Description
Application Scenarios
In a municipal water treatment facility, the main RX3i CPU rack resides in the central control room while pump station I/O is distributed across satellite cabinets hundreds of meters away in outdoor MCC buildings. Engineers face a persistent challenge: running dedicated 120VAC feeders to each remote rack introduces ground loop noise, and power sags during pump motor starts cause intermittent I/O dropouts that disrupt flow control. By installing the GE IC694PWR321B in each expansion backplane, the facility achieves independent, isolated power rails at every remote location, eliminating cross-rack interference. The module’s 20ms ride-through time allows each rack to survive brief voltage dips when large motors engage, preventing nuisance resets that previously required manual intervention. This architecture reduces wiring complexity and cabinet footprint compared to running individual power supplies for each I/O group.
Parameter
| Parameter | Value/Description |
|---|---|
| Product Model | IC694PWR321B (Series B revision of IC694PWR321) |
| Manufacturer | GE Fanuc / Emerson |
| Product Category | Serial Expansion Power Supply Module |
| Nominal Input Voltage | 120/240 VAC or 125 VDC — auto-ranging, no jumper selection required |
| Input Voltage Range | 85 to 264 VAC / 100 to 300 VDC — tolerates plant mains variations and battery feeds |
| Total Output Power | 30 Watts maximum across all outputs |
| +5 VDC Output | 15 Watts max (5.0–5.2 VDC nominal) — powers backplane logic circuits |
| Relay +24 VDC Output | 15 Watts max (24–28 VDC) — energizes relay coils on output modules |
| Isolated +24 VDC Output | 20 Watts max (21.5–28 VDC) — supplies field devices without ground loops |
| Isolation Rating | 1500 VAC input-to-backplane for 1 minute |
| Ride-Through Time | 20 ms minimum at full load — maintains outputs during brief power interruptions |
| Protection Features | Over-current shutdown, over-voltage cutoff, short-circuit protection, internal 2A fuse |
| Mounting Position | Leftmost slot of RX3i serial expansion backplane |
| Operating Temperature | 0°C to +60°C |
Technical Principles and Innovative Values
- Innovation Point 1 — Universal Auto-Ranging Input: The IC694PWR321B accepts both AC and DC input without configuration changes. This eliminates the need for separate AC and DC power supply variants, simplifying spare parts inventory and reducing installation errors in facilities with mixed power sources.
- Innovation Point 2 — Triple-Isolated Output Architecture: Unlike basic power supplies that provide only a single 24V rail, the IC694PWR321B delivers three independently regulated outputs. The isolated +24 VDC rail prevents field wiring faults from propagating into backplane logic, a critical safety feature in plants where sensors operate near high-voltage equipment.
- Innovation Point 3 — 20ms Ride-Through Capability: Internal hold-up capacitors maintain valid output voltages for at least 20 milliseconds during input power interruptions. This allows the CPU to complete current scan cycles without resetting, preventing data loss during generator transfers or upstream breaker operations.
- Innovation Point 4 — Compact Expansion Architecture: By powering remote racks independently, the IC694PWR321B enables system integrators to add I/O capacity in distant motor control centers or skid enclosures without duplicating CPU hardware or running dedicated power feeders from the main panel.
