User’s Guide Shop online at LDX-3A omega.com e-mail: info@omega.com For latest product manuals: omegamanual.
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1.0: Index Section Title 1.0 Section Title Index . . . . . . . . . . . . . . . . . . . . . . . . . 1 4.6.2 Current Connections . . . . . . . . . . . . . . . . . 12 2.0 Safety Information . . . . . . . . . . . . . . . . 2 4.7 Using an EMC Cable Gland . . . . . . . . . . 13 3.0 Introduction . . . . . . . . . . . . . . . . . . . . . 5 5.0 Setting up the Transducer and LDX-3A . . . 14 3.1 LDX-3A Enhancements . . . . . . . . . . . . 5 5.1 Option Links Explained . . . . . . . . . . . . . 15 4.
2.0: Safety Information Terms in this Manual WARNINGS: WARNING statements identify conditions or practices Do not operate in explosive atmosphere that could result in personal injury or loss of life. To avoid explosion, do not operate this equipment in an explosive atmosphere. CAUTION statements identify conditions or practices Installation Environment that could result in damage to the equipment or other The power supply unit is for indoor use only. It should property.
2.0: Safety Information Service Safety Safety Compliance Statement LDX-3A is designed as Safety Class 2 apparatus with functional ground to comply with IEC 61010-1. The power supply unit is marked as compliant with EN60950-1, but when as part of the LDX-3A assembly and installed by qualified personnel according to these user instructions, then IEC 61010-1 compliance can be achieved.
2.0: Safety Information CAUTION: Electrostatic Discharge This equipment is susceptible to ESD (Electrostatic Discharge) when being installed or adjusted, or whenever the case cover is removed. To prevent ESD related damage, handle the conditioning electronics by its case and do not touch the connector pins. During installation, follow the guidelines below. - Ensure all power supplies are turned off. - If possible, wear an ESD strap connected to ground.
3.0: Introduction The LDX-3A is a development of the original LDX-3A. It is a compact conditioning module powered from an external power supply unit. Adjustable gain and zero controls are provided for use with the complete range of Omega LVDT and half-bridge transducers.* The unit is of robust construction, housed in a die cast metal box providing a substantial degree of mechanical protection. The LDX-3A uses a universal mains input power supply and provides an output of up to ±10V and ±20mA. 3.
4.0: Installation 4.1: Mounting The LDX-3A may be mounted in a variety of ways and in any attitude. Ensure that there is enough space for the cover to be removed to allow for internal adjustments. Space should also be allowed for the transducer connector, EMC glands (if fitted) and cabling. It is recommended that the LDX-3A case be connected to earth or chassis. This earth connection is not a safety earth, but is part of the overall electrical screening scheme.
4.0: Installation (continued) 4.2: Operational Environment This section discusses the type of installation required depending on the electrical environment. 4.2.1: Residential, Commercial and Light Industrial Environments Typically, this will be an office, laboratory or industrial environment where there is no equipment likely to produce high levels of electrical interference, such as welders or machine tools. Connections may be made using twisted, unscreened wire.
4.0: Installation (continued) 4.3: Electrical Connections The LDX-3A requires three connections. 1. Transducer 2. Mains power supply. 3. Output signal, voltage or current. A small hole should be made in the grommet prior to passing the wires through. If a screened cable is to be used, an EMC cable gland is recommended. For best performance in electrically noisy environments, the case of the LDX-3A should be connected to a local earth. This can be achieved via the mounting bracket.
4.0: Installation (continued) 4.4: Connecting the Transducer Transducers fitted with a 5-pin DIN plug are simply screwed into the case mounted socket. Transducers not fitted with a plug should be wired to the plug supplied. For the half-bridge only variant see section 6.0.
4.0: Installation (continued) 4.5: Mains Power Supply The mains adaptor is pre-wired to the LDX-3A. This is a universal power adaptor, so no adjustments are required for mains frequency or voltage. Please review safety statements and installation section. 1.8m lead Gktpodfg ggfdgjs dfofkg f sdreyot Gktpodfg ggfdgjs dfofkg f sdreyot WARNING: Ensure that the local safety precautions are observed for installation of mains equipment.
4.0: Installation (continued) 4.6: Connecting the Signal Out The output signal may be voltage or current. 4.6.1: Voltage Connections Voltage is most easily be monitored using a variety of instrumentation such as voltmeters. Voltage drops along wires contribute to measurement errors, so care must be taken when using long cable lengths (100m for example). High impedance instruments are more prone to interference.
4.0: Installation (continued) 4.6.2: Current Connections Current output requires the use of purposely designed current input instrumentation. Current output is more suitable for transmitting over longer distances because current is not lost due to wiring resistance. Additionally, with a low impedance, a current loop is less likely to pick up noise.
4.0: Installation (continued) 4.7: Using an EMC Cable Gland To ensure the cable screen is properly connected to the LDX-3A case, an EMC cable gland should be used. This is supplied as an extra. The diagrams below assume a single 4-way cable is being used. Remove the grommet and fit the cable gland as shown below. 30 mm 10-15 mm 125 mm Rotate Gland Body to Tighten Screen Case Wall Sealing Ring - Prepare cable as shown.
5.0: Setting up the Transducer and LDX-3A The LDX-3A may be set-up with output signals anywhere within a ±10 Vdc or ±20 mA range. Typical outputs are ±10 Vdc, ±5 Vdc, 0-10 Vdc and 4-20 mA. These procedures apply to voltage and current output. Voltage and current output are available at the same time, although they cannot be individually adjusted. Either voltage or current should be chosen as the calibration reference. All outputs use 0V signal as the signal reference.
