EATON MTL MTL7796 Safety Barrier

Product Description

MTL7796 (EATON MTL) is a negative-polarity zener intrinsically safe barrier in MTL7700 series, DIN rail mounted, specially designed for 3-wire vibration transmitters powered by -24V DC. It adopts shunt diode voltage limiting, current-limiting resistor and fuse protection with two-stage voltage limiting design. It limits the energy transferred from safe side to hazardous area to avoid ignition of flammable gas and provide intrinsic safety protection. It isolates signals between safe and hazardous area without disturbing vibration signal transmission, suitable for probe signal loop of TSI vibration monitoring system. Equipped with removable terminals for easy wiring and requires reliable intrinsic safety earthing. Explosion protection mark Ex ia Ga IIC.

Specifications

• Model: MTL7796
• Brand: EATON MTL
• Type: Zener intrinsically safe barrier (negative polarity)
• Ex Marking: Ex ia Ga IIC
• Max continuous voltage at safe side Um: 250V
• Open circuit voltage Uo (hazardous side): 26V
• Short circuit current Io (hazardous side): 87mA
• Max permitted power Po: 0.56W
• Max internal capacitance Ci: 0.81μF
• Max internal inductance Li: 0.1mH
• Recommended Supply: -24V DC for 3-wire vibration transmitters
• Power Dissipation: approx. 0.6W @24V
• Terminals: Removable plug terminals, max wire size 2.5mm²
• Mounting: Standard 35mm DIN rail
• Operating Temperature: -20℃ ~ +60℃
• Storage Temperature: -40℃ ~ +80℃
• Relative Humidity: 5%~95%, non-condensing
• Weight: approx. 140g
• Certifications: ATEX, IECEx, CE, NEPSI
• Features: Two-stage voltage limiting, passive zener barrier, dedicated for vibration monitoring loops, requires reliable IS earth connection

Application

It is mainly matched with 3-wire vibration transmitters / velocity sensors for TSI vibration monitoring systems such as EPRO and Bently Nevada. Widely used in hazardous areas of petrochemical, gas, power plants. Installed inside control cabinet in safe area, wired between vibration probes in hazardous zone and monitoring modules. It limits fault energy for intrinsic safety protection and transmits vibration analog signals, protecting field sensors. Applied on vibration monitoring & explosion-proof loops for steam turbines, compressors, fans and other rotating machinery.

Series Models (MTL7700 Zener Barrier Series)

1. MTL7796: Negative polarity zener barrier for 3-wire vibration transmitter (-24V)
2. MTL7796+: Positive polarity zener barrier for 3-wire vibration transmitter (+24V)
3. MTL7706+: 2-wire 4-20mA transmitter, high level analog input
4. MTL7787+: 2-wire conventional / smart 4-20mA transmitters
5. MTL7755ac: Non-polarised barrier for thermocouple / mV signals
6. MTL7760ac: Low level thermocouple & mV signal barrier
7. MTL7728+: Analog output zener barrier