Description
Product Introduction
The GE is a TMR relay terminal board acting as the high-current output stage for Mark VIe systems, bridging the TREA processor to field devices like ESD solenoids and annunciator panels. It executes the voted 2oo3 logic, ensuring a single processor fault doesn’t prevent a mandatory trip or cause a spurious shutdown.
This “H2AED” revision features enhanced contact materials and diagnostic feedback circuits compared to older TREG variants. It houses 16 independent SPDT relays, typically rated for 5 A at 250 V AC. Actuation response is sub-10 ms once the vote is cast, maintaining the safety loop integrity .
IS200TREAH2AED
Key Technical Specifications
- System Role: TREA Terminal (TMR Relay Outputs)
- Relay Count: 16 Independent (SPDT / Form C)
- Coil Voltage: 24 Vdc (Range 18–32 Vdc)
- Contact Rating: 5 A @ 250 V AC / 5 A @ 30 V DC (Resistive)
- Voting Logic: 2oo3 (Two-out-of-Three Hardware Voting)
- Isolation: 1500 Vrms (Coil to Contact), 2500 Vrms (I/O to Logic)
- Diagnostics: Contact Weld Detect, Coil Open Detect
- Connectors: 2x 50-pin Ribbon (To TREA Proc), Barrier Strips (Field)
- Coating: Conformal Coated (AED Suffix – Enhanced)
- Temp Range: -30 °C to +65 °C (Operational)
- Compliance: SIL-2 Capable (In TMR Architecture)
Quality Control Process (Engineer’s Perspective)
- Incoming Verification: Match the GE serial to the manifest. Inspect the 16 relay bodies for cracked cases—vibration fatigue is real. Check the barrier terminal screws for galvanic corrosion on the copper lugs.
- Live Functional Test: Rig with 24 Vdc coil supply and 120 V AC load sim. Cycle all 16 relays at 1 Hz for 24 hrs. We scope the NO/NC transitions; bounce time must stay under 5 ms to avoid chattering the turbine trip.
- Electrical Parameter Test: Back-probe the 24 Vdc coil input with a Fluke 115. Megger the 250 V AC field terminals to chassis at 500 V; leakage must hold >10 MΩ to survive lightning surges.
- Diag Verification: Trigger a simulated “Weld” fault via the test header. The board must flag the channel red—well, technically the TREA processor interprets it, but the hardware sensing circuit is on this board.
- Final QC & Packaging: Exercise relays 50 cycles to seat the wipers. Bag in rigid ESD foam. Label “QC Passed – Trip/Diag Verified” with the date.
Replacement Pitfall Guide
❗ TMR Voting Logic: The GE is one of three (R, S, T). Mixing this “H2AED” revision with an older “H1A” in the same triplet causes “Hardware Mismatch” and forces the protection to Simplex mode (losing redundancy).
❗ Common vs Isolated: These relays are typically Form C (Common, NO, NC). Landing the 125 Vdc Trip Bus on the “NO” terminal while the logic expects “Common” leaves the solenoid permanently de-energized. Verify the wiring diagram for “Fail Safe Open” vs “Close”.
❗ Coil Polarity: The 24 Vdc coil feed (from TREA pack) is polarized. Reversing the P1/P2 ribbon cables back-feeds negative voltage into the sense lines, causing “Diag Fault” LEDs and voting errors.
❗ Contact Rating: Rated 5 A. Connecting them directly to a large ESD solenoid (e.g., 8 A inrush) welds the contacts shut, failing the “Fail Safe” open requirement during a shutdown.
❗ ESD to Ribbons: The 50-pin headers go to the TREA processor. Discharge to the panel frame before unplugging—critical in dry turbine halls (common in northern China winters).
Keep these in mind and you’ll cut 90% of rework time.
IS200TREAH2AED
Compatibility Matrix & Benchmarks
- GE → GE IS200TREAH1A : Needs Adaptation — AED has enhanced diags; verify TMR triplet uniformity in ToolboxST.
- GE → GE IS200TREA (Processor) : Direct — Physical mate for the TMR Relay Processor.
- GE → GE IS200TREGH1BEC : Incompatible — TREG is for 125V Trip Bus; TREA is for 24V/120V Logic.
- Actuation Time: < 10 ms (Coil Energize to Contact Close)
- Vote Resolution: < 20 ms (TMR Disagree detection)
- Isolation Test: 1500 Vrms (Coil to Contact, 1 min)
