Solve Control Cabinet Complexity with the SR3B261FU
Machine builders often face a common pain point: hard-wired relay logic consumes valuable panel space and makes late-stage design changes expensive. The SR3B261FU from Schneider Electric directly addresses this challenge. As part of the Zelio Logic series, this modular smart relay combines 26 I/O points with a 100-240V AC supply in a compact DIN-rail housing. It replaces dozens of discrete timers, counters, and auxiliary relays with one programmable device. The result is a smaller cabinet, faster commissioning, and simpler troubleshooting.
Key Parameters That Drive Panel Performance
I/O Count and Flexibility
The SR3B261FU provides 16 digital inputs and 10 relay outputs. Six of those inputs are configurable as analog inputs, which means you can monitor simple process variables without adding separate analog modules. Each relay output handles 5 A, so you can switch contactors, solenoids, and indicator lamps directly. This reduces the need for interposing relays and lowers total component cost.
Wide Supply Voltage Range
The module accepts 100-240V AC (85-264V, 50/60 Hz). That wide band means the same part number works across different regional power systems. For panel builders shipping machines worldwide, this simplifies inventory and reduces the risk of installing the wrong voltage variant.
Program Memory and Real-Time Clock
With 240 lines of ladder logic or 500 FBD blocks, the SR3B261FU handles moderate control tasks without a full PLC. The integrated real-time clock enables time-based functions such as scheduling, logging, and shift-based control. An LCD with navigation buttons allows on-site monitoring and quick parameter checks without a laptop.
Where the SR3B261FU Delivers Value
Replacement and Upgrade Projects
Many legacy panels still rely on aging relay banks. The SR3B261FU offers a direct upgrade path: 35 mm DIN rail mounting, screw terminals, and familiar ladder programming. Maintenance teams can replace worn hardware with an active-lifecycle product. This reduces downtime risk and extends the panel’s service life.
Building Automation and Lighting Control
In commercial buildings, the 100-240V AC inputs connect directly to standard control circuits. The real-time clock supports occupancy schedules and lighting sequences. The 5 A relay outputs switch lighting contactors and small loads without additional interfaces.
Small Machine Control
For packaging, labeling, or pump control, the 26 I/O points cover typical start/stop, interlock, and alarm functions. The compact 90 × 124.6 × 59.5 mm footprint fits tight enclosures. At 0.30 kg, it adds minimal weight to a DIN rail.
Installation and Setup Essentials
Mount the SR3B261FU on a 35 mm DIN rail inside a suitable enclosure. Keep AC supply wiring separated from low-level signal cables to reduce electrical noise. The operating temperature range of -20 to 55 °C suits most industrial environments. Before power-up, verify that input voltages match the 100-240V AC rating. Use the LCD and navigation buttons to confirm I/O status during commissioning. For programming, follow Schneider Electric’s Zelio Logic documentation and verify all safety interlocks independently.
Reliability and Maintenance Planning
The relay outputs carry a mechanical life of 10,000,000 cycles and an electrical life of 500,000 cycles at AC-12, 230V 1.5A per IEC 60947-5-1. For high-cycle applications, plan periodic inspection of output contacts. Check terminal tightness and remove dust from the enclosure during routine maintenance. Because the product is active in the Zelio Logic range, long-term spare parts availability supports a low total cost of ownership.
Compatibility and Integration Notes
The SR3B261FU communicates via extension modules, allowing I/O expansion when your application grows. It integrates with standard control panels and accepts 100-240V AC input signals. The real-time clock and LCD simplify standalone operation, while ladder or FBD programming supports integration into existing control schemes. Verify extension module compatibility with Schneider Electric documentation before ordering.
What to Verify Before You Buy
Confirm your required I/O count, output load type, and supply voltage. Check that 16 inputs and 10 relay outputs meet your control scheme. If you need analog inputs, note that six inputs are configurable for that purpose. For current lifecycle status and availability, contact SpareTechPLC. They supply industrial automation parts and can confirm lead times for the SR3B261FU.
Frequently Asked Questions
Can the SR3B261FU replace a small PLC?
For moderate control tasks with up to 26 I/O points, yes. It offers 240 lines of ladder logic or 500 FBD blocks, plus a real-time clock. For complex motion or high-speed tasks, choose a full PLC.
What is the supply voltage range?
The module accepts 100-240V AC, with an operating range of 85-264V at 50/60 Hz. This covers most industrial and commercial power systems.
How many analog inputs does it have?
Six of the 16 digital inputs are configurable as analog inputs. They accept 100-240V AC signals.
What is the relay output rating?
Each of the 10 relay outputs handles 5 A. Electrical life is 500,000 cycles at AC-12, 230V 1.5A per IEC 60947-5-1.
Is the SR3B261FU still in production?
Yes. Schneider Electric lists it as active in the Zelio Logic range, last verified in September 2026. Contact SpareTechPLC to confirm current availability.
