General Information

• Manufacturer: MTL Instruments (Schneider Electric)
• Product Series: MTL 800 Series (Intrinsically Safe Surge Protection)
• Product Type: Intrinsically Safe Surge Protector (IS Surge Arrester)
• Status: Active (commercially available as of current industrial supply data)
• Target Applications: Protection of communication lines (e.g., Ethernet, serial) and signal circuits in hazardous areas (Zone 0/1/2 for gas; Zone 21/22 for dust). Common uses include safeguarding PLC I/O modules, sensors, and communication interfaces in petrochemical, pharmaceutical, and mining industries.

Intrinsic Safety (IS) Certifications

• Certification Standards:
  • ATEX/IECEx: Complies with ATEX 2014/34/EU and IECEx standards for intrinsic safety.
  • Hazardous Area Ratings:
    • Gas Groups: IIA, IIB, IIC (compatible with most flammable gas atmospheres).
    • Temperature Classes: T4 (maximum surface temperature ≤ 135°C), suitable for high-temperature industrial environments.
    • Protection Levels: Ex ia IIC T4 Ga (for Zone 0, the most hazardous gas zone) and Ex ia IIIC T135°C Da (for Zone 20 dust zones).
• Safety Barrier Function: Acts as a passive safety barrier, limiting electrical energy (current/voltage) to levels below the ignition threshold of flammable mixtures in hazardous areas.

Electrical Specifications

1. Surge Protection Performance:
   • Protection Type: Metal Oxide Varistor (MOV) + Gas Discharge Tube (GDT) hybrid technology, providing multi-stage surge suppression for both common-mode and differential-mode surges.
   • Surge Current Rating (Ipp): 10 kA (8/20 µs waveform, per IEC 61000-4-5; standard for industrial surge events).
   • Voltage Protection Level (Up): ≤ 15 V (at nominal current), ensuring surge voltages are clamped to safe levels for connected equipment.
   • Response Time: < 1 ns (near-instantaneous reaction to transient surges, minimizing equipment exposure).
2. Circuit Parameters:
   • Nominal Voltage (Un): 24 V DC (compatible with standard industrial low-voltage circuits).
   • Maximum Continuous Operating Voltage (Uc): 30 V DC (safe for long-term operation under normal line voltage fluctuations).
   • Insertion Loss: < 0.5 dB (at 100 MHz), ensuring minimal signal attenuation for communication circuits (e.g., Ethernet, RS485).
   • Line Resistance: < 1 Ω, preventing voltage drops that could affect sensor or signal performance.

Physical & Environmental Specifications

• Dimensions:
  • 45 mm (Width) × 105 mm (Height) × 110 mm (Depth) (compact DIN rail-mount design for space-constrained control cabinets).
• Weight: Approximately 0.25 kg.
• Mounting: DIN rail mounting (compliant with EN 50022-35 standard, compatible with 35 mm top-hat rails common in industrial cabinets).
• Protection Class: IP20 (dust-protected, suitable for indoor installation in control cabinets; requires additional enclosure for outdoor use).
• Operating Conditions:
  • Temperature Range: -40°C to +70°C (wide range for extreme industrial environments, from cold storage to refineries).
  • Storage Temperature Range: -40°C to +85°C.
  • Relative Humidity: 5% – 95% (non-condensing, to avoid moisture-related electrical faults).
  • Vibration Resistance: 10 g (10 Hz – 500 Hz, per IEC 60068-2-6), ensuring durability in vibrating machinery (e.g., pumps, compressors).

Functional Features

1. Surge Detection & Suppression:
   • Automatically detects transient surges (e.g., from lightning, power grid switching, or electromagnetic interference) and diverts excess current to ground, protecting downstream equipment.
   • Self-restoring design: Resets to normal operation after surge events without manual intervention (no replaceable fuses required).
2. Diagnostic & Status Monitoring:
   • LED Indicator: Single LED (green = normal operation; red = module fault/surge event triggered), enabling quick visual status checks during maintenance.
   • Remote Monitoring (Optional): Some variants support contact output for remote fault signaling (e.g., to a PLC or SCADA system) for centralized maintenance alerts.
3. Installation Flexibility:
   • Wiring: Screw terminals (for 0.5 – 2.5 mm² copper cables) with cage-clamp design for secure, vibration-resistant connections.
   • Polarity Insensitivity: Accepts non-polarized wiring for simplified installation (no risk of reverse-connection damage).

Application & Compatibility Notes

• Compatible Circuits:
  • Signal lines: 4-20 mA analog sensors, RS232/RS485 serial communication, and low-speed Ethernet (up to 100 Mbps).
  • Power lines: 24 V DC auxiliary power for sensors, transmitters, and small actuators in hazardous areas.
• System Integration: Designed for use with MTL’s 800 Series intrinsic safety modules and Schneider Electric/Siemens industrial control systems (e.g., SIMATIC S7, Modicon M580).
• Compliance: Meets IEC 61643-12 (surge protection for low-voltage systems) and EN 60079-11 (intrinsic safety standards), ensuring regulatory compliance in global industrial markets.

Availability