GE DS3828BH5A

Parameters

Advantages & Features

• High Channel Density – A single GE DS3828BH5A replaces up to five individual 4–20mA output cards, saving rack space and reducing system cost in multi-actuator applications like variable inlet guide vanes, blow-off valves, and cooling water control.

• Programmable Dither per Channel – Each output channel on the GE DS3828BH5A has independent dither amplitude and frequency settings, allowing simultaneous control of different valve types (e.g., fast-acting fuel valves and slow-acting temperature valves) from one module.

• Current Monitoring and Diagnostics – Real-time comparison of commanded vs. actual current (±1.5% accuracy) detects open-wire, partial shorts, and actuator degradation. Faults are flagged to the Mark VIe controller within 50ms.

• Compact and Cost-Effective – For applications not requiring bi-directional current, the GE DS3828BH5A provides the most cost-effective solution per channel in the Mark VIe product family, with approximately 40% lower cost per point than using separate 3-channel modules.

• SIL 1 Capability – Suitable for non-safety critical loops but can be used in SIL 1 applications per IEC 61508 with appropriate external proof-testing.

Application Cases

• Gas Turbine Inlet Guide Vane (IGV) Control – A single GE DS3828BH5A drives five IGV actuators (4–20mA) in a multi-stage compressor, with dither reducing hysteresis in pneumatic positioners. The compact design allows integration in existing racks without adding extra slots.

• Combined-Cycle HRSG Attemperation – Controls up to 5 spray water control valves using 4–20mA signals. The GE DS3828BH5A provides open-load detection on each channel, alerting operators to disconnected wiring before steam temperature excursions occur.

• Blow-Off and Start-Up Vent Valves – In a 9E gas turbine package, five pneumatically actuated start-up bleed valves are sequenced using a single GE DS3828BH5A, with each channel independently ramped to avoid pressure surges during startup.

• Water/Wastewater Chemical Dosing – Drives five dosing pump frequency converters (4–20mA) for pH control, flocculant, and chlorine injection, with the module’s diagnostics detecting pump faults via current loop continuity monitoring.

Competitor Comparison

The GE DS3828BH5A occupies a unique niche: higher density than the DS3828BH3A with lower cost per channel, but without bi-directional capability or SIL 2 rating. It outperforms Siemens and ABB by offering built-in dither and diagnostics, features not found in their standard analog output modules.

Selection Suggestions

• Choose the GE DS3828BH5A when you need 5 or fewer unidirectional 4–20mA outputs for proportional valves, IGV actuators, or damper positioners. It is the optimal choice for cost-sensitive projects where bi-directional control is unnecessary.

• If your actuator requires bi-directional current (e.g., torque-motor servo valves with ±20mA), select the DS3828BH3A or DS3828BH3AH instead — the DS3828BH5A cannot source negative current.

• Verify that your actuator coil impedance is within 100–750Ω at 20mA. For higher impedance loads (>750Ω), the GE DS3828BH5A may not achieve full 20mA output due to voltage compliance limits — use a 24V supply at the upper end of the tolerance (+20%) to maximize compliance.

• For SIL 1 applications, the GE DS3828BH5A requires external proof-testing every 24 months. If SIL 2 is mandated, upgrade to the DS3828BH3A or DS3828BH3AH instead.

• Pair the GE DS3828BH5A with the matching TB500-5 terminal block (5-channel screw-clamp termination) for easy field wiring.

Precautions

• Current Limit Behavior – The GE DS3828BH5A limits output current to approximately 30mA (hard clamp). If your actuator requires >20mA for emergency override, the clamp will prevent exceeding 22mA — not suitable for “boost” functions.

• Common Ground – All 5 output channels share a common negative terminal. If your field actuators require isolated 4–20mA loops (e.g., multiple loop-powered transmitters), you must install individual loop isolators to avoid current sharing and ground loops.

• Dither Resonance – With 5 channels on one GE DS3828BH5A, ensure that dither frequencies are not set to identical values for valves that are mechanically coupled — this can cause beat frequencies and resonant vibrations. GE recommends staggering dither frequencies by at least 20Hz across channels (e.g., 200Hz, 220Hz, 240Hz, etc.).

• Cable Length – For runs exceeding 100m, cable capacitance can affect the GE DS3828BH5A‘s output stability. Use shielded twisted-pair cable with conductor resistance <50Ω/km and verify voltage at the actuator terminal is sufficient (minimum 12V across the load at 20mA).

• Power Supply Sizing – With all 5 channels at 20mA, total load current = 300mA (module) + 5 x 22mA (with losses) ≈ 410mA. Allow 30% margin and ensure your 24V supply can deliver at least 600mA per module to handle inrush current during power-up.

• Output Overvoltage – The GE DS3828BH5A is not protected against accidental connection to 24V DC on the output terminals. Back-feeding external voltage into any channel will damage the output DAC — always confirm wiring before energizing and use fuse protection on each output if external supplies share the same conduit.

• Calibration Interval – Factory calibration is valid for 24 months. For applications requiring ISO 17025 traceability, send the GE DS3828BH5A to an authorized GE service center for recalibration. Field calibration using a precision current source is possible but requires the Mark VIe calibration utility and a certified reference meter.