Unsa ang Reaksyon sa Standard Breaker sa Electrical Fault?

Operasyon sa Circuit Breaker Alang sa Proteksyon sa Fault

Ang standard nga circuit breaker usa ka kritikal nga pananglitan sa seguridad nga gihimo aron mobati sa elektrisidad sa panahon sa mga fault sama sa overloads o short circuits, pinaagi niining pagbatas sa pinsala sa sistema sa elektrisidad, sobrang init sa mga wire, ug mga panganib sa sunog. Ang iyang aksyon sa proteksyon naghatag og seguridad ug kabalakaan sa circuit.

Proteksyon sa Short Circuit

• Unsa ang Mabati: Ang short circuit mao ang nangyari kung adunay low-resistance path (e.g., direct contact sa live ug neutral wires) nga nahimo og abrupt nga surge sa current nga dako pa sa rating sa circuit.

• Tubag sa Breaker: Ang breaker nadetect ang instantaneous spike sa current ug trip almost immediately (within milliseconds), cutting off the flow to:

• Prevent excessive heat buildup from damaging components.

• Mitigate the risk of fire or electrical arcs.

Overload Protection

• Unsa ang Mabati: Ang overload mao ang nangyari kung ang total nga current nga gi-draw sa mga connected devices (e.g., multiple appliances o high-power equipment) dako pa sa safe capacity sa circuit sa panahon.

• Tubag sa Breaker:

• Prevent wiring from overheating and deteriorating insulation.

• Avoid potential fire risks from prolonged overcurrent.

• The breaker’s internal thermal mechanism senses the sustained excess current.

• As the current persists, the breaker’s heating element warms up, causing a bi-metallic strip to bend gradually.

• Once the strip bends sufficiently, the breaker trips, disconnecting the circuit to:

Paugnay sa Standard nga Circuit Breaker Sa Panahon sa Electric Faults?

Ang typical nga standard circuit breaker wala makadetect sa ground faults o ang absence sa neutral wire. Nga maghatag lamang sa proteksyon kontra sa short circuits ug overloads. Kini ang rason nganong ang National Electrical Code (NEC) nag require sa paggamit sa Ground Fault Circuit Interrupter (GFCI) breakers aron masiguro ang maayo nga proteksyon para sa mga devices ug personnel.

Sumala sa ubos ang mga circuit examples nga nagpakita kung unsa ang standard breaker behabe sa normal ug fault conditions:

Normal Condition

Sa diagram sa ubos, ang lighting circuit gi-control ug gi-protect sa 15-amp breaker, supplied with 120V from a 120V/240V main panel.

Tungod kay walay fault sa circuit, tanang components operate normal, ug ang light illuminates as intended.

Short Circuit / Overload Condition

Karon, consider a scenario where a short circuit or overload occurs—e.g., if the hot wire comes into contact with the metallic housing of a device (such as a bulb holder). In this case, a fault current is created, traveling back to the power source through the ground wire. The ground wire is connected to the neutral wire at the main panel, forming a low-resistance path that completes the circuit.

Due to the ground wire’s extremely low resistance, a substantial current (up to 600 amps) surges through the circuit during a fault, creating a severe overload. The breaker’s internal mechanism instantly detects this excessive current and triggers a trip action. The 15-amp breaker then rapidly disconnects the circuit from the main power supply, safeguarding both the electrical device and personnel from potential hazards like overheating, arcing, or electric shock.

Fault Detection and Tripping

As illustrated in the diagram below, the 15-amp breaker trips immediately upon detecting a fault current that surpasses its rated capacity. This action disconnects the circuit from the main power supply, providing robust protection against both overloads and short circuits.

Standard Breakers and Ground Faults

As previously discussed, standard circuit breakers do not protect against ground faults—situations where electricity flows unintentionally to the ground—or broken neutral conditions, both of which pose significant safety hazards. In such scenarios:

• Ground Fault: Current deviates from the intended circuit path and flows to the ground (e.g., through a person or faulty appliance), creating a dangerous shock risk.

• Broken Neutral: A disconnected neutral wire can cause voltage imbalances, forcing current to seek alternative paths (e.g., through equipment casings or ground wires), which may lead to overheating or electrical shock.

In both cases, the fault current may complete the circuit through unintended routes, bypassing the standard breaker’s overload/short circuit protection mechanism. This is why specialized devices like Ground Fault Circuit Interrupters (GFCIs) or Arc Fault Circuit Interrupters (AFCIs) are required for these specific hazards.

This can lead to current flowing through unintended pathways, including neutral and ground conductors. Moreover, any exposed metal components in the circuit may become energized, potentially carrying dangerous voltages of 72V or 120V—creating a severe risk of electric shock or fire.

To address this issue, a GFCI breaker should be used instead of a standard breaker to ensure safety in the event of ground faults.