard measuring rangesMeasure range, m H2O (bar) Max overload, m H2O (bar) Cable length, m Intrinsic safety Part no.

0–3.5 (0–0.35) 25 (2.5) 15

II 1G

838200

LTU 701 Submersible Level Sensor

LTU 701 Technical Specification 5

0–5.0 (0–0.50) 60 (6.0) 20

II 1G

838201

0–5.0 (0–0.50) 60 (6.0) 50

II 1G

838202

0–10 (0–1.0) 60 (6.0) 25

II 1G

838203

0–20 (0–2.0) 60 (6.0) 35

II 1G

838204

0–5.0 (0–0.50) 60 (6.0) 20 837578

0–10 (0–1.0) 60 (6.0) 25 837579

Important notes on intrinsic safe design and lightning protectionIntrinsic safe design and lightning protection cannot be optimized simultaneouslybecause:

II 1G

The Intrinsic safe design (Ex ia) requirement demands that the unit canwithstand at least 500 V DC insulation test voltage between supply (+ or – ) andground, without short circuiting.

Lightning protection, on the other hand must connect incoming surge voltage atthe lowest possible level (above the max. supply 48V DC) to ground.

For the above reasons, the two LTU 701-models with built in lightning protection (part no.837578 and 837579) are not EX-approved.

Important notes on the physical properties of LTU 701The piezo resistive sensor is connected to the measured media by means of a diaphragm.Pressure acting directly on the diaphragm is propagated to the sensor through a pressureintermediate oil, completely filling the volume between diaphragm and sensor.The Hastelloy® C diaphragm is embossed to the surface underneath it duringmanufacturing, making it largely insensitive to particles and physical contact.The atmospheric pressure on the reverse side of the sensor (used for reference) isaccessed through a capillary tube embedded in the probe cable.

LTU 701 Submersible Level Sensor

6 LTU 701 Technical Specification

The diaphragm transportation protection cap can be safely removed, but it is advisable toleave it in place when sharp, protruding objects may be encountered in the pump wellduring operation. The cap is designed so that it should not interfere with measurementseven in typically "greasy" applications, where clogging would normally be a concern.

NOTICE:Caution! Low pH in media (a.k.a."free hydrogen (gas)") i.e. acidic conditions, pH<4, mayaffect the life span of LTU 701 adversely. If you are uncertain, please contact Xylem foradvice.

LTU 701 Submersible Level Sensor

LTU 701 Technical Specification 7

Xylem |’zīləm|

1) The tissue in plants that brings water upward from the roots2) A leading global water technology company

We're 12,000 people unified in a common purpose: creatinginnovative solutions to meet our world's water needs. Developing newtechnologies that will improve the way water is used, conserved, andre-used in the future is central to our work. We move, treat, analyze,and return water to the environment, and we help people use waterefficiently, in their homes, buildings, factories and farms. In more than150 countries, we have strong, long-standing relationships withcustomers who know us for our powerful combination of leadingproduct brands and applications expertise, backed by a legacy ofinnovation.

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Xylem Water Solutions ABGesällvägen 33174 87 SundbybergSwedenTel. +46-8-475 60 00Fax +46-8-475 69 00http://tpi.xyleminc.com

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The original instruction is in English. All non-Englishinstructions are translations of the original instruction.

© 2011 Xylem Inc

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