Eaton SD275X Industrial DIN Rail Signal Surge Arrester SPD
Product Overview
The SD275X is a high-performance AC power surge protection device (SPD) from Eaton's MTL SD series (Crouse-Hinds series), specifically engineered to safeguard sensitive electronic equipment, PLC systems, and industrial control panels from damaging voltage transients and lightning-induced surges on AC power supply lines.
With a nominal voltage rating of 240V AC / 320V DC and a high current handling capacity of 3A, the SD275X is the ideal solution for protecting 220-240V AC power circuits in industrial automation, process control, and hazardous area installations. The device features multistage hybrid protection circuitry with a maximum surge current capacity of 20kA.
Certified with ATEX (MTL03ATEX1527X) for use in potentially explosive atmospheres (Zone 2), the SD275X is the trusted choice for applications requiring certified AC power surge protection.
Model Number Decoding: SD275X
| Code Segment |
Meaning |
| SD |
Surge Protection Device (SPD) -- MTL SD series |
| 275 |
Nominal voltage rating -- 240V AC / 275V AC / 320V DC |
| X |
Denotes the high-current variant (3A nominal current) |
The "X" suffix distinguishes this model from standard SD series models by offering increased current handling capability (3A vs. 400mA), making the SD275X suitable for AC power protection applications.
Key Features & Benefits
- AC Power Line Protection: Specifically designed for 220-240V AC power supply circuits, protecting PLCs, DCS systems, and industrial control panels from destructive surges
- High Current Capacity (3A): Handles nominal currents up to 3A -- suitable for power supply protection applications requiring higher current handling
- 20kA Maximum Surge Current: Provides robust protection against lightning strikes and power grid switching transients with multistage hybrid protection circuitry
- Ultra-Slim DIN Rail Mounting: Ultra-compact design with 7mm width for standard 35mm DIN rail (top hat rail) installation, saving valuable panel space in crowded electrical enclosures
- ATEX Certified for Zone 2: Certified under ATEX Directive 2014/34/EU (Certificate MTL03ATEX1527X) for use in potentially explosive atmospheres -- Category 3G, Zone 2
- Fast Response Time: Responds to overvoltage events in less than 1 nanosecond, clamping transients before they can damage downstream equipment
- Low Series Resistance (0.1 Ω/line): Minimizes power loss and heat generation in the protected circuit
- Comprehensive Testing: Tested according to IEC 61643-21 for protection categories A2, B2, C1, C2, C3, and D1
- 10-Year Product Warranty: Backed by Eaton MTL's industry-leading "No Fuss" warranty
Technical Specifications
| Parameter |
Value |
| Manufacturer |
Eaton (Crouse-Hinds series MTL) |
| Series |
MTL SD Series |
| Product Model |
SD275X |
| Nominal Voltage AC (Un) |
240V / 275V |
| Nominal Voltage DC (Un) |
320V |
| Max. Continuous Operating Voltage (MCOV) |
275V AC / 339V DC |
| Nominal Current (In) |
3A (high-current variant) |
| Maximum Surge Current (8/20 μs) |
20kA |
| Nominal Discharge Current (8/20 μs) |
3kA / 5kA |
| Lightning Impulse Current (10/350 μs) |
1kA |
| Voltage Protection Level (Up) @ 1kV/ μs |
<700V |
| Voltage Protection Level @ In |
850V |
| Series Resistance |
0.1Ω per line |
| Max. Leakage Current |
50μA |
| Response Time |
<1ns |
| Mounting Method |
DIN rail (35mm top hat rail) |
| Product Width |
7mm (ultra-slim) |
| Product Height |
101.3mm |
| Product Depth |
99mm |
| Weight |
Approx. 70g |
| Wire Size |
12 AWG (2.5mm²) |
| Operating Temperature |
-40°C to +80°C |
| Storage Temperature |
-40°C to +80°C |
| Humidity |
5-95% RH (non-condensing) |
| Protection Mode |
AC power line protection for electronic equipment and I/O cables |
| Certifications |
ATEX (MTL03ATEX1527X), IECEx |
| Standards Compliance |
EN 60079-15:2010, EN IEC 60079-0:2018 |
| Test Categories (IEC 61643-21) |
A2, B2, C1, C2, C3, D1 |
| IP Rating |
IP54 |
| Warranty |
10 years |
Applications
The SD275X is specifically designed for AC power protection in demanding industrial environments:
| Industry |
Application |
| Industrial Automation |
Protection of PLCs, DCS systems, and industrial control panels from AC power line surges |
| Oil & Gas |
Offshore platforms, refineries, pipelines -- protects AC-powered instrumentation in Zone 2 hazardous areas |
| Chemical Processing |
Reactor monitoring systems, flow measurement equipment requiring AC power protection |
| Power Generation |
Steam/gas turbine control systems, boiler control panels, substation protection |
| Manufacturing |
Production line control systems, robotic cells, CNC machine power supplies |
| Hazardous Areas |
ATEX Zone 2 classified locations requiring certified AC power surge protection |
Suitable for protecting AC power supply circuits feeding sensitive electronic equipment in classified and non-classified areas.
