Description
Technical Parameters
| Parameter | Specification |
|---|---|
| Analog Inputs | 8 differential, thermocouple-dedicated |
| Input Types | TC (J,K,T,E,R,S,B,N) – full ITS-90 |
| Analog Outputs | None (input-only) |
| ADC Resolution | 20-bit sigma-delta (effective: 18 bits) |
| Sampling Rate | 10-1000 Hz per channel (user-selectable) |
| Accuracy | ±0.03% FS (25°C); ±0.08% (-40°C to +85°C) |
| CJC Accuracy | ±0.2°C (integrated, four sensors) |
| Isolation | 2500V RMS (field-to-backplane) |
| CMRR | >110 dB at 50/60 Hz |
| Operating Temp | -40°C to +85°C |
| Power Supply | +5V @ 1.3A; +15V @ 0.55A (VME backplane) |
| Power Dissipation | 10W max |
| Diagnostics | Open/short detection, out-of-range, rate-of-change, CJC health, internal temp, supply telemetry, advanced predictive health monitoring |
| Form Factor | 6U VME (single-slot) |
| Firmware | Field-upgradeable via JTAG and USB |
| Conformal Coating | Standard |
| MTBF | >300,000 hours |
Advantages and Key Features
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Thermocouple-Dedicated Design – Optimized exclusively for TC signals; no unnecessary circuitry, improving reliability and CJC accuracy.
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20-Bit ADC – Industry-leading resolution and accuracy for thermocouple measurement.
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Superior CJC Accuracy – ±0.2°C, the best in the Speedtronic lineup.
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Highest Isolation – 2500V, matching the best universal modules.
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Fastest Sampling – Up to 1000 Hz, equal to HMAC1H1F.
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Advanced Diagnostics – Predictive health monitoring algorithms for early fault detection.
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Field-Upgradeable Firmware – JTAG and USB ports for easy updates.
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Conformal Coating Standard – Built-in protection for harsh environments.
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Hot-Swap Capable – IEEE 1101.11 compliant.
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ITS-90 Linearization – Full standard tables including N-type.
Application Fields
| Industry | Applications |
|---|---|
| Power Generation (Gas Turbines) | GE Frame 7HA/9HA/6F – advanced EGT monitoring, combustion dynamics, TIT control |
| Power Generation (Steam Turbines) | GE D-20 – high-pressure steam temperature, bearing vibration monitoring |
| Combined Cycle | Advanced HRSG control – fast-response superheater/reheater temperature |
| Oil & Gas | LNG compressor stations – high-speed surge detection, turbine exhaust |
| Marine | LM2500/LM6000 naval – high-vibration thrust bearing and exhaust monitoring |
| Renewables | CSP with turbine backup – HTF temperature control |
Comparison with HMPG Series (GE Internal)
| Feature | DS3800HMPJ | DS3800HMPG1G1D | DS3800HMPG | DS3800HMAC1H1F |
|---|---|---|---|---|
| ADC Resolution | 20-bit (18 eff.) | 18-bit (16.5 eff.) | 18-bit (16.5 eff.) | 18-bit (16.8 eff.) |
| Accuracy | ±0.03% | ±0.05% | ±0.05% | ±0.04% |
| CJC Accuracy | ±0.2°C | ±0.3°C | ±0.3°C | ±0.4°C |
| Max Sampling | 1000 Hz | 500 Hz | 500 Hz | 1000 Hz |
| Isolation | 2500V | 2000V | 2000V | 2500V |
| Firmware Upgrade | Yes (JTAG+USB) | Yes (JTAG) | Yes (JTAG) | Yes |
| Conformal Coating | Standard | Optional | Optional | Standard |
| Diagnostics | Predictive health | Advanced | Advanced | Advanced+ |
| MTBF | 300k hrs | 245k hrs | 240k hrs | 280k hrs |
Competitor Comparison:
| Feature | DS3800HMPJ | Siemens 6ES7531-7KF00 | ABB AI830 | Rockwell 1756-IF8I |
|---|---|---|---|---|
| Platform | GE VME Speedtronic | S7-1500 | ABB 800xA | ControlLogix |
| Inputs | 8 TC-only | 8 universal | 16 universal | 8 isolated |
| CJC Accuracy | ±0.2°C | ±0.5°C (external) | ±1.0°C | N/A |
| Isolation | 2500V | 500V (group) | 2500V | 2500V |
| Sampling | 1000 Hz | 100 Hz | 100 Hz | 100 Hz |
| VME Native | Yes | No | No | No |
| Hot-Swap | Yes | No | Yes | Yes |
| Conformal Coating | Standard | Optional | Optional | Optional |
Key Differentiator: The General Electric DS3800HMPJ is the absolute pinnacle of TC-dedicated input modules in the Speedtronic lineup, offering 20-bit resolution, 1000 Hz sampling, ±0.2°C CJC accuracy, 2500V isolation, and predictive health diagnostics—all with native VME compatibility that no competitor can match.
