Product Core Brief
- Models: NRD108028 / 8RDB43655 / SA43655.E
- Brand: ALSTOM
- Series: ALSTOM Relay Output Board Family
- Core Function: 8-channel relay output board used to provide discrete trip, close, alarm, permissive, and interlock outputs in ALSTOM protection, control, and auxiliary cabinets.
- Product Type: Relay Output Module / Discrete Output Board / Plug-In Control Card
- Key Specs: 8 × SPDT relay outputs | Backplane-supplied power | Proprietary host interface | No front-port communication | Rack/plug-in installation | Revision-dependent ratings and firmware
- Condition: New Original / New Surplus
Product Introduction
ALSTOM NRD108028 / 8RDB43655 / SA43655.E is an ALSTOM relay output board referenced in spare-part channels as an 8-channel discrete output module for protection and control systems. It is typically installed as a plug-in board inside an ALSTOM host chassis, protection cabinet, or auxiliary control rack.
The module provides isolated relay outputs for alarm annunciation, breaker trip/close commands, permissives, interlocks, and discrete control signals. It communicates with the host controller through a proprietary backplane interface and does not usually carry independent Ethernet, ControlNet, or fieldbus ports on the front panel. Some third-party listings describe this part as an Ethernet/IP communication adapter, analog power metering module, or DCS network gateway; those descriptions conflict with the relay output board designation and should not be used as the basis for replacement.
Key Technical Specifications
| Parameter | Value |
|---|---|
| Full Model | ALSTOM NRD108028 / 8RDB43655 / SA43655.E |
| Product Type | 8-channel relay output board |
| System Platform | ALSTOM protection, control, and auxiliary cabinets |
| Core Function | Discrete relay outputs for trip, close, alarm, permissive, and interlock |
| Relay Outputs | 8 × SPDT (Form C), typical rating up to 2 A @ 30 VDC; confirm from nameplate |
| Power Supply | Backplane-supplied, typically 24–48 VDC from host |
| Communication | Proprietary backplane interface to host controller |
| Installation | Plug-in rack module for ALSTOM chassis |
Quality Control Process
- Visual and code check: Confirm NRD108028, 8RDB43655, and SA43655.E markings, revision code, and connector condition.
- Nameplate verification: Confirm relay output count, contact rating, supply voltage, and compatible ALSTOM chassis.
- Backplane interface check: Inspect plug-in connectors, pin alignment, and chassis slot compatibility.
- Functional check: Verify relay pickup/drop-out, contact continuity, LED/status indication, and host recognition where test fixtures allow.
- Final packing: Record test results, apply asset labels, and ship with connector and PCB protection.
Replacement Pitfall Guide
❗ Treat the three codes as one board family. NRD108028, 8RDB43655, and SA43655.E are commonly listed together as the same relay output board; still, confirm the exact revision.
❗ Do not treat it as an Ethernet/IP, ControlNet, or analog metering module. Listings describing Ethernet communication, power measurement, or DCS network adapter functions are not consistent with this relay output board.
❗ Verify contact rating. Typical listings show 8 × SPDT relays up to 2 A @ 30 VDC, but the installed nameplate and panel drawing must take priority.
❗ Confirm chassis and slot type. The board must match the ALSTOM plug-in slot, backplane pinout, and host configuration.
❗ Check application mapping. Trip, close, alarm, permissive, and interlock outputs must be verified against the original I/O map before commissioning.
Keep these in mind and you’ll cut 90% of rework time.
Compatibility Matrix & Benchmarks
| Original Model | Replacement / Successor Model | Compatibility Level | Migration Notes |
|---|---|---|---|
| ALSTOM NRD108028 / 8RDB43655 / SA43655.E | Same relay output revision | Direct | Like-for-like when revision, contact rating, slot, and host match. |
| ALSTOM 8RDB43655 | Other ALSTOM relay output board | Needs Adaptation | Confirm channel count, contact rating, backplane type, and I/O mapping. |
| ALSTOM relay output board | Non-ALSTOM relay module | Not Recommended | Backplane, addressing, and host configuration are typically incompatible. |
| ALSTOM relay output board | Modern digital output module | Needs Adaptation | Requires I/O review, wiring changes, and commissioning support. |
- Typical use: Substation protection and control cabinets, power plant auxiliary systems, industrial MCC/PLC panels, rail traction and signaling cabinets, legacy ALSTOM host gear, and discrete output expansion.
- Key verification points: NRD108028 / 8RDB43655 / SA43655.E revision, relay count, contact rating, supply voltage, chassis model, slot position, and host I/O map.
