Eaton MTL SD32R High Bandwidth Surge Protection Device with 20kA Surge Current Capacity and Ultra-Slim Design
The SD32R is a high-performance surge protection device (SPD) designed to safeguard sensitive electronic equipment, process I/O systems, and communication networks from damaging voltage transients and lightning-induced surges. Manufactured under the Eaton MTL / Weidmuller SD series platform, this ultra-slim DIN rail mount module combines multistage hybrid protection circuitry with a space-saving footprint, making it the ideal choice for industrial control cabinets with limited panel space.
With a maximum surge current capacity of 20kA (8/20 µs) and a sub-nanosecond response time (<1ns), the SD32R provides reliable, maintenance-free protection for 2-wire and 3-wire loops, including 4-20mA transmitters, HART communicators, PROFIBUS DP/PA, and RS485 networks.
| Parameter | Value |
|---|---|
| Model | SD32R |
| Nominal Voltage (DC) | 32 V |
| Nominal Voltage (AC) | 22 V |
| Nominal Current | 400 mA |
| Max. Surge Current (8/20 µs) | 20 kA |
| Nominal Discharge Current (8/20 µs) | 3 kA |
| Response Time | < 1 ns |
| Bandwidth | 0 - 50 MHz (up to 25MHz typical) |
| Mounting Method | DIN rail (35mm top-hat rail) |
| Resistance per Line | 10 Ω |
| Operating Temperature | -40°C to +80°C |
| Warranty | 10 years |
Specifications sourced from manufacturer datasheets.
The SD32R features an exceptionally slim footprint, allowing it to be mounted on standard 35mm DIN rails with high packing density. Multiple modules can be placed side-by-side without sacrificing ventilation or accessibility, effectively doubling as feed-through terminals to maximize cabinet space.
Utilizing advanced hybrid technology (combining gas discharge tubes, varistors, and transient voltage suppression diodes), the SD32R provides full line-to-line and line-to-ground protection. This 3-stage design ensures low let-through voltage and rapid response to both fast transients and high-energy surges.
With a wide bandwidth of up to 50MHz and low insertion loss, the SD32R maintains signal integrity for high-speed communication protocols. It is fully compatible with:
- PROFIBUS DP/PA
- RS485 / Modbus
- HART (Highway Addressable Remote Transducer)
- Fieldbus Foundation
- 4-20mA loops (conventional & smart)
The SD32R is ATEX certified as an intrinsically safe surge protector, making it suitable for use in potentially explosive atmospheres (gas and dust environments) without the need for heavy enclosures.
The SD32R includes a convenient loop disconnect feature (fuse-disconnect terminal block functionality), allowing technicians to open the current loop for commissioning, calibration, or maintenance without physically removing the surge protection device. This significantly reduces downtime and wiring errors.
| Application Area | Specific Use Cases |
|---|---|
| Process Control | 2-wire & 3-wire 4-20mA transmitters (pressure, temperature, flow) |
| Safety Systems | Emergency shutdown (ESD) systems, fire & gas detectors |
| Industrial Networks | PROFIBUS DP/PA, Modbus RS485, HART multiplexers |
| Low-Level Signals | Thermocouples, RTDs (PT100), strain gauges, load cells |
| Discrete I/O | PLC digital inputs/outputs, solenoid valves, alarms, LEDs |
For 3-wire RTD applications, consider the SDRTD or SD32T3. For 110-240V AC power supplies, consider SD150X / SD275X
Get in Touch
Have questions about our products or want to discuss a custom order? Our team is ready to help you.