5.0: Setting up the Transducer and LDX-3A (continued) 5.1: Option Links - Explained The table below and subsequent diagrams explain the link functions and show the factory setting.
5.0: Setting up the Transducer and LDX-3A (continued) 5.2: Basic Procedure To set-up the LDX-3A, some basic steps should be followed. The following steps describe a typical setting procedure and applies to most applications. Other procedures may be used as appropriate.
5.0: Setting up the Transducer and LDX-3A (continued) 5.2: Basic Procedure STEP 1 - Set-up LDX-3A Links If the transducer characteristics are known, set the frequency and input resistance links as required. If the transducer characteristics are not known, the standard link settings should be used. If your transducer is known to be outside of the standard sensitivity range, the X2 or DIV2 links will have to be used. See section 5.3. STEP 2 - Align LDX-3A Null and Transducer Null Null the LDX-3A. 1.
5.0: Setting up the Transducer and LDX-3A (continued) 5.2: Basic Procedure STEP 3 - Setting Bi-Polar Full-scale Output 1. Move the transducer to the position where maximum LDX-3A output is required. 2. If the polarity of the output is wrong, move the Polarity (FR) links to the R position (see link diagram). Normal Output Polarity Reverse Output Polarity 10K 2K -¦R¦ |F| -DIV 2 X2 X4 10K 2K -¦R¦ |F| -DIV 2 X2 X4 3. Move the RANGE link between 1 and 6 until the LDX-3A output is near the required value. 4.
5.0: Setting up the Transducer and LDX-3A (continued) 5.2: Basic Procedure STEP 4 - Setting Uni-polar Full-Scale Output (adding an offset) 1. Move the transducer to the null position. LDX-3A output will be 0V or 0mA. 2. Apply offset using the +VE, -VE, 5V and 10V links and then adjust the Fine Offset control to set the offset precisely. 3. Perform final checks, step 5. Example: 0-10V is required for a ±1mm transducer.
5.0: Setting up the Transducer and LDX-3A (continued) 5.3: Transducer Sensitivity and the X2, X4, DIV2 Link The LDX-3A compensates for changes in primary signal amplitude by producing an internal error signal that is the ratio between the primary and secondary signals. If the transducer output signal is too high or too low, errors may occur that can degrade the performance of the LDX-3A / transducer combination. For these transducers, the X2, X4 or DIV2 input gain link must be used.
6.0: Half-Bridge only Variant This is a Half-Bridge optimised variant of the standard product. The excitation frequency is higher (see specification) and the transducer input connector is wired to accept half-bridge transducers with standard connections. 6.1: Connecting the transducer The 5-pin DIN plug is screwed into the case mounted socket. Transducers not fitted with a plug should be wired to the plug supplied. LVDT transducers cannot be connected to this input.
7.0: Specifications 7.1: Electrical Specifications are for the LDX-3A only. Effects due to transducers are not included. Output is set to ±10Vdc into a 1kΩ load, unless specified differently. FRO means ‘Full Range Output’. Parameter Power Supply Mains Voltage AC Input Frequency AC Input Current Value 90 to 264 Vac 47 to 86 Hz 0.25 A (120 Vac), 0.1 A (250 Vac) Transducer Excitation Energising Voltage Energising Frequency 3Vrms nominal 2.
7.0: Specifications (continued) 7.1: Electrical Parameter Signal Output Output Voltage Range Output Residual Noise Output Current Parameter Comments Up to ±10Vdc into 1kΩ min <1 mV rms Up to ±20mA into 150Ω load see notes 3 and 4 Output Offset ±5Vdc (approx 10mA) fixed ±10Vdc (approx 10mA) fixed ±2.8Vdc (approx 5.
7.0: Specifications (continued) 7.2: Mechanical and Connections Parameter Value Transducer Power Supply Cable Length Mains Connector Output Signal Enclosure Size Weight Material 5-pin circular DIN 1.8m maximum, fixed length IEC320 C14 Internal terminal block 120 x 65 x 40 mm 300g approximately Die-cast Zinc Alloy (painted) Power Supply 65 x 49 x 33 mm 120g approximately Size Weight Comments Adaptor to LDX-3A case C13 Mains lead supplied as required excluding connectors (See note 10) 7.
7.0: Specifications (continued) 7.4: Notes 1. Primary voltage absolute value and drift are not specified. The LDX-3A uses ratiometric techniques to compensate for primary voltage drift. 2. The way in which the LDX-3A functions means a special configuration must be used for transducers outside of the standard range. This is selectable by links. The majority of Omega LVDT transducers are within the standard range. The user manual provides details of the selection criteria. 3.
7.0: Specifications (continued) 7.4: Notes 8. The power supply unit alone is certified as described. When used as part of the LDX-3A and installed as described in the user manual, then compliance with IEC 61010-1 can be achieved. 9. The LDX-3A itself has a 0 - 60°C specification. The power supply will function over a wider temperature range, but the safety approval is only valid for 0 - 50°C. 10. The LDX-3A enclosure is smaller than the old model. This means that it will fit into all existing applications.
WARRANTY/DISCLAIMER RETURN REQUESTS/INQUIRIES OMEGA ENGINEERING, INC. warrants this unit to be free of defects in materials and workmanship for a period of 13 months from date of purchase. OMEGA’s Warranty adds an additional one (1) month grace period to the normal one (1) year product warranty to cover handling and shipping time. This ensures that OMEGA’s customers receive maximum coverage on each product. Direct all warranty and repair requests/inquiries to the OMEGA Customer Service Department.
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