Hirschmann OZD Profi G12D repeater explosion-proof installation configuration

Hirschmann OZD Profi G12D Series PROFIBUS Fiber Optic Repeaters Explosion proof Installation and Ring Network Redundancy Configuration Guide

Introduction: Safe Crossing of Explosion proof Zones from Electrical to Optical Fiber

In environments with explosive gases or dust such as petrochemicals, pharmaceuticals, and gas transportation, PROFIBUS fieldbus networks must not only meet high-speed data transmission requirements, but also strictly comply with explosion-proof regulations. Traditional RS-485 electrical signals face inherent safety limitations and electromagnetic interference issues in Zone 1/21, while fiber optic transmission has become an ideal choice due to its electrical isolation and anti-interference advantages. The Hirschmann OZD Profi G12D series (including three variants of G12DU unprotected housing, G12DK plastic housing, and G12DE stainless steel housing) is a PROFIBUS fiber optic repeater designed for this purpose. It supports adaptive rates from 9.6kbit/s to 12Mbit/s and is ATEX/IECEx certified (Ex e mb op is [ib] IIC T4 Gb). It can be used as an electrical PROFIBUS signal to fiber optic network conversion interface in Zone 1, 2, 21, and 22. This article is based on the official manual, systematically reviewing the explosion-proof installation specifications, DIP switch mode configuration, fiber/electrical wiring, redundant ring network parameter calculation, and fault diagnosis methods of this series of repeaters, to assist engineers in safely and efficiently deploying PROFIBUS fiber networks in hazardous areas.

Chapter 1 Product Overview and Selection Analysis

1.1 Three shell variants and application scenarios

The core functionality of the OZD Profi G12D series is consistent - providing one electrical RS-485 channel (CH1) and two fiber optic channels (CH2, CH3), both supporting BFOC/2.5 (ST) connectors to achieve bidirectional conversion of electrical/optical signals. The difference lies in the form of the shell:

OZD Profi G12DU ATEX 1 (without protective casing): DIN rail installation (35mm) or flat installation, to be installed in the explosion-proof enclosure provided by the customer with IP54 or above, suitable for integration into existing control cabinets.

OZD Profi G12DK ATEX 1 (plastic shell): IP66 protection level, comes with cable sealing joints (PG glasses), can be directly installed in Zone 1/21 area (the shell itself is explosion-proof shell), optional transparent window cover (accessory OZD SFK ATEX) for easy observation of LED.

OZD Profi G12DE ATEX 1 (stainless steel housing): IP66, higher mechanical strength and corrosion resistance, suitable for harsh chemical or marine environments.

Selection key: If there is already an explosion-proof junction box on site, choosing G12DU has a lower cost; If independent outdoor installation is required, choose G12DK/G12DE. Stainless steel shell is more corrosion-resistant but heavier (about 3.7kg vs 2.4kg).

1.2 Interpretation of Explosion proof Markings

G12DU：II 2 G Ex e mb op is [ib] IIC T4 Gb

Ex e: increased safety terminal; MB: Sealed type; OP is: Optical isolation is inherently safe; [ib]: Associated with intrinsic safety circuits; IIC: Suitable for high-risk gases such as hydrogen and acetylene; T4: Maximum surface temperature ≤ 135 ° C.

G12DK/DE: II 2 G Ex e mb [ib] op is IIC T4 and II 2 D Ex tD A21 IP66 T130 ° C (dust explosion-proof).

Important restrictions: Maximum ambient temperature ≤ 60 ° C, pollution level 2, overvoltage category II. Only allowed to open the increased safety terminal cover in power-off state.

Chapter 2: Mandatory Regulations for Explosion proof Installation

2.1 Installation Requirements for Zone 1/21

G12DU: It must be installed in a casing that meets one of the following explosion-proof types: increased safety (e), explosion-proof (d), or enclosure protection (t), and the casing must be ATEX certified. The shell protection level should be at least IP54 (gas) or IP6X (conductive dust).

G12DK/DE: Can be installed directly, but all cable sealing joints must use certified models, and unused inlet ports must be sealed with certified plugs. The tightening torque should be executed according to the manual table (M16=2.5Nm, M20=3.5Nm, etc.), as over tightening or over loosening will damage the IP66 protection.

Live operation restrictions: In Zone 1, maintenance can be carried out while the shell cover is open (but the increased safety terminal cover cannot be opened). In Zone 21 (dust), the shell cover can only be opened after power failure or obtaining a "hot work permit". All terminal covers are strictly prohibited from being disassembled when live.

Dust deposition: The thickness of dust accumulation on the surface of the equipment shall not exceed 5mm (IEC/EN 61241-1).

2.2 Zone 2/22 Installation Requirements

Similar to Zone 1 but loose: the housing cover can be opened for maintenance while live (Zone 2), but Zone 22 still requires power off.

IP54 (gas) or IP6X (dust) requirements are the same as Zone 1.

2.3 Safety Zone Installation

G12DU can be directly installed in distribution cabinets located in safe areas (non explosion proof areas) without the need for additional enclosures. At this time, the shell cover can be opened at any time.