Eaton MTL7767+ 2-Channel 12V DC Safety Barrier ATEX Certified for Hazardous Areas
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negotiable
MOQ:
1
Delivery Time:
In stock
Brand:
MTL
Product Description
Eaton MTL MTL7767+ 7700 Series Relay Contact Safety Barrier ATEX Certified Hazardous Area
Product Overview
The MTL7767+ is a high-performance 2-channel shunt-diode safety barrier (Zener barrier) from Eaton's Crouse-Hinds series MTL7700 range, specifically engineered for positive DC systems up to 12V DC requiring intrinsic safety protection in hazardous areas.
This passive device limits the voltage and current that can reach a hazardous area under fault conditions, preventing ignition of flammable atmospheres. With a safety description of 15V, 100 Ω, 150mA, the MTL7767+ is the ideal solution for protecting low-level DC circuits in Zone 0, 1, and 2 hazardous locations (gas groups IIC, IIB, IIA).
Model Number Decoding
| Code Segment | Meaning |
|---|---|
| MTL | MTL Instruments Group (now Eaton) |
| 77 | MTL7700 series — Shunt-diode safety barriers |
| 67 | Specific barrier configuration for low-level positive DC systems |
| + | Positive polarity configuration |
Key Features & Benefits
- 2-Channel Efficiency: Two independent intrinsically safe channels in a single compact housing — protects two field devices while using minimal panel space
- Low Voltage DC Optimization: Specifically designed for positive DC systems up to 12V DC — ideal for low-level logic circuits and digital inputs
- 15V Safety Description: Provides safe voltage limiting for low-voltage DC circuits, preventing ignition under fault conditions
- 100 Ω End-to-End Resistance: Low resistance design minimizes voltage drop in sensitive low-voltage circuits
- 150mA Maximum Current: High current capability suitable for switching applications and low-power loads
- IIC Gas Group Certification: Certified for use in the most hazardous gas groups including IIC (hydrogen, acetylene)
- Removable Terminals: Unique removable terminal blocks for easy cabling, maintenance, and loop disconnect by simply unplugging terminals from the side of the module
- Bussed Power Capability: Reduces cabling requirements with integrated bussed power distribution — a unique feature of the MTL7700 series
- Angled Wire Entry: Wire entry is angled to assist wiring within limited space enclosures
- Ultra-Slim DIN Rail Mounting: Compact 12 mm width for standard 35 mm DIN rail installation — simultaneously makes a reliable IS earth connection when clipped onto the rail
- Dual-Stage Protection: Two stages of pulse-tested Zener diodes and an 'infallible' terminating resistor ensure continued safety if either stage should fail
- No Active Current Limiting Circuits: Pure passive design for maximum reliability — no active output current limiting circuits are employed
Technical Specifications
General Specifications
| Parameter | Value |
|---|---|
| Manufacturer | Eaton (Crouse-Hinds series MTL) |
| Series | MTL7700 Range |
| Product Model | MTL7767+ |
| Product Type | Shunt-Diode Safety Barrier (Zener Barrier) |
| Number of Channels | 2 (dual-channel) |
| Polarity | Positive (+) |
Electrical Ratings
| Parameter | Value |
|---|---|
| Safety Description | 15V, 100Ω, 150mA |
| Working Voltage (Vwkg) | 12V DC nominal (low-level DC systems) |
| End-to-End Resistance | 110Ω Min to 119Ω Max |
| Maximum Current | 150mA |
Hazardous Area Specifications
| Parameter | Value |
|---|---|
| Gas Groups | IIC, IIB, IIA |
| Zones | Zone 0, 1, 2 |
| Equipment Protection Level (EPL) | Ga, Gb, Gc |
| Certification | ATEX II (1) GD [Ex ia] IIC |
Mechanical Specifications
| Parameter | Value |
|---|---|
| Width | 12 mm |
| Height | 85 mm / 90 mm |
| Depth | 105 mm |
| Weight | 0.120 kg / 120 g |
| Enclosure Material | Polycarbonate |
| Mounting | DIN rail (35 mm T-section) |
| Terminals | Removable screw terminals |
Function Description
The MTL7767+ is a passive shunt-diode safety barrier that operates on the Zener barrier principle. It limits both voltage and current that can be delivered to a hazardous area circuit under fault conditions.
How it Works:
- Voltage limiting: Zener diodes clamp the output voltage to a safe level (15V) if the safe-area voltage rises above normal operating levels
- Current limiting: A series resistor (100Ω) limits fault current to a safe value (150mA)
- Fusing: Internal fuses provide backup protection under severe fault conditions
- Two-stage voltage limitation: Two stages of pulse-tested Zener diodes ensure continued safety if either stage should fail
- No active output current limiting circuits: Pure passive design for maximum reliability
- Grounding: The barrier requires a connection to a high-integrity earth ground — made simultaneously when clipping onto standard T-section DIN rail
Safe Area (Control Side) Hazardous Area (Field Side)
PLC/DCS/Indicator ──► MTL7767+ ────► Intrinsically safe circuit
12V DC supply ──► (Voltage/Current limiting) ──► Low-level DC sensors/switches
(Zener diodes + 100Ω resistor)
[High-integrity earth ground required]
Applications
The MTL7767+ is specifically designed for positive DC system protection in hazardous area installations:
| Industry | Application |
|---|---|
| Oil & Gas | Low-level DC logic circuits and sensor inputs on offshore platforms and refineries |
| Chemical Processing | 12V DC control circuits, digital input protection in explosive atmospheres |
| Pharmaceutical | Low-voltage DC systems for batch processing equipment requiring Ex protection |
| Factory Automation | 12V DC proximity sensors, limit switches, and digital I/O protection |
| Power Generation | Turbine control systems with low-level DC inputs |
| Marine & Offshore | Marine control systems requiring intrinsic safety certification |
Typical Field Devices Connected:
- 12V DC proximity sensors
- Low-level DC switches and push buttons
- Digital input circuits in hazardous areas
- LED indicators
- Simple apparatus (switches, thermocouples, resistive sensors, photocells)
MTL7767+ vs. Related MTL7700 Series Models
| Model | Channels | Working Voltage | Resistance | Current | Polarity | Primary Application |
|---|---|---|---|---|---|---|
| MTL7767+ | 2 | 12V | 100 Ω | 150mA | Positive (+) | 12V DC positive systems |
| MTL7764+ | 2 | 12V | 1,000Ω | 12mA | Positive (+) | Strain-gauge bridges |
| MTL7722+ | 2 | 18V | -- | -- | Positive (+) | 18V DC systems |
| MTL7706+ | 1 | 28V | 300Ω | 93mA | Positive (+) | General purpose positive polarity |
Installation Information
| Parameter | Detail |
|---|---|
| Mounting | Standard 35 mm T-section DIN rail (EN 60715) |
| Terminals | Removable screw terminals |
| Grounding | High-integrity earth connection made simultaneously when clipping onto DIN rail |
| Wire Entry | Angled to assist wiring in limited space enclosures |
| Clearance | Minimal — 12 mm width enables high-density installation |
| Operating Position | Any orientation |
Important Installation Notes:
- A high-integrity earth ground connection is mandatory for proper Zener barrier operation
- Do not install in areas where condensation may occur
- The barrier must be installed in a safe area (non-hazardous location)
- The MTL7767+ and MTL7764+ can be safely used together in IIC environments
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Company
Shenzhen Hengyo Power Technology Co., Limited
Location
Room 2407, B Block No.145 Chengshi Zhuchang Bld, Bagua 2nd Rd, Futian Dist. Shenzhen City, China 518029
Contact Person
Vivian Chan