MTL SD07X Surge Protector with 2.2Ω Low Resistance 7V DC 5V AC 400mA Current Capacity DIN Rail SPD
The MTL SD07X is a high-performance, low-resistance surge protection device (SPD) from Eaton's Crouse-Hinds MTL SD Series, specifically designed for low voltage signal circuits requiring minimal series impedance. With a nominal voltage rating of 7V DC / 5V AC and an ultra-low series resistance of just 2.2 Ω per line, the SD07X is the ideal solution for protecting sensitive thermocouple (THC) inputs, 4-20mA loops, emergency shutdown systems, and fire and gas detectors in industrial process control environments.
As part of the SDX series, this device delivers full hybrid surge protection without the additional fuse/disconnect feature, making it the perfect choice for applications where low loop resistance is critical for measurement accuracy.
- Ultra-Low Series Resistance - 2.2Ω Per Line: Minimal 2.2 Ω series resistance per line ensures negligible impact on sensitive low-level signals, ideal for thermocouple and millivolt-level measurements.
- Optimized for Low Voltage Applications: Rated at 7V DC / 5V AC for protecting low-voltage signal circuits including thermocouple inputs, 4-20mA current loops, emergency shutdown systems, and fire and gas detection systems.
- Proven Hybrid Protection Circuitry: Advanced multistage hybrid technology combining gas discharge tubes, varistors, and transient voltage suppression diodes for low let-through voltages and robust surge current handling.
- Ultra-Slim Space-Saving Design: Exceptionally slim footprint allows for high packing densities on DIN rails with individual modules that can "double-up" as feed-through terminals.
- Hazardous Area Certified: ATEX and IECEx certified for use in potentially explosive atmospheres (Zone 2), complying with IEC 60079-0:2017 and IEC 60079-7:2015 standards.
- Simple DIN Rail Installation: Snap-on mounting to standard 35mm top-hat DIN rail with automatic grounding via the DIN rail clip.
- 10-Year Product Warranty: Backed by Eaton MTL's industry-leading 10-year product warranty for long-term reliability.
| Parameter | Value |
|---|---|
| Model | SD07X |
| Manufacturer | Eaton MTL (Crouse-Hinds series) |
| Series | SDX Series (Low Resistance) |
| Nominal Voltage (DC) | 7 V |
| Nominal Voltage (AC) | 5 V |
| Nominal Current (In) | 400 mA |
| Maximum Surge Current (8/20 µs) | 10-20 kA |
| Nominal Discharge Surge Current (8/20 µs) | 3 kA |
| Series Resistance | 2.2 Ω per line |
| Maximum Leakage Current | 500 µA |
| Maximum Continuous Operating Voltage (MCOV/Uc) | 7.7 V |
| Voltage Protection Level (Up) @1kV/ µs | <12 V |
| Residual Voltage @Isn | 30 V |
| Bandwidth (fG) | 25 kHz (0-25 MHz) |
| Number of Terminals | 2 terminals (2-wire protection) |
| Mounting Type | DIN rail (35mm top-hat rail) |
| Operating Temperature | -40°C to +80°C |
| Warranty | 10-year limited warranty |
| Certification | Status | Details |
|---|---|---|
| ATEX | Certified | II 3 G Ex nA IIC T5 Gc |
| IECEx | Certified | IECEx BAS 19.0108X |
| CSA | Certified | For North American installations |
| BASEEFA | Certified | UK certification |
| RoHS | Compliant | Restriction of Hazardous Substances |
| Standards | Compliant | IEC 60079-0:2017, IEC 60079-7:2015 |
| Application Area | Specific Use Cases |
|---|---|
| Temperature Measurement | Thermocouple (THC) inputs - Types J, K, T, E, R, S, B |
| Process Control | 4-20mA current loops (low-power transmitters) |
| Safety Systems | Emergency shutdown (ESD) systems |
| Fire & Gas Detection | Fire detectors, gas detectors, flame sensors |
| Low-Level Signals | Millivolt-level measurements, strain gauges |
| Hazardous Areas | Oil & gas, chemical, pharmaceutical, mining facilities |
The SD07X is particularly well-suited for thermocouple applications where minimal series resistance is critical to maintaining signal integrity and measurement accuracy.
- Snap the SD07X onto standard 35mm top-hat DIN rail until it clicks securely into place
- Ensure proper grounding through the DIN rail (automatic when mounted on grounded rail)
- The ultra-slim footprint allows high-density side-by-side mounting
The SD07X features two terminals for 2-wire loop protection:
- Terminal 1: Signal/power positive (+) from field side
- Terminal 2: Signal/power negative (-) from field side
- The device connects in series with the protected circuit
- Series resistance of 2.2Ω is added to the loop - suitable for most thermocouple and 4-20mA applications
- The device provides no fuse/disconnect feature (use SD series if disconnect required)
- Follow local electrical codes for proper installation
- ✅ Ultra-low resistance - 2.2Ω per line for minimal signal impact
- ✅ Optimized for thermocouples - Perfect for THC and millivolt signals
- ✅ 400mA current capacity - Suitable for most low-power loops
- ✅ 3kA nominal discharge - Handles severe transient events
- ✅ <12V protection level - Superior clamping performance
- ✅ 25kHz bandwidth - Maintains signal integrity
- ✅ ATEX & IECEx certified - Suitable for hazardous areas
- ✅ Ultra-slim design - High packing density on DIN rails
- ✅ Simple DIN rail mounting - Quick and secure installation
- ✅ 10-year warranty - Long-term reliability assurance
The MTL SD07X Surge Protector delivers reliable, high-performance protection for low voltage signal circuits, with special optimization for thermocouple (THC) applications. With its ultra-low 2.2 Ω series resistance, 7V DC / 5V AC rating, <12V protection level, and hazardous area certifications, the SD07X is the ideal choice for engineers seeking to protect sensitive low-level instrumentation without compromising measurement accuracy.
Protect your sensitive thermocouple and low-level signal circuits with MTL SD07X - the low-resistance surge protection solution for harsh and hazardous environments.
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