Regular inspection and replacement of SPDs, especially after significant surges, are essential to maintaining effectiveness.
About SPD
What is a Surge?
A power surge is a sudden and temporary increase in voltage, typically lasting only a fraction of a second, but with the potential to cause significant damage to electronic devices and electrical systems.
Surge voltages act in two directions in affected circuits:
Common-mode voltages [UL] occur in the event of interference caused by surge voltages or high-frequency interference voltages between active conductors and ground. The term asymmetrical is also often used.
Asymmetrical voltages primarily endanger components that are located between active potentials and a grounded ground, as well as the insulation between active potentials and ground. This results in sparkovers on PCBs or between voltage-carrying equipment and grounded housing parts.
Normal-mode voltages [UQ] occur in the event of interference caused by surge voltages or high-frequency interference voltages between the active conductors of a circuit. The terms symmetrical and differential-mode are also used.
Symmetrical surge voltages endanger the voltage and signal input of devices and interfaces. This results in direct overload and destruction of the affected equipment, e.g., in the power supply or signal-processing components.
Common Causes of Surges in Electrical Devices
Lightning strikes
One of the most common causes of power surges is lightning strikes. When lightning hits a power line or utility equipment, it can send a surge of electricity through the electrical system
Electrical overload
An electrical overload happens when a circuit is asked to handle more electrical current or power than it can safely manage, causing a surge in voltage.
Power grid disturbances or outage
Problems within the electrical grid, such as transformer malfunctions or switching operations, can lead to voltage spikes.
Faulty wires or equipment
Electrical faults or short circuits within a building's wiring can generate power surges.
Utility Company Operations
Activities like power restoration after an outage or maintenance work by the utility company can sometimes result in voltage fluctuations.
Appliance Usage
Some appliances, particularly those with high-power requirements like air conditioners or refrigerators, can cause small power surges when they cycle on and off. A power surge can also occur by switching on & off an appliance such as an air conditioner (ac), a refrigerator or even a television if there is no proper earthing.
What can be Affected by a Power Surge
A power surge can affect mostly all types of electrical and electronic devices and systems
Laptops and Servers
Power surges can damage computer components, including the motherboard, hard drive, and power supply, potentially leading to data loss or system failure.
Home Entertainment Systems
TVs, especially modern flat-screen models, music systems, are susceptible to power surge damage. This also includes DVD players, gaming consoles, audio systems, and streaming devices. Surges can disrupt functionality, cause permanent damage, harm internal circuitry and display screens.
Kitchen Appliances
Refrigerators, microwaves, ovens, and other kitchen appliances with electronic controls can experience damage during power surges.
HVAC Systems
Heating, ventilation, and air conditioning systems with electronic components may suffer from surge-related issues.
Washers and Dryers
Modern washing machines and dryers often have electronic controls that can be affected by surges.
Home Security Systems
Surveillance cameras, alarms, and access control systems can be damaged or rendered nonfunctional by power surges.
Modems and Routers
Networking equipment can be sensitive to surges, potentially disrupting internet connectivity.
Smartphones and Tablets
Chargers and USB ports can be vulnerable to power surges when devices are charging.
Home Office Equipment
Printers, scanners, and fax machines may experience damage from power surges.
Lighting Systems
LED and smart lighting systems can be affected, leading to flickering or damage.
Electrical Wiring
Repeated power surges can wear down electrical wiring, potentially causing safety hazards.
Industrial Equipment
In industrial settings, machinery with electronic controls and automation systems can be at risk.
Medical Equipment
Hospitals and healthcare facilities must protect sensitive medical equipment from surges to ensure patient safety.
Power Distribution Systems
Surges can affect the entire electrical distribution system of a building or facility, potentially damaging transformers, circuit breakers, and switchgear.
To protect against power surges, surge protection devices (SPDs) or uninterruptible power supplies (UPS) are commonly used for sensitive equipment. Whole-house or facility surge protection systems can also be installed at the electrical panel to safeguard the entire building or facility.
