Pepperl+Fuchs Z755 Zener Barrier

The Pepperl+Fuchs Z755 is a single-channel Zener barrier designed for intrinsically safe (IS) applications, providing protection for 4-20 mA analog signals in hazardous areas classified under Zone 1/21 and Zone 2/22. It ensures safe signal transmission between field devices (e.g., transmitters) and control systems by limiting voltage and current to non-incendive levels.

Key Features of the Z755 Zener Barrier

✔ Analog Signal Protection – Designed for 4-20 mA current loops

✔ Intrinsic Safety Certifications:

ATEX/IECEx (Ex ia IIC T6 Ga / Ex ib IIC T6 Gb)

FM/CSA (Class I, II, III, Div. 1)

✔ Electrical Specifications:

Supply Voltage: 8-30V DC

Max. Output Voltage (Uo): 28V DC

Max. Output Current (Io): 93 mA

✔ LED Status Indicator – Visual power/fault monitoring

✔ Compact Design – DIN-rail mountable (35mm rail)

Typical Applications

Process automation (pressure/flow/temperature transmitters)

Oil & gas facilities

Chemical plants

Pharmaceutical production

Wiring & Installation

Safe Area (Control Side)

Terminal 1 (+Ub): Power supply (8-30V DC)

Terminal 2 (GND): Critical earth ground (<1Ω required)

Terminal 3 (OUT): Signal to PLC/DCS

Hazardous Area (Field Side)

Terminal 4 (IS+): To field device

Terminal 5 (IS-): Return line

⚠ Important Safety Notes:

Proper grounding is mandatory for safe operation

Not suitable for Zone 0 unless Ex ia certified

Maximum field device load: ≤93 mA

Comparison with Similar Barriers

Model Type Key Difference

Z755 Analog Zener Barrier 4-20 mA signals

Z715 Digital Zener Barrier ON/OFF signals

KFD2-SR2-Ex2 Galvanic Isolator No ground needed

Why Choose the Z755?

✅ Cost-effective IS protection for analog signals

✅ Globally certified for hazardous areas

✅ Simple installation (DIN-rail mounting)