KONGSBERG DZ-120 Zener Safety Barrier Unit

Core positioning and functions of the product

Product type: Single channel parallel diode Zener safety barrier unit, specially designed for Kongsberg brand instruments installed in hazardous areas.

Core function: Provide signal interface and power supply for instrument safety in hazardous areas, capable of connecting 4-20 mA intrinsic safety transmitters, and pre adapted to HART communication protocol.

Core value: As an electrical isolation device between safe and dangerous areas, it prevents safety accidents caused by excessive circuit energy in dangerous areas.

Working principle

Installation prerequisite: It must be installed in a safe area (such as a control room) to protect the 2-wire 4-20 mA/HART signal transmitter in hazardous areas.

Protection mechanism:

When a fault voltage occurs at the safety side terminal, the Zener diode limits the voltage that may occur in the hazardous area, and the resistor limits the current to a safe and acceptable value;

Allow short circuits in connecting cables within hazardous areas without posing any safety risks.

Installation requirements and specifications

The installation of DZ-120 must strictly follow the requirements of intrinsic safety and explosion-proof. The core installation rules and wiring specifications are as follows, which are indispensable:

Installation position and method: Typically installed in the control room processing cabinet, it adopts TS-35 guide rail (in accordance with DIN46277 standard) snap on installation, and requires the use of end plugs to support the equipment.

Definition of wiring terminals:

T4, T5 (blue terminals): Connect intrinsically safe circuits in hazardous areas;

T2, T3: Analog input channels connected to the monitoring system;

T6: The grounding terminal needs to be connected to the intrinsic safety busbar of the system.

Grounding requirements

The equipment needs to be grounded to the system’s intrinsic safety busbar through a minimum of 1.5 mm ² cable;

The intrinsic safety side of the safety barrier must be equipped with a dedicated grounding/grounding plate, and the 3rd and/or 6th terminals of each safety barrier must be connected to the grounding plate through a cable of ≥ 1.5 mm ².

Special conditions for safe installation

① During the final installation in the cabinet, a minimum separation distance of 50 mm should be maintained between intrinsic safety circuits and non intrinsic safety circuits;

② The equipment must be installed in a cabinet with a protection level of at least IP22;

③ The operating temperature range of the equipment is * * -20 ° C ≤ Ta ≤+70 ° C * *;

④ The humidity requirement is a maximum of 75% and there is no condensation.

Safety instructions: For detailed safety operation requirements, please refer to document 373874 K-Gauge Ex I Safety Instructions.

Core product features

Realize intrinsic safety electrical connection of 4-20 mA transmitters from hazardous areas to safe areas, with native support for HART communication;

Adopting DIN rail buckle installation, easy to install without the need for additional fasteners;

Compact in size and lightweight, weighing only 0.1kg, saving cabinet installation space;

Approved by ATEX, IECEx explosion-proof certification, and type certification from multiple classification societies, in compliance with maritime industry standards;

Single channel design, specifically designed for 2-wire transmitters, with strong targeted functionality.

Key technical specifications

The core specifications of DZ-120, including electrical, physical, intrinsic safety and explosion-proof, have clear standards. The core parameters are shown in the table below, and unmarked units are default industry units:

Specification category specific parameters

Power supply nominal 24 VDC (± 0.5 V)

The nominal resistance parameter is 265 Ω; Maximum series resistance 270 Ω; Maximum load resistance 150 Ω

Fuse specification 50 mA

Signal interface 4-20 mA/HART

Temperature range: -20 ° C~+70 ° C; Storage: -25 ° C~+70 ° C

Physical dimensions: 12.5 × 114.5 × 99.0 mm (width × height × depth); Weight: 0.1 kg; Terminal specification: 2.5 mm ²; Equipment protection level: IP20

Relative humidity of environmental parameters: ≤ 75% (no condensation); Compliant with IACS E10 and CISPR 22 environmental standards

The maximum safe voltage of intrinsic safety parameters is Um=250 VAC; Output Uo=26.5 VDC, Io=112 mA, Po=0.74 W; Maximum external capacitance Co=95 nF; Maximum external inductance Lo=2.8 mH; Lo/Ro=48 µH/Ω

Certification standards

Explosion-proof certification

Explosion proof grade: II (1) G [Ex ia Ga] IIC;

ATEX Directive: 2014/34/EU, certification number Presafe 16 ATEX 7965;

IECEx certification: Number IECEx PRE 16.0020;

Explosion proof standards: EN 60079-0:2012, EN 60079-11:2012, IEC 60079-0:2011, IEC 60079-11:2011.

Classification society type certification: ABS, BV, CCS, DNV-GL, KRS, LRS, NK, Rina (covering mainstream maritime classification certifications worldwide).