Technical Specifications

• Product Model: MTL 4021S
• Brand: Eaton MTL Instruments
• Series: MTL4000 Series Isolating Interface Units
• Warranty: One Year
• Input Voltage: 20–35 VDC auxiliary supply
• Operating Temperature: -20 °C to +60 °C
• Storage Temperature: -40 °C to +85 °C
• Response Time: Fast digital switching for on/off field control
• Protection Class: IP20, DIN rail cabinet mounting
• Isolation Rating: 250 VAC isolation between safe area and hazardous area circuits
• Output Voltage: Max 25.5 VDC open circuit
• Rated Current Range: Max 110 mA short-circuit; typical usable load ≤50 mA
• Communication Interface: Screw terminal wiring for control input, override input and field output
• Certifications: ATEX, IECEx, FM; suitable for Zone 0, IIC T4-T6 hazardous locations
• Overload Capacity: Built-in energy limiting intrinsic safety protection, short-circuit current limiting
• Dimensions: 12.5 mm × 99 mm × 114.5 mm slim housing
• 

Application Scenarios

• Oil & Gas Refinery Hazardous Areas: Controls intrinsically safe solenoid valves for process isolation and emergency shutdown circuits. ATEX certification supports installation inside Zone 0 and Zone 1 classified areas.
• Petrochemical Processing Plants: Drives local alarm indicators and purge valve actuators. Override input supports safety system interlock functions to disable field devices during abnormal plant conditions.
• Pharmaceutical & Chemical Batch Facilities: Executes control for small IS valve actuators inside classified production zones. Slim DIN rail form factor optimises limited cabinet space.
• Natural Gas Compressor Stations: Provides safe switching for remote pilot valves and warning beacons. Energy-limited output prevents ignition risks from wiring faults in field instrument loops.