A power surge can cause overheating, short-circuiting, heat expansion, and can cause even a permanent damage to a part/parts or the entire device. A power surge can even blow out light bulbs.
Improperly installed surge protection devices increases the liability risks for installers of switching devices.
Long connecting cables to the SPDs can cause malfunctions, potentially leading to dangerous sparking and even fires.
Types of Surge Protection Devices:
Surge Protection Devices (SPDs) come in various types to protect electrical and electronic systems from voltage surges and transient events. The main types of SPDs include:
Type 1 SPD (or Class I SPD)
Installed at the main electrical panel, they protect against direct lightning strikes or large power surges entering a building. They handle high-energy waves and are the first line of defense in a comprehensive surge protection strategy.
Type 2 SPD (or Class II SPD)
Installed at the sub-distribution boards, Type 2 SPDs provide protection against moderate surges and are essential for safeguarding individual devices or equipment.
Type 3 SPD (or Class III SPD)
Often integrated into personal devices, Type 3 SPDs offer localised protection against low-energy surges. They're typically used for protecting sensitive electronics.
Type 4 SPD (or Class IV SPD)
These SPDs are designed for specific electronic devices and appliances. They offer protection against low-energy, internally generated surges and are often built into the devices they protect.
Gas Discharge Tubes (GDTs)
GDTs are fast-acting SPDs that discharge excess voltage by ionizing a gas, creating a low-resistance path to the ground.
Metal Oxide Varistors (MOVs)
MOVs are semiconductor components with high resistance under normal conditions but rapidly become conductive when voltage exceeds a certain threshold, providing a path to the ground.
Carbon Varistors
Similar to MOVs, carbon varistors are made of carbon-based materials. They exhibit a nonlinear current-voltage characteristic, providing surge protection.
Silicon Avalanche Diodes (SADs)
SADs are semiconductors that conduct when the voltage across them exceeds a certain level. They are fast-acting and effective for surge protection.
The choice of SPD depends on the specific application and the level of protection required against transient voltage events. Different SPDs are used at various points within an electrical system to ensure comprehensive protection against surges.
How Surge Protection Devices (SPDs) Work
An SPD restricts the voltage supplied to an electrical device such that voltage supply does not exceed the safe operating range.
During a surge, the SPD provides a low-resistance path to divert the excess current to the ground, bypassing the connected devices.
Advantages of Surge Protection Devices (SPDs)
Equipment Protection
SPDs prevent damage to electronic devices, appliances, and other equipment, saving on repair and replacement costs.
Increased Lifespan
By safeguarding devices from surges, SPDs extend the operational life of electronics and reduce the frequency of replacements.
Data Protection
For systems involving data storage or transmission, SPDs protect against surges that could corrupt or destroy important data.
Safety
Protects against electrical fires and hazards, enhancing overall safety in residential, commercial, and industrial environments.
Equipment Protection
SPDs prevent damage to electronic devices, appliances, and other equipment, saving on repair and replacement costs.
Increased Lifespan
By safeguarding devices from surges, SPDs extend the operational life of electronics and reduce the frequency of replacements.
Data Protection
For systems involving data storage or transmission, SPDs protect against surges that could corrupt or destroy important data.
Safety
Protects against electrical fires and hazards, enhancing overall safety in residential, commercial, and industrial environments.
Surge Protection Devices (SPD) are indispensable for safeguarding our electronic infrastructure against unpredictable power surges. By investing in quality SPDs and integrating them into electrical systems, businesses and individuals can ensure the longevity and reliability of their electronic devices, thus minimising downtime, reducing repair costs, and enhancing overall safety.
Considerations for Installation of an SPD
SPDs should be strategically placed at entry points where electrical power, data, or communication lines enter a building or a device.
It’s crucial to ensure that SPDs meet relevant standards and regulations to guarantee their effectiveness and safety.
