Hybrid fiber cables are a type of fiber optic cable that combines multiple optical fibers and copper wires within the same jacket. The optical fibers handle high-speed data transfer, while the copper conductors are used for power delivery. They are commonly used in FTTH, FTTB and PON networks to power remote devices such as ONUs, Wi-Fi APs, small cells and IoT sensors.
Why Surge Protection Is Important?
However, hybrid fiber cables are vulnerable to electrical disturbances. Even though optical fibers themselves are immune to electromagnetic interference (EMI) and power surges, the copper conductors are not. A surge on the power line can instantly damage or destroy sensitive equipment.
Moreover, hybrid fiber cables are often deployed in FTTH, FTTB, PON and outdoor networks where cables run along poles, rooftops or underground. A lightning strike nearby, even without a direct hit, can induce high transient voltages on the copper conductors. Without surge protection, this energy flows straight into the connected device. In addition, sudden changes in the electrical network (e.g., when large loads are switched on/off, or during a power outage) can cause voltage spikes, stressing the insulation and overheating circuits.
That’s why you need a 100-240V AC optical power surge protector, a device designed to safeguard hybrid fiber cables from power surges, lightning strikes or switching transients.
What’s an AC Optical Power Surge Protector?
This is a surge protection device designed for Power over Fiber (PoF) systems, where power (AC, 100-240V) and data are carried together (or through related fibers/cables). Rated for 100-240V AC, it’s suitable for a wide range of electrical supply voltages. It protects against lightning-induced surges, switching spikes, and other voltage fluctuations that could damage the powered equipment. Key features include:
- Integrated LC connector for plug-and-play setup (no splicing or fusion needed).
- Built-in surge protection device (SPD) rated for 2.5 kV protection.
- Built-in fuse to prevent excessive current from reaching sensitive devices.
- Fast response time (< 25ns) to quickly shunt or suppress transients.
- Housed in a waterproof enclosure suitable for outdoor or harsh environmental conditions.
How It Works?
The surge protector is essentially invisible in normal operation, with low insertion loss on the fiber side and minimal resistance on the power side. When a surge occurs, it creates a sudden spike in voltage/current on the copper conductors and travels down the cable and can burn out sensitive electronics.
Inside the surge protector are components such as metal oxide varistors, gas discharge tubes or TVS diodes. They divert the excess energy to the ground through the protector’s earth wire. If the surge is extremely large or prolonged, the fuse blows and disconnects the circuit, sacrificing itself to protect the downstream equipment.
Once the surge subsides, the AC optical surge protector returns to its passive state. The optical fibers continue transmitting data normally, and the copper conductors resume supplying safe AC power.
How to Install the AC Optical Surge Protector?
Installing an AC optical surge protector is an effective method to protect your power over fiber (PoF) system from surges and electrical disturbances.
Apart from the 100-240V AC optical surge protector, you’ll also need:
- 8 Port Fiber Optic Switch: Include 8× 1G SFP ports and 2× 1G Ethernet ports.
- BiDi SFP Modules: Transmit and receive optical signals on a single fiber.
- 19” Power Distribution Rack: Equipped with a 120W industrial power supply and a circuit breaker to prevent electrical faults.
- DIN-Rail Hybrid Distribution Box: Include 12× LC adapters and 3× DC terminal blocks, standard 35mm DIN-rail mount.
- Power Surge Protector (optional): Support 2.5kV surge protection with a response time less than 25ns.
- Composite Fiber Cable: Carry both data and power over a single fiber cable. SMF, simplex LC, 2 fiber cores, 20AWG copper conductors.
- Outdoor PoE Fiber Media Converter: Convert optical signals to Ethernet and deliver up to 30 watts of power to the PoE device.
Step 1: Install the Power Distribution Rack
- Mount the power distribution rack (1U 19”) in the server or network cabinet.
- Connect the AC mains (100-240V) to the input terminals of the 120W industrial power supply. Connect the output terminal to one of the DC terminal blocks on the DIN-Rail hybrid distribution box.
- Connect the earth wire to the power supply chassis or grounding bus bar.
- Place the circuit breaker before the PSU and make sure it’s on the live line for AC. This ensures the breaker cuts power if there’s an overload or short circuit.
- For added reliability, you can also install a power surge protector on the AC mains line.
Step 2: Connect the SFP Switch
- Place the 8-port fiber optic switch in the control room and connect it to the mains.
- Insert a BiDi SFP module into one of the SFP slots in the switch and make sure it clicks into place.
- Connect a fiber optic cable from the SFP module to one of the LC adapters on the fiber distribution box.
Step 3: Run the Hybrid Fiber Cable
- If outdoors, use conduit or ducting to protect the cable from weather and rodents.
- Run the hybrid fiber cable from the power distribution box to the AC optical surge protector. Avoid sharp bends and do not exceed the cable’s maximum pulling tension.
- If your cable includes a dedicated earth/ground wire, connect it to the grounding point to divert excessive surges.
Step 4: Install the AC Optical Surge Protector
- Install the AC optical surge protector near the outdoor PoE fiber media converter.
- Wire the copper conductors from the hybrid fiber cable into the input terminals of the surge protector. Attach the protector’s ground wire to a proper earth ground.
- Connect the fiber strand to the LC adapter on the surge protector. Take care not to bend or stress the fibers during routing.
Step 5: Connect the PoE Fiber Media Converter
- From the surge protector’s output terminals, connect a short wire to the power input of the PoE fiber media converter.
- Insert a BiDi SFP module into the SFP port on the media converter and connect a fiber optic cable from the surge protector’s LC adapter to the SFP module.
- Plug one end of an Ethernet cable into the PoE output port of the media converter and connect the other end to the connected device, such as an IP camera, a Wi-Fi AP or a thin client.
Applications
The AC optical surge protector can be used in various applications, including:
Telecommunications & Networking
- Protect base stations, antennas, and repeaters from lightning and surge damage.
- Ensure stable operation of fiber-to-the-home (FTTH) or fiber-to-the-antenna (FTTA) systems.
Industrial & Harsh Environments
- Safeguard PoF systems used in factories, oil & gas plants, mining and energy facilities, where electrical noise and surges are common.
- Ideal for powering sensors, monitoring systems, and automation equipment in high EMI areas.
Smart Infrastructure
- Used in transportation networks (railways, highways, tunnels) where fiber carries both power and data to remote nodes.
- Protect security cameras, sensors, and communication devices installed outdoors.
Data Centers & Enterprise Networks
- Used to protect switches, servers, and edge devices from surge-related failures.
- Ensure uninterrupted data flow and power delivery in mission-critical services.
