MTL 8202-HO-IS

Description

Model Series

Technical Specifications

Functional Features

• Hermetically sealed construction — all internal components are enclosed in a welded metal can, providing immunity to humidity, dust, and chemical contamination; ensures long-term calibration stability
• Galvanic isolation via magnetic coupling — input and output circuits are completely isolated using transformer coupling, eliminating ground loops and providing noise immunity
• High output current (100 mA per channel) — capable of powering multiple field instruments (transmitters, valves, solenoids) from a single barrier channel without external power supplies in the hazardous area
• Dual-channel configuration — two independent barrier channels in a single housing, reducing panel space and wiring complexity
• Intrinsic safety certification for IIC gas group — approved for the most hazardous atmospheres including hydrogen and acetylene (T6 temperature class)
• Configurable input/output signal types — supports 4–20 mA, 0–20 mA, 0–10 VDC, and 1–5 VDC signals via internal DIP switches or jumpers
• Active and passive output modes — active output provides powered signal to field instruments; passive output allows loop-powered 4–20 mA transmitters
• Built-in diagnostic LEDs — per-channel power, fault, and signal status indicators for rapid troubleshooting
• Fail-safe design — in the event of internal failure, the barrier limits energy to the hazardous area to below ignition levels (intrinsically safe by design)
• Wide supply voltage range (18–30 VDC) — accommodates most standard 24 VDC control system power supplies without adjustment
• Low power consumption — typical consumption <2 W per channel, minimizing heat generation in the control panel
• DIN rail or panel mount — flexible installation options for control cabinets and marshalling panels

Performance Parameters

Material Composition

Structural Features

• Compact DIN-rail mountable module designed for installation inside control cabinets, marshalling panels, or junction boxes
• Front panel with LED indicators: Power (green), Channel 1 Fault (red), Channel 2 Fault (red), Signal Active (green)
• Front-panel DIP switches for configuring input/output signal type (4–20 mA, 0–20 mA, 0–10 VDC, 1–5 VDC)
• Rear terminal block array with clearly labeled connections for:
  • Safe area input (24 VDC supply and signal in)
  • Hazardous area output (signal out to field instruments)
  • Ground connection (chassis ground and IS ground)
• Hermetically sealed internal can — all magnetic coupling transformers, circuitry, and connections are enclosed in a laser-welded Kovar can, preventing any moisture or contaminant ingress
• Ventilation slots on top and bottom for natural convection cooling (no fan required)
• Surge protection devices (TVS diodes and MOVs) on all external connections
• EMC shielding via metal enclosure and filtered I/O connections
• IP65 front panel rating — protected against water jets and dust ingress from the front
• IP20 rear rating — rear terminals require enclosure protection
• Tamper-resistant terminal cover — hinged cover with gasket protects terminals from dust and accidental contact
• Label area — laser-etched identification on the enclosure face (model number, ratings, certifications)

Working Principle

1. The barrier receives a safe-area input signal (4–20 mA, 0–20 mA, 0–10 VDC, or 1–5 VDC) from the control system (DCS, PLC, or transmitter)
2. The input signal drives an oscillator circuit that generates a high-frequency AC signal (typically 50–100 kHz)
3. The AC signal is coupled across the isolation barrier via a magnetic transformer (galvanic isolation) — there is no electrical connection between input and output; energy is transferred via magnetic field
4. On the hazardous area output side, the AC signal is rectified and filtered to recreate the original DC signal (4–20 mA or voltage)
5. The output circuit includes energy-limiting components (resistors, zener diodes, fuses) that restrict the maximum voltage (Uo ≤ 30 VDC) and current (Io ≤ 100 mA for HO variant) to levels below the ignition threshold of the surrounding explosive atmosphere
6. The hermetic seal ensures that the internal components remain protected from humidity, dust, and chemical contamination, maintaining long-term calibration accuracy
7. The intrinsic safety principle guarantees that even under fault conditions (short circuit, open circuit, component failure), the energy delivered to the hazardous area remains below the minimum ignition energy (MIE) of the gas or dust present
8. The dual-channel design provides two independent isolated barriers in a single housing, each with its own input, output, and energy-limiting circuit

