The MTL7700 Series of intrinsically safe passive network devices use zener diodes, resistors and fuses to safely divert excess electrical energy to ground and prevent sparking or overheating of equipment in hazardous areas.

The MTL7700 intrinsic safety device provides quick and easy installation and maintenance with removable terminals, the loop can be disconnect by simply unplugging the terminals from the side of the module. Wire entry is also angled to assist wiring within limited space enclosures.

DIN-rail mountable the MTL7700 intrinsic safety devices clamp simply and securely onto standard T-section DIN rail, simultaneously making a reliable intrinsically safe earth connection.

For applications where field device power is required for switch inputs or 2-wire transmitters, the MTL7700 barrier range provides a bussed power feed facility. When used in conjunction with the MTL7798 power feed module the user has a fully protected, electronically fused supply to many barriers with no additional wiring required.

All MTL7700 range zener barriers are based on the same simple principle. Each channel contains two stages of pulse-tested Zener or forward-connected diodes and an ’infallible’ terminating resistor. In the event of an electrical fault in the safe area, the diodes limit the voltage that can reach the hazardous area and the resistor limits the current. A fuse protects the diodes, and the two stages of voltage limitation ensure continued safety if either stage should fail. No active output current limiting circuits are employed. All models are certified ’ia’ for all zones and ’IIC’ for all explosive atmospheres (except MTL7707P+ and MTL7729P+, 'ia' 'IIB').

Intrinsically safe zener barriers
Standard DIN rail mount
Removable, colour-coded terminals
Bussed power feed to other modules
Solid state and relay switch modules
Choice of solid-state or relay output
Dual-channel variants - 6.3mm per channel
Proximity detector inputs
Direct replacement for MTL700 Series
Compatible terminal numbering and safety descriptions
Dimensions: 105 x 90 x 12.6mm

Power bus facility applicable to MTL7706+, 7741 and 7787+ barriers

BAS01 ATEX 7217

II 1 GD EEx ia IIC T6

This Eaton MTL zener barrier with analogue input reduces the risk of fire in your workplace. It reliably diverts the excess energy in equipment to the ground to prevent sparks and overheating that can lead to electrical fires. An innovative resistor and diodes limit the current and voltage going through to equipment in the event of electrical faults. This device provides a bussed power feed facility to equipment with switch inputs or 2-wire transmitters.

• Rigorous testing and certification means the intrinsic safety device meets the standard requirements for use in potentially explosive environments
• Removable terminals mean you can disconnect the loop by simply unplugging the terminals from the side of the module
• Angled wire entry makes wiring simple when space is limited
• Wide operating temperature range from -20°C to +60°C for use in demanding industrial applications

A zener barrier is a simple device that relays voltage and current into a defined hazardous area when there is a problem with the power supply. It creates an intrinsically safe earth to protect equipment and people.

Eaton formerly known as MTL