Selection Recommendations
| Scenario | Recommendation |
|---|---|
| New Mark V/VI system with EGT monitoring | DS3800HMPJ is the definitive choice—best TC-dedicated performance available. |
| Upgrading from HMPG or HMPF series | Significant upgrade: 20-bit ADC, 1000Hz, 2500V isolation, predictive diagnostics, standard conformal coating. Pin-compatible; verify Mark V firmware V5.05+. |
| Need outputs as well | Use DS3800HMAC1H1F (universal with outputs) — still excellent but not TC-dedicated. |
| Need highest accuracy overall | DS3800HMPJ offers ±0.03% accuracy, the best in the Speedtronic lineup. |
| Need N-type thermocouple support | DS3800HMPJ fully supports N-type. |
| Triple-redundant | Use three identical HMPJ modules. Do not mix HMPJ with HMPG/HMPF in TMR sets. |
| Non-GE retrofit | Do not use – strictly for VME Speedtronic. |
| Spare stock | Stock one spare per three active units. Lead times: 8-12 weeks. |
| Harsh environment | Conformal coating is standard on HMPJ—no need to specify separately. |
Critical Precautions
Pre-Installation
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Authenticate module – Check GE hologram, serial number traceability, NIST calibration certificate.
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Verify firmware – Read via JTAG or USB; confirm Mark V compatibility (V5.05+ recommended).
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Inspect connectors – Check P1/P2 for bent pins or corrosion.
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Verify conformal coating – Standard on HMPJ; check for uniform coverage.
Installation
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ESD protection – Wear grounded wrist strap; handle by edges only.
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Backplane voltage – Verify +5V (±2%), +15V (±1.5%), -15V (±1.5%) before insertion.
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Insertion – Align guides, apply even pressure, tighten retaining screws to 0.4-0.6 Nm. Never force.
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Power-on – Insert before applying backplane power.
Field Wiring (Critical for TC Accuracy)
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Cable – Must use thermocouple-grade extension wire matching TC type (e.g., Type K extension for Type K). Copper wire introduces significant measurement errors.
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Shielding – Belden 8760 or equivalent shielded twisted-pair. Connect shield to module shield terminal; ground only at module end (not both ends).
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Separation – 30cm from AC power; 60cm from VFD cables; cross at 90° if unavoidable.
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Torque – 0.5-0.6 Nm (4.4-5.3 lb-in); strip length 7-8mm.
Firmware & Configuration
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Field-upgradeable – Use JTAG or USB programmer; follow GE procedure carefully.
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Channel config – Use Mark V Toolbox to select TC type for each channel.
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Open-circuit config – Select upscale or downscale drive for burnout detection (typically upscale for EGT).
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Predictive health – Configure thresholds for advanced diagnostics.
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Calibration – Factory valid for 5 years; use precision calibrator (e.g., Fluke 754) for field verification after extreme thermal events.
Environmental
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CJC stability – Avoid mounting near heat sources, air vents, or fans that create temperature gradients across the terminal block. This directly affects CJC accuracy.
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Operating temp – -40°C to +85°C; maintain rack temperature <70°C for long-term reliability.
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Warm-up – Allow 30 minutes for CJC thermal stabilization after power-up before relying on critical measurements.
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Humidity – 5-95% RH non-condensing.
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Vibration – 5g (10-500Hz) per IEC 60068-2-6.
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Clearance – Maintain 10mm airflow clearance.
Procurement
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Authentic sourcing – Buy from GE-authorized distributors or certified repair centers.
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Refurbished units – Request NIST-traceable CJC calibration certificate and minimum 1-year warranty.
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Storage – ESD-safe packaging with desiccant; shelf life 10 years at 25°C ±10°C, <60% RH.
Safety & Compliance
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Not SIL-rated – Trip logic implemented at Mark V CPU via 2-out-of-3 voting.
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CE/FCC – Complies with EN 61326-1 (industrial immunity) and FCC Part 15 Class A.
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ATEX – Not certified for hazardous areas; mount in purge-pressurized enclosure if required.
A-B 1746-NI4/B
A-B 1756-A10
NI SHC68-68-EPM
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