Why Choose the SD275X?
- Purpose-Built for AC Power Protection -- Unlike standard SD series models (SD07, SD16, SD32, SD55) which are designed for 4-20mA signal loops, the SD275X is specifically engineered for 220-240V AC power supply protection, making it the correct choice for AC power line applications.
- High Current Capability -- With 3A nominal current rating, the SD275X handles the higher currents typical of power supply circuits, unlike standard SD series models rated for only 400mA.
- Certified for Hazardous Areas -- ATEX certified (Category 3G, Zone 2) with Certificate MTL03ATEX1527X, ensuring compliance for installations in potentially explosive atmospheres across Europe and internationally.
- Ultra-Slim Footprint -- At just 7mm width, the SD275X saves valuable panel space, allowing high-density mounting on DIN rails in crowded electrical enclosures.
- Proven MTL SD Series Reliability -- The SD series has been field-proven globally for high-performance surge protection with multistage hybrid circuitry, comprehensive IEC testing, and a 10-year warranty.
SD275X vs. Standard SD Series Models
| Model |
Voltage (Un) |
Nominal Current |
Series Resistance |
Primary Application |
| SD07X |
7V DC |
400mA |
2.2Ω |
Low voltage 4-20mA loops |
| SD16X |
16V DC |
400mA |
2.2Ω |
Medium voltage I/O |
| SD32X |
32V DC |
400mA |
2.2Ω |
Standard process I/O |
| SD55X |
55V DC |
400mA |
2.2Ω |
Higher voltage I/O |
| SD150X |
150V DC / 120V AC |
3A |
0.1 Ω |
110-120V AC power protection |
| SD275X |
240V AC / 320V DC |
3A |
0.1 Ω |
220-240V AC power protection |
The SD150X and SD275X form Eaton's high-current AC power protection family, with SD275X designed for 220-240V AC applications (European/Asian standard voltages).
Installation Information
| Parameter |
Detail |
| Mounting |
Standard 35mm DIN rail (top hat rail / T-section rail) |
| Terminals |
Screw terminals accepting 12 AWG wire |
| Grounding |
Simplified via DIN rail mounting |
| Orientation |
Any (no restriction) |
| Clearance |
Minimal -- ultra-slim 7mm width enables high-density installation |
The SD275X mounts easily on standard DIN rails, simplifying installation and grounding in new or retrofit applications.
Ordering Information
| Item |
Details |
| Part Number |
SD275X |
| Brand |
Eaton (Crouse-Hinds series MTL) |
| Product Family |
MTL SD Series -- SDX High-Current AC Power Variant |
| Catalog Number |
SD275X |
| Country of Origin |
India |
| Condition |
New, Original, Factory Sealed |
| Minimum Order Quantity |
1 piece |
| Warranty |
10 Years (Eaton "No Fuss" Warranty) |
| Shipping |
Immediate dispatch via DHL, FedEx, UPS, TNT |
Contact our sales team for volume pricing, datasheet downloads, or technical application support.
Compliance & Certifications
| Certification |
Status |
Details |
| ATEX |
✅ Certified |
MTL03ATEX1527X -- Category 3G, Zone 2 |
| ATEX Directive |
✅ Compliant |
2014/34/EU |
| Standards |
✅ Compliant |
EN 60079-15:2010, EN IEC 60079-0:2018 |
| IEC 61643-21 |
✅ Tested |
Categories A2, B2, C1, C2, C3, D1 |
| RoHS |
✅ Compliant |
Lead-free / RoHS3 compliant |
| Functional Safety |
✅ Suitable |
For use in SIL-rated loops per IEC 61508/61511 |
Related Products from MTL SD Series
| Model |
Voltage |
Current |
Series |
Primary Application |
| SD275X |
240V AC / 320V DC |
3A |
SDX |
220-240V AC power protection |
| SD150X |
150V DC / 120V AC |
3A |
SDX |
110-120V AC power protection |
| SD07X |
7V DC |
400mA |
SDX |
Low voltage, 4-20mA loops |
| SD16X |
16V DC |
400mA |
SDX |
Medium voltage I/O |
| SD32X |
32V DC |
400mA |
SDX |
Standard I/O |
| SD55X |
55V DC |
400mA |
SDX |
Higher voltage I/O |
| SD07R |
7V DC |
400mA |
SDR |
Standard resistance applications |
| SD55R |
55V DC |
400mA |
SDR |
Higher voltage standard resistance |
The MTL SD series offers a complete range of voltage ratings and performance variants to suit all power and I/O protection applications.
