Hirschmann OZD Profi G12D repeater explosion-proof installation configuration

Chapter 3 Mechanical Installation and Grounding

3.1 DIN rail and flat installation

G12DU: The top buckle hangs on the 35mm guide rail and is locked by pressing down; Unlock with a screwdriver during disassembly. Alternatively, the rail adapter can be removed and installed flat using three M4 screws (see Figure 14 for drilling dimensions).

G12DK: Four semi-circular slots at the bottom, fixed to the plane with M4 screws (see Figure 16 for drilling dimensions).

G12DE: Two brackets at the bottom, fixed with M5 screws (see Figure 18 for drilling dimensions).

3.2 Functional Grounding (FG)

Important: The reference ground (FG) of the RS-485 interface is directly connected to the functional ground terminal without electrical isolation. Therefore:

The FG terminal must be connected to the equipotential grounding bar of the control cabinet.

If different control cabinets are connected through RS-485 cables, their grounding bars must be interconnected with low resistance.

It is strictly prohibited to lead RS-485 cables out of buildings (lightning protection), and optical fibers must be used to pass through building boundaries.

Wiring: The FG terminal of G12DU is located at the front single terminal (see Figure 24 in the manual); The FG terminal of G12DK/DE is located outside the housing (Figure 25) and requires a toothed washer to ensure good contact.

Chapter 4 Detailed Rules for Electrical and Fiber Optic Wiring

4.1 RS-485 Electrical Channel (CH1) Wiring

Terminals: DI A, DI B (receive input), DO A, DO B (send output). In practical use, A-A and B-B are usually short circuited to form a "loop in loop out" structure (as shown in Figure 22).

Shielding treatment: The cable shielding layer must be extensively connected to the equipotential busbar at the entrance of the control cabinet, and the shielding layer must be grounded at both ends (note that the potential difference may cause excessive shielding current, and equipotential compensation wires may be laid if necessary).

Terminal resistor: If the repeater is located at the end of the RS-485 bus segment, the internal terminal resistor needs to be connected through DIP switch S7 (OFF=connected, ON=disconnected).

Indoor wiring only: RS-485 cables shall not be laid outside buildings.

4.2 Fiber Channel (CH2/CH3) Wiring

Connector: BFOC/2.5 (ST), requiring cross connection (send receive, receive send).

Fiber type: multimode G 50/125 or G 62.5/125, wavelength 860nm, maximum segment length 3000m (attenuation budget: G50/125≤3.0dB/km，G62.5/125≤3.5dB/km）。

Wall sealing: The PG sealing joint of G12DK/DE is equipped with a slotted sealing ring, allowing the fiber optic cable pre installed with the connector to pass through (by breaking the sealing ring and fitting it onto the fiber optic cable).

Unused ports: must be sealed with protective caps to prevent environmental light interference and dust pollution.

4.3 Signal contact (relay) wiring

Terminals: F (common), FNC (normally closed), FNO (normally open). When there is no fault, F and FNC are conductive; When there is a malfunction or power outage, F and FNO are conductive.

Electrical limits: Maximum switching voltage 60V DC/42V AC, maximum current 1A, capacity 30W. SELV power supply must be used.

Reportable faults: fiber breakage, power loss, self-test error, ring network fault, etc. (indicated by LED and contacts simultaneously).

4.4 Redundant power supply

Terminal: Two independent 24V inputs (24V 1, 24V 2) and a 0V common terminal. Internal diode decoupling, automatic switching to higher voltage, no load balancing.

Voltage range: 18~32V DC (typical 24V), power consumption ≤ 5W.

Redundancy meaning: If the main power supply fails, the backup power supply will automatically take over, and the signal contacts will not be lost and trigger an alarm (requiring external monitoring).

Chapter 5 DIP Switch Working Mode Configuration

The front end of the device has 8-bit DIP switches (S0~S7, with S5/S6 having no function). The power must be disconnected before configuration.

5.1 Electrical Channel Mode (S0)

OFF (factory): Segment monitoring of electrical channels - detects error frames or continuous occupancy on RS-485, and blocks the channel if any abnormalities are found until normal operation is restored.

ON: Non segmented monitoring of electrical channels - only used in the electrical star segment of the star coupler to avoid accidental blocking.

5.2 Fiber Channel Mode (S1~S4)

Each optical channel is set independently, but the two optical channels must have the same mode (if both are used for ring, they must all be ring).

Mode S1/S3 S2/S4 Description

Line type OFF with fiber optic monitoring enables echo sending, echo monitoring, echo suppression, and segmentation functions

Line type ON/OFF without fiber optic monitoring only transparent forwarding, no fiber breakage detection (used to connect third-party devices that do not support echo)

Redundant halo ON Two optical channels form a ring network, which automatically switches to linear mode after fiber breakage

Important: The two ends of the optical channel (i.e. the corresponding optical ports of the two repeaters) must be set to the exact same mode, otherwise communication cannot be achieved.