Description
The GE IS410SRLYS2A (packaged board assembly) and IS400SRLYS2ABB (circuit board artwork/revision code) form the SRLY Relay Output Terminal Board within General Electric’s Speedtronic™ Mark VIe and Mark VIeS safety instrumented and turbine control systems. Designed for high-reliability digital output control, the SRLY board provides electromechanical relay contacts to drive solenoids, motor starters, trip circuits, and alarm annunciators across power generation and industrial process plants.
Key Specifications & Identification
| Attribute | Details |
| Manufacturer | General Electric (GE / GE Vernova) |
| Assembly Part Number | IS410SRLYS2A (Complete Terminal Board Assembly) |
| PCB Artwork Number | IS400SRLYS2ABB (Board Revision / Sub-Assembly) |
| Acronym / Family | SRLY (Simplex Relay Output Terminal Board) |
| System Compatibility | GE Speedtronic™ Mark VIe and Mark VIeS Control Platforms |
| Associated I/O Pack | IS220YDROH1A / IS200YDRO (Discrete Relay Output Pack) |
| Output Channels | 12 Electromechanical Relay Outputs (Form C / SPDT dry contacts) |
| Contact Voltage Rating | Up to 125 V DC / 120–240 V AC switching capability |
Primary System Functions
- High-Power Field Switching: Interfaces low-voltage logic commands from the Mark VIe controller with high-power field actuators, isolated interlocks, and plant annunciator panels.
- Direct I/O Pack Mounting: Features a direct-mount D-sub connector interface for IS220YDRO discrete output packs, enabling high-speed processing without intermediate interconnect cabling.
- Dry Contact Isolation: Provides individual Form C (Single Pole Double Throw – NO/NC/COM) contact isolation to eliminate cross-talk and prevent electrical faults from feeding back into internal IONet control buses.
- Contact State Feedback: Integrated voltage/current sensing networks on each channel pass relay state feedback to the control processor for fault logging and contact weld detection.
Servicing & Installation Guidelines
- Field Power Isolation: Relay contacts often switch external 125 V DC or 230 V AC utility circuits. Ensure all external field power feeds are de-energized and locked out (LOTO) prior to landing or disconnecting terminal blocks.
- I/O Pack Hot-Swapping: When configured in redundant Mark VIe architectures, the associated IS220YDRO I/O pack can be hot-swapped; however, verify that field relay switching logic will not disrupt operating machinery during replacement.
- ESD Precautions: Static electricity can damage onboard diagnostic ICs and optical isolators. Wear a grounded anti-static wrist strap during all installation and handling procedures.
- Terminal Screw Torque: Ensure terminal block screws are torqued to GE specification to maintain tight, low-resistance connections under turbine deck vibration conditions.