Advantages and Highlights

• Hermetically sealed construction — superior long-term stability compared to non-hermetic barriers; immune to humidity, dust, and chemical contamination
• High output current (100 mA per channel) — powers multiple field instruments from a single channel; eliminates need for local power supplies in hazardous areas
• Galvanic isolation — eliminates ground loops, provides noise immunity, and allows different ground potentials between safe and hazardous areas
• Intrinsic safety certified for IIC T6 — approved for the most hazardous gas atmospheres including hydrogen and acetylene
• Dual-channel in single housing — reduces panel space, wiring, and cost by 50% compared to two single-channel barriers
• Configurable signal types — supports 4–20 mA, 0–20 mA, 0–10 VDC, and 1–5 VDC via DIP switches
• Fail-safe by design — internal failure automatically limits energy to safe levels; no risk of ignition
• SIL 2 capable — meets IEC 61508 functional safety requirements for safety instrumented systems
• Wide supply voltage range (18–30 VDC) — compatible with most 24 VDC control systems
• Built-in diagnostics — per-channel LED indicators for power, fault, and signal status
• Low power consumption (<2 W per channel) — minimal heat generation in control panels
• ATEX, IECEx, FM, CSA, TIIS certified — globally approved for hazardous area use
• Long service life — hermetic seal prevents component degradation; MTBF >200,000 hours
• Compact form factor — fits in tight spaces on DIN rails and in control cabinets

Applicable Industries

Installation Requirements

Usage Precautions

• Never connect the barrier to a live circuit without verifying all wiring against the wiring diagram — incorrect connections will destroy the barrier and compromise intrinsic safety
• Verify cable capacitance and inductance before commissioning — total cable capacitance must not exceed 200 nF per channel; total inductance must not exceed 10 mH per channel
• Use only intrinsically safe rated cable for hazardous area connections — standard cable does not meet IS requirements and will void certification
• Do not exceed the rated output current of 100 mA per channel (HO variant) — overloading will destroy the energy-limiting components and compromise safety
• Do not bypass the built-in surge protection devices — external transients from lightning or switching will damage internal circuitry
• Allow 30 seconds warm-up time after initial power-on before expecting accurate signal transmission
• Do not adjust internal components unless qualified — incorrect settings cause calibration drift and loss of intrinsic safety certification
• Use shielded cable for all signal wiring in electrically noisy environments — unshielded cables near VFDs or welders cause false readings
• Ensure proper ventilation — do not install in a sealed enclosure without airflow; overheating above 60°C causes thermal shutdown
• Perform annual inspection of all terminal connections for tightness, corrosion, and wire insulation integrity
• Do not operate the barrier with the front cover removed — exposed terminals carry up to 30 VDC and 100 mA
• When replacing the unit, match the model number exactly — 8202-HO-IS is not interchangeable with 8201-LO-IS without reconfiguration
• Log all fault events using the built-in LED indicators or external SCADA for preventive maintenance
• Do not use the barrier with supply voltages exceeding 30 VDC — dielectric breakdown will occur and intrinsic safety will be lost
• For multi-channel operation, ensure each channel is independently fused on the safe-area side
• Do not mix IS cables with non-IS cables in the same tray — this creates a risk of energy transfer to non-IS equipment
• Store spare units in a dry, temperature-controlled environment (0°C to 40°C, <70% RH) with anti-static packaging
• Update firmware (if applicable) via MTL configuration software to the latest version for improved algorithms and bug fixes
• Do not modify the internal firmware or circuitry — only MTL-authorized personnel should perform modifications

Software and Configuration Tools

Key Parameters Summary (Bold Reference)