Emerson A6500‑LC LVDT Converter
1. Product Overview
The Emerson A6500‑LC is a single‑channel LVDT signal conversion module designed for the Emerson AMS 6500 ATG turbine protection system. Developed for inductive half‑bridge sensors and LVDT displacement transducers, it supplies standard excitation voltage to sensors and converts displacement‑proportional sensing signals into standardized voltage outputs compatible with the A6500‑UM universal measurement card, enabling matched signal transmission between field displacement sensors and system monitoring units.
Built for standard DIN‑rail mounting with compact dimensions, the A6500‑LC integrates directly within the AMS 6500 ATG rack system. It is widely deployed for shaft displacement and differential expansion monitoring on rotating machinery such as steam turbines and compressors. Equipped with on‑board calibration push‑buttons and channel status LED indicators, it simplifies on‑site commissioning and fault diagnosis. Fully compatible with the complete PR93XX displacement sensor series, it supports multiple measurement ranges from ±12 mm up to ±200 mm. The A6500‑LC is the dedicated native LVDT signal conversion unit for the AMS 6500 system.
Download of relevant files
Emerson A6500-LC operating Manual.pdf
2. Core Technical Specifications
2.1 Measurement Performance
| Item | Specifications |
|---|---|
| Measurement Ranges (matched sensors) | ±12 mm/24 mm (PR9350/01), ±25 mm/50 mm (PR9350/02), ±50 mm/100 mm (PR9350/04), ±75 mm/150 mm (PR9350/06), ±100 mm/200 mm (PR9350/08), ±150 mm/300 mm (PR9340/12), ±20 mm/40 mm (PR9314/41) |
| Output Voltage Swing | Symmetric around 10 V; 3.2 V‑12.2 V depending on sensor model |
| Temperature Drift | Typ. ±5.0 % for PR9350/01; typ. ±2.5 % for PR9350/02 ~ PR9340/12 |
| Measurement Accuracy | Full‑scale linear deviation ＜±2 %; replacement error for identical A6500‑LC ＜1 % |
| Signal Noise (Peak‑Peak) | ＜10 mV |
| Output Internal Resistance | Approx. 100 Ω |
| Power‑on Start‑up Time | Approx. 200 ms |
| Frequency Bandwidth (-3 dB) | 0‑10 Hz |
2.2 Signal Output Parameters
- Standard output voltage range: +2 V ~ +18 V, built‑in short‑circuit protection
- Limit output under 24 V supply: +1.1 V ~ +23.3 V
2.3 Electrical Supply
- DC supply voltage: 22.5 V ~ 32 V
- Operating current: ＜30 mA
- Output variation vs supply fluctuation: ＜0.1 % / V
- Over‑voltage protection limit: 60 V; use SELV/PELV power source
- Sensor excitation: 2.2 Vrms, 5 kHz AC
2.4 Environmental & Mechanical Data
- Ingress protection: IP20
- Storage temperature: -35 ℃ ~ +85 ℃
- Relative humidity: 5 %‑95 %, non‑condensing
- Vibration compliance: EN 60068‑2‑6; Shock: 15 g (EN 60068‑2‑27)
- Maximum sensor cable length: 30 m
- Housing material: PA6.6 Nylon
- Screw terminals: suitable for 1.5 mm² ferruled wires
- Dimensions: W 20 mm × H 79.5 mm × L 69.5 mm
Net weight: 65 g; total packed weight: 195 g
3. Key Features & Benefits
- Dedicated signal conversion: Resolves signal incompatibility between LVDT / half‑bridge inductive sensors and A6500‑UM universal measurement card. No additional isolation modules required, simplifies system wiring.
- Multi‑range sensor compatibility: One A6500‑LC supports 7 mainstream PR93XX displacement sensors, covering measurement ranges from small differential expansion to large‑stroke shaft displacement for high module versatility.
- Low replacement error: Measurement deviation remains within 1 % after module swap. Full‑system recalibration is often unnecessary, shortening unit downtime during maintenance.
- Robust hardware protection: Output short‑circuit protection, 60 V over‑voltage protection and EMC interference resistance. Stable operation inside high‑EMI industrial cabinets; supports sensor cable runs up to 30 m without signal attenuation.
- Convenient on‑site calibration & diagnostics: Front‑panel ZERO and CAL push‑buttons plus CH‑OK status LED. Zero adjustment and channel fault detection can be performed without host software.
- Low‑power compact design: Operating current below 30 mA; narrow 20 mm DIN‑rail form‑factor allows dense multi‑module installation and saves cabinet space.
4. Hardware Characteristics
- Mounting: Tool‑free clip‑on standard DIN‑rail mounting. Optional BOX030 wall‑mount housing holding up to six A6500‑LC units.
- Terminals: Top‑and‑bottom screw terminals with clear labeling for power supply, sensor input and system signal output to prevent mis‑wiring.
- Operator panel: Multi‑color LED indicators; CH‑OK green LED = channel healthy; CAL button for linear calibration; ZERO button for displacement zero reset.
- Housing: Flame‑retardant PA6.6 engineering plastic, temperature‑resistant and dust‑resistant, suitable for dusty high‑temperature cabinets in power plants and chemical sites.
- Standard interfaces: Powered directly from AMS 6500 ATG rack 24 V DC bus; output connects directly to A6500‑UM measurement card inputs with negligible signal loss.
- Environmental robustness: Passed industrial vibration, shock and thermal cycling testing. Measurement drift‑free under high‑vibration conditions inside turbine and compressor buildings.
5. Application Areas
- Thermal / Gas Turbines: Continuous on‑line monitoring of rotor differential expansion, axial displacement and valve stem travel; unit trip protection via AMS 6500 ATG.
