Surge Protection Devices

Surge Protection Devices (SPDs) are essential for safeguarding electrical installations from dangerous power surges, known as transient overvoltages. These current spikes can inflict significant damage to equipment and pose serious safety hazards, therefore requiring robust protection.

To counter a wide array of threats, surge protection devices come in diverse designs, from 240V protectors to robust 3-phase units. This allows them to effectively protect vital assets such as sensitive electronics and machinery across Australia, ensuring safe and uninterrupted operation.

What Are Surge Protection Devices Used For?

Surge protection devices are specifically deployed to manage and mitigate electrical threats across diverse industrial applications. These surge protectors function as suppressors, defending against internal voltage spikes in electrical panels and industrial systems. Additionally, they also serve as arresters, shielding machinery from external occurrences like lightning strikes, ultimately ensuring overall system stability.

How Surge Protection Devices (SPD) Work

Surge protection devices function as voltage-controlled switches, installed in parallel with electrical equipment. During a surge, these surge limiters instantly switch from high to near-zero impedance, diverting excess current to the ground. This channels the dangerous overvoltage away from downstream equipment, preventing any electrical damage.

3-Phase Surge Protectors: 3-Pole and 4-Pole Devices

3-phase DIN rail surge protectors are crucial for safeguarding electrical systems, with 3-pole and 4-pole configurations offering specific protection based on network wiring. Here’s a breakdown of their key features:

• 3-Pole Devices:
  • Protection Scope: These surge protection devices safeguard electrical equipment connected to 3-phase power distribution panels. They protect active conductors from damaging transient overvoltages.
  • System Compatibility: They are typically used in 3-phase systems like TN-C-S wiring, where the neutral conductor is earthed close to the main switchboard, simplifying the earthing path.
  • Installation Scenarios: They are installed within 10 meters of the main earthing link, where a dedicated neutral-to-earth (N-PE) path is not required directly through the SPD.
• 4-Pole Devices:
  • Protection Scope: 4-pole surge protectors safeguard sensitive electrical equipment in 3-phase power distribution and downstream systems from overvoltage surges.
  • System Compatibility: These devices are typically used in TN-S and TT wiring systems. They are also required for TN-C-S systems when the SPD is installed further from the main earthing point.
  • Installation Scenarios: A 4-pole 3-phase surge protector is required beyond 10 meters from the main earthing link, as increased impedance necessitates an additional N-PE pole for comprehensive protection.

Classification of Surge Protectors

Surge protection devices are classified by their discharge capacity and intended protection level, according to international standards. Here are the three types:

Type 1 Surge Protectors

Type 1 surge protectors are designed to discharge very high currents from direct lightning strikes. Tested with a 10/350 μs waveform, they are installed at the main service entrance or incoming power supply panels. This type also often comprises specialised secondary surge arresters, crucial for buildings with external lightning protection.

Type 2 Surge Protectors

Type 2 surge protectors handle high currents from indirect lightning strikes or switching events. Tested with an 8/20 μs waveform, they are typically installed in distribution panels. This category includes devices such as branch surge panels, which offer robust protection against internally generated surges and external transients, commonly placed downstream of Type 1 units.

Type 3 Surge Protectors

Type 3 surge protectors offer fine protection for sensitive equipment, typically installed downstream from Type 2 devices. Tested with a combined 1.2/50 μs - 8/20 μs waveform, they discharge medium currents. Some common examples include surge protector plugs and surge protection modules, serving as vital point-of-use defenses against overvoltage spikes.

SPD Features Based on the IEC 61643 Standard

Surge protection devices possess key electrical parameters defined by the IEC 61643 standard, vital for selecting the appropriate protector for your needs. These include:

• Up (Level of Protection): This parameter denotes the maximum residual voltage allowed to pass through the surge protection device. A lower Up value signifies better protection for downstream equipment.
• **In (Nominal Current): **This represents the peak current (8/20 μs waveform) a surge protector can withstand 20 times. It signifies the device’s robustness under repetitive surges.
• Imax (Maximum Discharge Current): The Imax indicates the maximum single peak current (8/20 μs waveform) a surge protector can discharge once without failing. It defines the device’s ultimate capacity for extreme surge events.
• Uc (Maximum Continuous Operating Voltage): This is the highest effective voltage that can be applied permanently to the terminals of the surge protection device without it activating. It defines the device’s continuous operational threshold.
• Iimp (Impulse Current): This parameter indicates the peak current (10/350 μs waveform) a surge protector can withstand. It is particularly relevant for Type 1 devices that protect against direct lightning strikes.

Industrial Applications of Surge Protection Devices

Surge protection devices are vital for ensuring industrial workplace safety and reliability across a multitude of sectors, protecting critical electrical systems. These include:

Power Generation and Distribution

In power plants, substations and utility networks, surge protection devices are critical. They safeguard sensitive equipment and control systems from high-energy transients caused by lightning strikes or grid switching, ensuring power grid stability and continuous supply.

Manufacturing and Automation

Industrial surge protection is indispensable in manufacturing facilities and automated plants. It protects sensitive control panels, PLCs and robotic systems from voltage spikes and internally generated surges, ensuring seamless production and maximising operational uptime.

Data Centres and Telecommunications

These sectors demand uninterrupted operation, making surge protection devices essential for servers, networking equipment and communication lines. They protect against both externally and internally generated surges, safeguarding critical data and ensuring continuous service availability.

Commercial and Public Infrastructure

Public infrastructure like hospitals, airports and banking institutions rely heavily on robust surge protectors. They shield life-support systems, air traffic control and financial networks from electrical disruptions, ensuring critical services remain operational and secure.

Do You Need Surge Protection in Australia?

Yes, surge protection is highly recommended in Australia due to the constant threat of transient overvoltages from various sources. These damaging surges can originate from lightning strikes, utility grid switching or even internal electrical operations like motor disconnections. Such unpredictable energy spikes can cause premature aging, equipment failure and significant financial losses across power, communication and data lines.

For residential and commercial buildings, a whole house surge protector strategy is highly recommended, involving a cascaded approach with multiple protection stages. This typically includes surge protection devices at the main service entrance, distribution boards and point-of-use outlets, ensuring all vital assets are shielded.

Buy Electrical Surge Protection Devices Online from RS Australia

RS Australia is your trusted manufacturer and distributor of high-quality electrical surge protection devices. Our catalogue showcases a wide selection of surge protection devices — as well as associated products such as circuit breakers and electrical enclosures — from leading manufacturers like Phoenix Contact and Schneider Electric. All our products undergo rigorous testing, comply with international standards and are backed by our commitment to assured quality.

For the utmost convenience, RS Australia also provides the rapid, nationwide doorstep delivery of all your orders. For more information regarding dispatch timelines, applicable charges and available shipping choices, please consult our dedicated Delivery Information page today!