Types of Protection Devices

These are the types of various protection devices

• Circuit Breaker
• Fuse
• PolySwitch
• RCCB (Residual Current Circuit Breaker)
• Inrush Current Limiter
• Metal Oxide Varistor (MOV)
• Gas Discharge Tube (GDT)

Circuit Breaker

• Circuit breakers protect circuits from overloads and short circuits.
• These devices combine electrical and mechanical components together.
• Unusual current flow is sensed by a variety of detection mechanisms, such as electronic trip units or bimetallic strips.
• Circuit breakers trip to interrupt the circuit upon detection, shielding the equipment from harm.
• Both mechanical and electrical processes are involved in tripping mechanisms.
• Circuit breakers can be reset after tripping, unlike fuses.
• The ability to reset a device lowers downtime and replacement costs for blown fuses.
• Generally, circuit breakers increase the dependability and safety of electrical systems by offering effective, reusable protection.

Fuse

• Fuses are important safety components in electrical circuits preventing overcurrent situations.
• They consist of a thin metal wire or strip serving as a sacrifice.
• The wire melts when there is too much current flowing through it because of increased resistance.
• This melting closes the circuit, stopping the current flow and preventing damage.
• Fuses are one-time use items that need to be replaced after blowing.
• In order to restore power and resume regular operation, replacement is required.
• Fuse usage can result in downtime even though they provide simple and affordable protection.

PolySwitch

• Resettable fuses or PTC (Positive Temperature Coefficient) devices provide automatic reset functionality following the resolution of a fault condition.
• Consists of a polymer element with embedded conductive particles.
• The polymer keeps its resistance low during regular operation, enabling current flow.
• Heat produced during overcurrent events leads to the separation and migration of the conductive particles, increasing the resistance of the device.
• Elevated resistance restricts the flow of current, safeguarding linked elements.
• After the fault condition is resolved, the device cools down and the conductive particles reorganize to their initial state.
• By doing this, the device’s low resistance state is restored, permitting regular current flow.
• The requirement for manual intervention is eliminated by automatic resetting.

RCCB (Residual Current Circuit Breaker)

• Imbalanced current flow between live and neutral conductors is detected by RCCBs.
• Imbalances point to a possible leakage current that may be caused by unintentional paths.
• RCCBs detect something and immediately trip the circuit by means of a tripping mechanism.
• Mechanisms for tripping can be electrical or mechanical.
• By preventing electrical fires and electric shocks, RCCBs improve safety.
• In commercial, industrial, and residential settings, they are essential.
• Circuit breakers and RCCBs are frequently installed together for complete protection. Their extensive application emphasizes how crucial they are to improving electrical safety.

Inrush Current Limiter

• When electrical devices are turned on, inrush current happens, which can be harmful.
• Inrush current limiters  frequently use resistors or thermistors.
• When power is applied, these limiters momentarily increase resistance, which lowers the current surge.
• They gradually reduce resistance to permit regular current flow during normal operation.
• This protective measure guards against system failures and damage to electrical components.
• Frequently utilized in electronic devices, electric motors, and power supplies.
• Maintaining system longevity and dependability requires effective management of inrush current.

Metal Oxide Varistor (MOV)

• Here protection is provided against overvoltage conditions such as surges and spikes in voltage.
• Composed of ceramic material with metal oxide grains between two metal plates.
• During normal operation, acts as high impedance, allowing minimal current flow.
• When voltage spike occurs, MOV conducts electricity due to metal oxide grains.
• Creates low impedance path between metal plates, shunting excess voltage to ground.
• Prevents damage to connected devices by diverting excess energy.
• Used in power supplies, surge protectors, etc.
• Rapid response to voltage spikes ensures stability of electrical systems.

Gas Discharge Tube (GDT)

• They offer a low-impedance path to ground, protecting against an overvoltage spikes.
• They have two electrodes and a sealed container filled with inert gas.
• During normal operation, GDT presents high impedance, allowing minimal current flow.
• Voltage surge exceeding threshold ionizes gas, creating a conductive path.
• GDT rapidly transitions to low impedance, diverting surge energy to ground.
• Protects sensitive equipment by limiting voltage reaching them.
• After surge, gas reverts to non-conductive state, restoring high impedance.
• Commonly used in telecommunications, power distribution, and electronic devices.
• Quick response to voltage spikes ensures reliability of electrical systems.

In this article, we will be going through what are protection devices, we will start our article with the definitions of protection devices, we will see in short different types, then we will move to our Topic nature of protection devices, we will go through their working and Different types and See their Individual Working, at last, we will conclude our article with its advantages, disadvantages and Some FAQs.