MTL 831C Zener Barrier | 1-Ch, 250V, 4-20mA, 24V, 90mA, IS, FM/ATEX Specs

MTL 831C Zener Barrier | 1-Ch, 250V, 4-20mA, 24V, 90mA, IS, FM/ATEX Specs

MTL 831C zener barrier specifications. 1-channel, 250V max, 4-20mA, 24V DC, 90mA, intrinsic safety. FM/ATEX approved for hazardous area protection.

Product Overview

The MTL 831C​ is a single-channel zener safety barrier​ from MTL's 800 series, designed for intrinsic safety protection​ in hazardous areas. This module is approved for use in Zone 1 hazardous locations, provides 250V maximum input voltage​ protection, and is rated for 24V DC systems​ with 90mA current capacity. The "831C" designation identifies this specific zener barrier configuration. This device limits energy to safe levels for connected field instruments in explosive atmospheres, protecting both the control system and hazardous area equipment.

Technical Specifications

Note: Specifications are based on MTL 831C technical documentation. The "C" suffix may indicate specific approval or configuration. Always verify with the latest product datasheet for your region.

Key Features

• Intrinsic Safety Protection:​ Limits energy to prevent ignition in hazardous areas

• FM/ATEX/IECEx Approved:​ Certified for global use in hazardous locations

• High Input Voltage:​ 250V maximum input for robust system protection

• 4-20mA Compatible:​ Designed for standard process control signals

• Compact Design:​ Single-channel, space-efficient DIN rail mounting

• Clear Marking:​ Easy identification of safe and hazardous area connections

• Robust Construction:​ Durable polycarbonate housing

• Maintenance-Free:​ No moving parts, no calibration required

• Wide Temperature Range:​ -40°C to +70°C operation

• Global Approvals:​ Suitable for international projects

Entity Parameters (for System Design)

Installation Requirements

1. Ground Connection:​ Zener barriers must​ be connected to a high-integrity earth ground (typically < 1 Ω resistance)

2. Enclosure:​ Must be installed in a suitable enclosure (minimum IP54 for hazardous area applications)

3. Separation:​ Maintain minimum 50mm separation between safe and hazardous area wiring

4. Labeling:​ Proper labeling of safe and hazardous area connections is required

Typical Applications

• Process Industries:​ Connection of 4-20mA transmitters in oil & gas, chemical, pharmaceutical plants

• Temperature Measurement:​ RTD and thermocouple transmitters in hazardous areas

• Pressure/Level Transmitters:​ Field instruments in Zone 1 locations

• Analytical Instruments:​ Gas detectors, pH meters, conductivity sensors

• Flow Measurement:​ Flow transmitter signals from hazardous areas

• Control Valve Positioners:​ Signal to valve positioners in explosive atmospheres

• Any 4-20mA signal​ from equipment installed in Zone 1 hazardous locations

Important Technical Notes

1. Grounding is Critical:​ The zener barrier must be properly grounded​ to function safely. Use a dedicated ground conductor (minimum 4 mm² copper) connected directly to the ground bus.

2. System Certification:​ The entire loop (power supply, barrier, field device, and wiring) must be certified as intrinsically safe. Use only approved components.

3. Cable Parameters:​ Ensure field cable capacitance and inductance do not exceed Co and Lo values. Typical values: 150-200 nF/km for capacitance, 0.4-1.0 mH/km for inductance.

4. Power Supply:​ Use an approved intrinsically safe power supply. The power supply voltage must not exceed the barrier's Ui rating (250V).

5. Installation Location:​ Install in the safe area, as close as possible to the hazardous area boundary.

6. Wiring Separation:​ Maintain physical separation (minimum 50mm) between intrinsically safe and non-intrinsically safe wiring. Use separate cable trays or partitions.

7. Certification Verification:​ Check that the barrier's certification matches the hazardous area classification (Zone 1, IIC, T6) and the specific gas group of your application.

8. Maintenance:​ While maintenance-free, periodic inspection of ground connections and visual inspection for damage is recommended.

Note: This data sheet provides general specifications for the MTL 831C zener barrier. For complete installation guidelines, certification details, system design requirements, and safety instructions, consult the official MTL 800 Series Technical Manual. Always verify that the product configuration matches your specific hazardous area requirements.