GE DS3815PXCA

Key Parameters

Power Supply Section:

• Power Outputs: Multiple regulated DC outputs (+5V, ±15V, +24V, and configurable auxiliary outputs)

• Excitation Outputs: Adjustable excitation for transducers, including IEPE constant current (4mA) for accelerometers

• Output Accuracy: ±0.05% regulation

• Ripple/Noise: <3 mV peak-to-peak (ultra-low noise for sensitive vibration measurements)

• Diagnostics: LED status indicators for each output, over-voltage/over-current protection, thermal shutdown, output voltage monitoring

Vibration Input Section:

• Input Channels: 4 or 8 differential vibration inputs (depending on configuration)

• Input Types: Accelerometer (IEPE/ICP®), velocity (mV/mm/s), proximity probe (eddy-current), or general-purpose voltage (software/jumper-selectable per channel)

• Signal Conditioning: Integrated IEPE excitation (constant current), charge amplifier (for piezoelectric sensors), integration (velocity to displacement), and programmable filtering

• Excitation: 24V DC, 4mA constant current (IEPE)

• Frequency Range: 0.5 Hz to 10 kHz (programmable high-pass and low-pass filtering)

• Resolution: 18-bit ADC with ±0.05% accuracy (high precision)

• Measurement Parameters: Acceleration (g), Velocity (mm/s or in/s), Displacement (µm or mils) – software-selectable integration with drift compensation

• Diagnostics: Per-channel LED status, transducer fault detection (open/bias/overload), over-range detection, signal quality monitoring

Common Section:

• Isolation: 2500V RMS channel-to-backplane

• Temp Range: –40°C to +85°C (extended)

• Power Supply: +5V (logic), +24V/48V (field power) from backplane or external supply

• Physical: 6U VME single-slot board

• Key Features: Integrated power supply + vibration inputs, IEPE excitation, 18-bit ADC, programmable filtering, acceleration/velocity/displacement output, extended temp range, high isolation

Advantages

• Integrated power + vibration measurement – the DS3815PXCA combines sensor excitation and dedicated vibration input channels in a single module, reducing board count and simplifying system architecture.

• Space-saving – replaces up to three separate boards (power supply, vibration input, and excitation supply) with one module.

• Ultra-low noise power – <3 mV ripple provides exceptionally clean power for sensitive vibration measurements.

• Integrated signal conditioning – includes excitation, charge amplification, filtering, and integration circuitry, eliminating the need for external signal conditioners.

• Multi-parameter measurement – can output acceleration, velocity, or displacement from a single sensor input.

• IEPE/ICP compatibility – supports modern piezoelectric accelerometers with built-in electronics.

• Proximity probe support – can also interface with eddy-current probes for shaft relative vibration.

• Transducer diagnostics – detects open circuits, bias faults, and overload conditions, alerting the system to sensor issues.

• Programmable filtering – the General Electric DS3815PXCA allows setting high-pass and low-pass filters to reject unwanted noise.

• High accuracy – 18-bit ADC with ±0.05% accuracy ensures precise vibration measurement for early fault detection.

• Extended temperature range – operates from –40°C to +85°C for harsh environments.

• Comprehensive protection – over-voltage, over-current, and thermal protection safeguard the board and connected field devices.

• High isolation – 2500V RMS isolation protects the backplane from field-side faults.

• Drop-in compatible – works with all Mark IV backplanes and processor configurations.

Applications

• Turbine shaft vibration monitoring – measures relative shaft vibration using eddy-current proximity probes or absolute shaft vibration using accelerometers.

• Bearing vibration monitoring – the General Electric DS3815PXCA monitors bearing housing vibration for early detection of bearing wear, imbalance, and misalignment.

• Casing vibration monitoring – measures casing vibration for turbine structural integrity assessment.

• Compressor and pump vibration monitoring – used for vibration monitoring in gas turbine-driven compressors and pumps.

• Condition monitoring and predictive maintenance – provides vibration data for trending, FFT analysis, and fault diagnosis.

• Offshore and harsh environments – extended temperature range makes it suitable for demanding applications.

• Retrofits – replaces separate power supply and vibration input boards with a single, integrated solution.

vs Competitors & Separate Boards

Selection Tips

• Vibration monitoring + power – choose the DS3815PXCA for integrated vibration measurement with sensor excitation in a single module.

• Slot-limited installations – the General Electric DS3815PXCA reduces board count compared to separate power supply and vibration input boards.

• IEPE accelerometer compatibility – the built-in IEPE excitation eliminates the need for external signal conditioners.

• Measurement type – select the appropriate output parameter (acceleration, velocity, or displacement) for your application.

• Sensor compatibility – verify that your vibration sensors (accelerometer, velocity, proximity probe) are supported.

• Filtering requirements – configure the high-pass and low-pass filters to reject noise while preserving the vibration frequency band of interest.

• Harsh environments – the extended temperature range makes it suitable for offshore, desert, or unheated cabinet installations.

• Power loading – calculate the total current draw of all connected sensors and ensure it does not exceed the DS3815PXCA total power rating.

• Spare strategy – keep one DS3815PXCA per 5–8 installed units, especially in critical rotating equipment applications.

• Calibration – periodically verify vibration measurement accuracy using a portable vibration calibrator or reference sensor.

Critical Precautions

• IEPE sensor power – for IEPE accelerometers, ensure the DS3815PXCA excitation voltage and current (typically 24V DC, 4mA) are correctly configured. Incorrect settings can damage the sensor.

• Proximity probe compatibility – eddy-current probes require specific excitation voltage and calibration; verify the General Electric DS3815PXCA is configured for the correct probe type.

• Frequency range – set the high-pass and low-pass filters appropriately. Too high a high-pass cutoff can miss low-frequency vibration components; too low a low-pass cutoff can let noise through.

• Integration selection – when selecting velocity or displacement output, ensure the integration algorithm is correctly configured. Double integration can introduce low-frequency drift.

• Sensor wiring – use shielded twisted-pair cables for vibration sensor connections. Ground the shield only at the DS3815PXCA end to prevent ground loops.

• Transducer fault detection – if the DS3815PXCA detects a transducer fault, verify sensor and cabling integrity before replacing the board.

• Output voltage selection – verify that output voltages are correctly configured before connecting sensors. Incorrect voltage can damage sensors.

• Ground loops – use single-point grounding for all vibration sensors to avoid ground-loop noise that can mask true vibration signals.

• Thermal considerations – ensure adequate cabinet cooling (>200 CFM); the DS3815PXCA can generate significant heat under full load.

• Self-test – allow the DS3815PXCA to complete its power-up self-test (~2 seconds) before relying on vibration readings.

• Calibration intervals – schedule periodic calibration verification (every 6–12 months) to maintain accuracy.

• Hot-swap – never insert or remove the DS3815PXCA while the rack is powered.

• ESD handling – always use a grounded wrist strap; sensitive analog and charge amplifier components are ESD-sensitive.

• Storage – store spare DS3815PXCA boards in anti-static bags in a dry, temperature-controlled environment.