Description
Component Snapshot At-a-Glance
- Model: IS220PSFDH1A
- Alt. P/N: None (Direct replacement only)
- Product Series: GE Speedtronic Mark VI / VIe
- Hardware Type: Flame Detector Power Supply (PSFD) I/O Pack
- Key Feature: 335 VDC isolated high-voltage output, convection-cooled
- Primary Field Use: Supplies regulated high voltage to UV/IR flame detectors on TRPG turbine protection boards
IS220PDIAH1A
Hard-Numbers: Technical Specifications
- Input Voltage: 24–28 VDC (Nominal 28 VDC)
- Max Input Voltage: 29.4 VDC
- UVLO Range: 22.1–26.4 VDC
- Output Rating: 335 VDC @ 5 mA (7 mA current limited)
- Isolation Rating: 1700 VDC (Output to Input)
- Inrush Current: 550 mA (40 µs), 300 mA steady-state
- Power Draw: 4.1 W (Full Load)
- Operating Temp: -30°C to +65°C
- Protection: 385V MOV output overvoltage, internal current limiting
- Cooling: Convection (No fans)
- Weight: ~0.43 kg
- Dimensions: 263 × 58 × 28 mm
- Certifications: Class I Div 2, Zone 2 hazardous locations
The Real-World Problem It Solves
Flame detectors need stable, isolated high voltage to operate reliably. Unregulated or noisy power causes false flameout trips and missed combustion faults.Where you’ll typically find it:
- Mounted directly above TRPG (Gas Turbine Trip Protection) boards
- Gas turbine combustion chambers (UV/IR scanner loops)
- TMR (Triple Modular Redundant) safety systems for 1oo3 voting
Bottom line: delivers clean, isolated 335VDC to keep flame detectors online and turbine safety systems functional.
Hardware Architecture & Under-the-Hood Logic
is a passive, non-microprocessor power converter. It uses a high-frequency inverter and isolation transformer to step 28VDC to 335VDC.
- 28 VDC input feeds from JPDL power distribution board
- Input protection circuit filters transients and limits inrush
- DC-DC converter generates isolated high-voltage output
- Current limiter caps output at 7 mA to protect detector wiring
- 385V MOV clamps voltage spikes on detector lines
- Front-panel LEDs monitor input, output, and fault status
- Convection vents dissipate heat without moving parts
IS220PDIAH1A
