MX2534
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Datasheet MX2534 Case Expansion Transducer System Overview The MX2534 Case Expansion Transducer System consists of a loop-powered DC Linear Variable Differential Transducer (LVDT) mounted in an appropriate enclosure. The unit produces a 4-20mA signal that is directly proportional to the position of the LVDT plunger rod. It can be externally powered, or when used with a SETPOINT Machinery Protection System UMM module, the UMM itself provides all necessary power. The NEMA 4 enclosure provides physical protection of the LVDT and its cable connection. The LVDT itself is a hermetically sealed unit rated to IP68. It is designed for use in the moderately high steam environments and ambient temperatures found adjacent to an HP turbine case. The MX2534 is designed specifically to measure thermal expansion of steam turbine cases relative to their foundation. The case expansion measurement is typically required as part of a suite of supervisory measurements on steam turbines in power generation service. Refer to page 2 of this datasheet for additional details on the case expansion measurement. Connection to the MX2534 is made by means of the MX2531 cable assembly*, available in lengths up to 100 feet (30 m). One end has an integral 6-pin MIL connector that mates directly to the LVDT; the other end is provided with flying leads, allowing transition to longer field wiring runs in a junction box. The MX2534 is available with or without a spring return mechanism. When used without a spring return, the LVDT plunger rod is rigidly attached to a bracket on the turbine’s sliding foot, such that the plunger is pushed or pulled by the bracket as the turbine expands or contracts. When used with a spring return, the plunger rod is supplied with a rounded tip and merely rests against the sliding foot’s bracket. As the turbine expands, the plunger is compressed. As the turbine contracts, the internal spring mechanism pushes the plunger outward such that it is in constant contact with the bracket. The selection of either version allows flexibility in retrofit situations, but the spring return version is more tolerant of side-to-side and up-and-down movement that would otherwise strain the LVDT with a rigid bracket attachment scheme. Because the spring mechanism is hermetically sealed inside the LVDT body, it is less prone to corrosion and wear than older designs with external spring mechanisms. However, the spring return must be specified at time of ordering. It is not an external assembly that can be retrofit to non-spring LVDTs. * NOTE: In instances where a continuous run will be used between the LVDT and its associated monitoring system, the MX2531 cable assembly is not required. One (1) mating connector (p/n 99501-026) is supplied loose with each MX2534 and does not need to be ordered separately. This allows the installer to attach their own field wiring directly to the mating connector pins.

Applications A steam turbine undergoes thermal expansion as its case heats during steam admission. Likewise, it undergoes contraction as its case cools during steam reduction. The extremely large casing sizes and extremely high steam temperatures of turbines used in electric power generation service can easily result in up to two inches (50 mm) of axial growth. To accommodate this growth, the turbine’s case (shell) is rigidly attached to a foundation at one end, but allowed to float at the other end on special sliding feet. If one or both feet become stuck, the casing cannot expand or...

Max. Loop Resistance vs. Supply Voltage Unless otherwise noted, all specifications are at 25° C and subject to change without notice. Electrical Loop Supply Voltage Loop Resistance Output Output Noise and Ripple Output Slope Scale Factor (SF) 10 to 28 Vdc Min: 50Ω Max: Refer to figure at right 4-20 mA ≤ 10 μA rms 4mA = core fully extended 20mA = core fully inserted 1” Version 2” Version 16 mA/in 8 mA/in (0.63 mA/mm) (0.315 mA/ mm) Thermal Coefficient of SF Frequency Response (-3dB) Linearity Error Repeatability Error Hysteresis Error Nominal Range Ordering Information MX2534 Case Expansion...

MX2531 DC LVDT Cable Assembly This cable assembly is used for runs up to 100’ between the LVDT and a junction box or monitoring system. For longer lengths, field wiring can be attached directly to the loose connector (99510-026) that ships with the MX2534. Alternatively, the pre-assembled cable can be used between the LVDT and a junction box, and field wiring can be used from the junction box to the monitoring system. The MX2531 cable assembly is available with or without armor. Armor cannot be trimmed to length in field and extends to within 2’ of cable end. Cable length, in ft (increments...

Outline Diagrams NOTES: (UNLESS SPECIFIED OTHERWISE) CASE EXPANSION TRANSDUCER W/O SPRING RETURN OPTION (BB=00) NOTES. (UNLESS SPECIFIED OTHERWISE) 3. 1/2" CONDUIT FITTING, SUPPLIED BUT NOT INSTALLED 5 DIMENSION 'A', FULLY EXTENDED POSITION (REFER TO TABLE 1) 6. LVDT CLAMPS, 2 PLCS Datasheet - MX2534 Case Expansion Transducer System

Cable Length (AAA) Optional Cable Armor (BB=01) Shrink Tubing, Polyolefin (Black), 1” long BELDEN #8786 or equivalent SOURIAU #851 06 AC 106 S 50 or equivalent FUNCTION NC NC NC NC Loop + Loop Shield * Connector terminal assignments on SETPOINT Universal Monitoring Module (UMM). The UMM provides all necessary power for the MX2534; external loop power is not required. Metrix Instrument Company 8824 Fallbrook Drive Houston, TX 77064 USA (281) 940-1802 www.metrixvibration.com info@metrixvibration.com Trademarks used herein are the property of their respective owners. Data and specifications...