Description
Eaton MTL7789+ Shunt-Diode Safety Barrier
Intrinsically Safe Hazard Zone Interface — 28V Martek Marine MM89 Compatible
This authentic Eaton MTL Instruments shunt-diode barrier is in excellent used condition. It has been pulled from a decommissioned, climate-controlled maritime monitoring panel, cleaned of dust, and inspected. All terminal clamping screws are in perfect working order with clean contact paths.
Product Overview
The Eaton MTL7789+ is an industry-standard, single-channel shunt-diode safety barrier engineered to provide intrinsic safety protection for electrical circuits running into explosive or volatile atmospheres. Crucially designed for hazardous gas and dust environments (Zone 0, 1, and 2), it blocks excess electrical energy from crossing from the safe-area control panel into the field sensors.
This specific model is widely utilized as a drop-in replacement barrier for **Martek Marine MM89** gas detection systems and bilge monitoring equipment. By limiting potential fault energy to completely safe, non-ignitable thresholds, the MTL7789+ guarantees comprehensive system safety compliance with international marine classification registries.
Technical Specifications
| Specification Parameter | Details |
|---|---|
| Brand / Manufacturer | Eaton (MTL Instruments) |
| Model Identifier | MTL7789+ (7789 Plus) |
| Safety System Lineage | Martek Marine MM89 Systems Integrated |
| Working Voltage (Un) | 26.2 V (Max Continuous working voltage) |
| Safety Parameters (Uo / Io) | 28 V / 93 mA |
| Channel Configuration | Single-Channel (Active Shunt Diode) |
| Safety Grounding | Direct grounding connection via integrated DIN-rail shoe |
| Mounting Profile | Standard 35mm T-section DIN-rail mounting |
Key Features
- Intrinsically Safe Barrier: Prevents any control equipment malfunction from sending spark-capable power levels down into dangerous maritime gas zones.
- Martek MM89 Drop-In: Pre-calibrated electrical impedance footprint makes it a direct, plug-and-play fitment for legacy and modern Martek Marine systems.
- Compact Ultra-Slim Profile: Features a high-density, side-by-side terminal arrangement, maximizing panel real estate inside congested electrical lockers.
- Fail-Safe Grounding Path: Dual grounding rivets on the DIN-rail anchor point provide redundant fault diversion directly to the ship’s copper ground bus.