- Chemical Process Compressors: Shaft displacement and piston stroke monitoring for reciprocating and centrifugal compressors; interlock trip signals upon threshold violation.
- Oil & Gas Boosting Units: Rotor displacement and valve actuator stroke monitoring for pipeline turbo‑compressors.
- Hydro‑Turbines: Wicket‑gate opening and main‑shaft axial thrust monitoring.
- Large ID / FD Fans: Rotor axial displacement protection monitoring.
Metallurgical Turbomachinery: Differential expansion measurement for furnace turbo‑expanders.
6. Operating Principle
The A6500‑LC integrates an internal 5 kHz, 2.2 Vrms AC excitation source delivering stable alternating drive voltage to external LVDT / half‑bridge inductive sensors. Sensors generate amplitude‑modulated AC signals whose magnitude varies linearly with physical displacement.
Internal signal conditioning circuitry rectifies, filters and amplifies the AC input and converts it into a standard DC voltage signal within 0‑18 V range. This conditioned voltage is transmitted to the A6500‑UM universal measurement card for acquisition and processing. Data is uploaded to the AMS 6500 ATG rack for displacement value display, alarm threshold evaluation and machinery protection interlock outputs.
The front‑panel ZERO button corrects mechanical installation zero offset. The CAL button triggers built‑in linear calibration routines to compensate sensor‑module matching errors. The CH‑OK LED monitors sensor‑cable open‑circuit and short‑circuit faults; it extinguishes upon wiring failure for rapid loop diagnostics.
7. Compatible Products
7.1 System Boards
- A6500‑UM: Universal measurement card, dual‑channel sensing acquisition, exclusive receiver for A6500‑LC converted voltage signals.
- A6500‑SR / A6500‑RR: 19‑inch system racks providing 24 V power bus and internal signal bus for A6500‑LC and A6500‑UM.
- A6500‑CC: System communication card, collects displacement data from A6500‑UM, outputs Modbus TCP / OPC UA.
- A6500‑TP: Temperature process card for multi‑parameter unit monitoring together with displacement data from A6500‑LC.
- A6500‑RC: System relay card receiving over‑range displacement signals and providing dry‑contact interlock outputs.
7.2 Compatible LVDT / Half‑Bridge Displacement Sensors
PR9350/01, PR9350/02, PR9350/04, PR9350/06, PR9350/08, PR9340/12, PR9314/41
7.3 Mounting Accessories
- BOX030: Wall‑mount enclosure, capacity up to six A6500‑LC modules.
8. AMS A6500 Series Recommended Models
- A6500‑LC LVDT Converter
- A6500‑UM Universal Measurement Card
- A6500‑CC System Communication Card
- A6500‑TP Temperature Process Card
- A6500‑RC System Relay Card
- A6500‑SR Standard System Rack
- A6500‑RR Redundant System Rack
- A6220 Shaft Eccentricity Monitoring Card
- A6140 Vibration Monitoring Module
- A6312 Dual‑Channel Protection Monitoring Card
- A6620 Speed Monitoring Card
- A6824 Vibration Output Module
- A6500‑FR Front‑End Terminal Rack
- A6125 Low‑Frequency Bearing Monitoring Card
9. FAQ
Q1: Must A6500‑LC be used with A6500‑UM?
A1: Yes. The dedicated output signal of A6500‑LC only interfaces with the A6500‑UM universal measurement card. It cannot connect directly to third‑party PLC or vibration acquisition hardware; they form a fixed matched set.
Q2: Can one A6500‑LC connect two PR9350 sensors simultaneously?
A2: No. A6500‑LC is a single‑channel converter supporting one‑to‑one connection with one LVDT / half‑bridge sensor. Multiple measurement channels require multiple A6500‑LC units.
Q3: Is full‑loop recalibration needed after replacing A6500‑LC?
A3: Under normal operating conditions full‑system recalibration is not required. Specified replacement error for identical modules is below 1 %. Only execute ZERO push‑button zero reset. Perform full CAL linear calibration for high‑precision metrology applications.
Q4: What is the maximum permissible PR93XX sensor cable length?
A4: The specified maximum cable length is 30 m. Longer runs cause signal attenuation and increased thermal drift. Signal‑isolating preamplifiers are required for longer distances.
Q5: What is the allowable supply voltage fluctuation range?
A5: Valid DC supply range: 22.5 V‑32 V. Minor variations on a 24 V nominal system barely affect measurement accuracy, output error below 0.1 % per volt change.
Q6: Does purchasing A6500‑LC include BOX030 wall‑mount housing?
A6: Standard A6500‑LC unit does not include BOX030. BOX030 is an optional accessory ordered separately for installations without DIN‑rail mounting possibility.
Q7: Can A6500‑LC perform high‑frequency dynamic displacement measurements up to 100 Hz?
A7: No. Module bandwidth is limited to 0‑10 Hz. It is intended only for slow‑changing machinery displacement such as differential expansion, axial shaft displacement and valve stem travel. High‑frequency vibration displacement requires eddy‑current sensors directly acquired by A6500‑UM.
Q8: Does A6500‑LC carry explosion‑proof certification for installation in hazardous areas?
A8: A6500‑LC is IP20 rated without Ex certification. When deployed inside explosion‑proof cabinets it must be used with certified galvanic isolators / safety barriers. Do not mount directly within Zone 1 or Zone 2 hazardous locations.
Tags: Emerson A6500‑LC, AMS 6500 ATG, LVDT signal converter, PR93XX displacement sensor, turbine protection, compressor monitoring, differential expansion measurement, shaft position monitoring
3005319639