Free Expert Guides on Power Systems, Circuit Design & Electrical Troubleshooting

How to Calculate Short Circuit Current?Short Circuit Current DefinitionShort circuit current is defined as the large current that flows through an electrical system when a fault occurs, causing potential damage to circuit breaker components.When a short circuit fault happens, a large current flows through the system, including the circuit breaker (CB). This flow, unless stopped by the CB tripping, subjects the CB parts to significant mechanical and thermal stresses.If the CB’s conducting parts l

Circuit Breaker DefinitionA circuit breaker is defined as a device that opens and closes electrical contacts to protect circuits from faults.Therefore, circuit breakers must operate reliably without any delay. To ensure this reliability, the operating mechanism is more complex than it first appears. The distance and speed of the moving contacts during opening and closing are crucial design parameters for circuit breakers.Contact gap, traveling distance of moving contacts and their velocity are d

Definition of Routine TestsRoutine tests are regular evaluations conducted to ensure the quality and performance of circuit breakers.Power Frequency Over Voltage TestThis test checks if circuit breakers can handle unexpected high voltage conditions.Dielectric TestPower system can experience temporary overvoltage conditions due to various reasons, like sudden load changes or incorrect tap changer operations. The power frequency over voltage withstand test checks if a circuit breaker’s insulation

Circuit Breaker DefinitionA circuit breaker is defined as a device designed to protect an electrical circuit from damage caused by overcurrent or short circuits by interrupting the flow of electricity.Short Circuit Breaking Current of Circuit BreakerThis is the maximum short circuit current which a circuit breaker (CB) can withstand before it, finally cleared by opening its contacts.When a short circuit flows through a circuit breaker, it causes thermal and mechanical stresses in the breaker’s c

What is High Voltage Testing?High Voltage Testing DefinitionHigh voltage testing involves procedures to ensure that electrical equipment can withstand various voltage stresses during its operational lifespan.Transformer Testing MethodsEssential to evaluate the integrity of electrical systems, including tests for dielectric strength, capacitance, and breakdown voltage.Test TypesThere are mainly four types of high voltage testing methods applied on high voltage equipment and these areSustained low

What is Circuit Breaker Maintenance?Circuit Breaker Maintenance DefinitionCircuit breaker maintenance involves switching off, isolating, and regularly checking and servicing the breaker to ensure reliable operation.Bulk Oil Circuit BreakerFor bulk oil circuit breaker, we should check contact burning. If burning is very light, remove the burn beads and polish the surface. If burning is quite heavy, replace the tips and arcing ring by new set. We should loose and tight the tips few times before fi

What is SF6 Gas?SF6 Gas DefinitionSF6 gas is defined as a compound of one sulfur atom and six fluorine atoms, known for its stability and use in electrical systems.Manufacturing ProcessSF6 gas is commercially manufactured by the reaction of fluorine (obtained by electrolysis) with sulfur.During process of producing of this gas, other byproducts like SF4, SF2, S2F2, S2F10 are also produced in small percentages. Not only these byproduct, impurities like air, moisture, and CO2 are also present in t

What is a Residual Current Circuit Breaker?RCCB DefinitionA Residual Current Circuit Breaker (RCCB) is defined as a safety device that detects and interrupts a circuit when there is a leakage current to the ground.Working PrincipleAn RCCB operates based on Kirchhoff’s current law, which states that the total current entering a node equals the total current leaving it. In a normal circuit, the currents in the live and neutral wires are balanced. If there is a fault, like damaged insulation or con

Medium Voltage Switchgear DefinitionMedium voltage switchgear ranges from 3 KV to 36 KV and is used to manage and protect electrical systems.Types of MV SwitchgearIncludes metal enclosed indoor and outdoor switchgear, and outdoor switchgear without metal enclosures.Short Circuit Current InterruptionThe main focus of circuit breaker design is to that all circuit breakers should be capable of interrupting short circuit current with a high degree of reliability and safety. The number of faulty trip

What is Electrical Switchgear Protection?Switchgear DefinitionA switchgear is defined as all the switching devices used in power system protection. It includes devices for control, metering, and regulating electrical power systems. When assembled logically, these devices form switchgear. In simpler terms, switchgear refers to systems that switch, control, and protect electrical power circuits and equipment.Switchgear and ProtectionWe all know about low voltage switches and re-wirable fuses at ho