GE DS3815PRBA

Key Parameters

Power Supply Section:

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

• Excitation Outputs: Adjustable excitation for transducers (e.g., 3V, 5V, 10V DC, or 4–20mA loop power)

• Output Accuracy: ±0.05% regulation

• Ripple/Noise: <5 mV peak-to-peak

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

Relay Output Section:

• Output Channels: 16 or 24 Form-C (SPDT) relay outputs (depending on configuration)

• Contact Rating: 5A at 250V AC / 30V DC (resistive load)

• Relay Type: Standard single-coil latching or non-latching (field-configurable)

• Output Coil: 24V DC (from backplane or external supply)

• Diagnostics: Per-channel LED status, coil fault detection, fuse status indication, self-test on power-up

• Response Time: 10–15ms (relay operate time)

Common Section:

• Isolation: 2500V RMS channel-to-backplane

• Field Wiring: Integrated terminal blocks for direct field wiring

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

• Power Supply: +5V (logic), +24V (relay coils and field power) from backplane or external supply

• Physical: 6U VME single-slot board

• Key Features: Integrated power supply + relay outputs, Form-C contacts, 5A contact rating, adjustable excitation, extended temp range, high isolation

Advantages

• Integrated power + relay outputs – the DS3815PRBA combines sensor excitation and high-current relay outputs in a single module, reducing board count and simplifying system architecture.

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

• Stable sensor excitation – provides clean, regulated power for speed pickups, proximity probes, pressure transmitters, and other transducers.

• Adjustable excitation – allows matching excitation levels to specific sensor requirements.

• High-current relay outputs – 5A contact rating handles larger loads than solid-state outputs, suitable for solenoids, contactors, and alarm devices.

• Form-C contacts – provides both NO and NC outputs for fail-safe wiring.

• Coil fault detection – the General Electric DS3815PRBA monitors relay coil health for predictive maintenance.

• Visual diagnostics – per-channel LEDs and fuse status indicators simplify troubleshooting.

• 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 trip and shutdown circuits – the DS3815PRBA drives critical trip solenoids for fuel, steam, and lube oil emergency shutdown.

• Alarm annunciation – drives panel lamps, horns, and DCS alarm inputs with high-current relay outputs.

• Motor and valve control – controls auxiliary motors, solenoid valves, and isolation valves.

• Sensor excitation with relay control – powers field sensors while simultaneously providing relay outputs for discrete control.

• Fail-safe circuits – Form-C contacts provide both NO and NC options for fail-safe wiring.

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

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

vs Competitors & Separate Boards

Selection Tips

• Relay outputs + power – choose the DS3815PRBA when you need both sensor excitation and high-current relay outputs (5A) for driving solenoids, contactors, or alarm devices.

• Slot-limited installations – the General Electric DS3815PRBA reduces board count compared to separate power supply and relay output boards.

• Fail-safe wiring – Form-C contacts provide both NO and NC outputs, essential for critical trip circuits.

• Sensor compatibility – verify that the excitation voltage and current requirements of your sensors match the DS3815PRBA outputs.

• Load verification – ensure the 5A contact rating is sufficient for your loads; use external contactors for higher currents.

• 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 relay coils and ensure it does not exceed the DS3815PRBA total power rating.

• Spare strategy – keep one DS3815PRBA per 5–8 installed units, especially in critical trip and alarm applications.

• Wiring planning – plan field wiring terminations carefully to leverage the integrated terminal blocks efficiently.

Critical Precautions

• Power supply loading – do not exceed the DS3815PRBA current rating for any output. Overloading can cause voltage drop, overheating, or shutdown.

• Output voltage selection – verify that the DS3815PRBA output voltages are correctly configured before connecting sensors. Incorrect voltage can damage sensors.

• Output over-current – do not exceed the relay contact rating (5A). Overloading can weld contacts or cause overheating.

• Inductive loads – for DC solenoid and relay coil loads, install a flyback diode across the load to prevent voltage spikes from damaging the General Electric DS3815PRBA relay contacts or control circuitry.

• Field wiring – use appropriate wire gauge for field connections to the DS3815PRBA terminal blocks. Loose connections can cause intermittent faults or overheating.

• Fuse replacement – if a fuse status indicator shows a fault, verify the field wiring and load before replacing the fuse. Use only the specified fuse rating.

• Relay contact wear – for high-cycle applications, consider derating the DS3815PRBA relay contacts or using an external interposing relay.

• Cable shielding – use shielded cables for sensor and output wiring in electrically noisy environments. Ground the shield only at the DS3815PRBA end.

• Ground loops – use single-point grounding for all sensors and outputs connected to the DS3815PRBA to avoid ground-loop noise.

• Thermal considerations – ensure adequate cabinet cooling (>200 CFM); the DS3815PRBA can generate significant heat under full load.

• Self-test – allow the DS3815PRBA to complete its power-up self-test (~2 seconds) before relying on outputs.

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

• Hot-swap – never insert or remove the DS3815PRBA while the rack is powered.

• ESD handling – always use a grounded wrist strap; all components are ESD-sensitive.

• Storage – store spare DS3815PRBA boards in anti-static bags in a dry, temperature-controlled environment.