A circuit breaker is an automatic switch that cuts off electrical current if certain conditions are reached. They are used to protect people and electrical devices from fire and injury. Unlike fuses, which are single-use, circuit breakers can be reset.

A circuit breaker uses mechanically stored energy to open contacts and interrupt current. This is done using either a bimetallic strip or an electromagnet design.



Short Circuit

Electrical short circuits occur when a hot wire comes in contact with a neutral or ground. This allows electricity to take the shortest route instead of the circuit it’s supposed to follow, which can cause fires or shocks. This is another situation that should be left to the professionals, but if you flip your breaker back on and it trips again right away, you probably have a short somewhere in the wiring or an appliance connected to that vacuum circuit breakers.

Unplug all the devices in that circuit and check for any scorch marks or signs of melting elements. If you do find a problem, call a licensed electrician to locate the source of the short and fix it. This may involve splicing wires or adding additional outlets and light switches to the circuit. Loose or corroded connections can also trigger the breaker to trip by creating heat that’s too high for the breaker’s temperature rating. This is known as arc fault and requires a special type of circuit breaker called an arc-fault circuit interrupter.



Ground Fault

Unlike short circuits, which can cause a sudden current surge that can burn up wiring and create a fire hazard, ground faults occur when an unintentional pathway of straying electricity forms between the equipment grounding conductor and the ground. This results in current flowing through the earth with almost no resistance, which increases the amperage to dangerously high levels that could cause a fire or electrocution.

The trip mechanism in a circuit breaker is designed to sense these conditions and open the contacts, interrupting the flow of electricity. The ground fault detection, which can either be built into the breaker or external to it (GF detector installed in a j-box), compares the outgoing and returning currents. If they aren’t equal, the breaker will trip. This protects workers from potential injuries and property damage that can be caused by a fire or electrocution. A common cause of this is water leaking in electrical boxes or wires getting pinched behind devices or inside a backbox.



Loose Connections

Loose connections within the breaker panel can lead to a faulty breaker. If you are seeing scorch marks or a burnt smell it may be time to call an electrician for a breaker panel repair.

When wires are tight to the terminal they make a good electrical connection that allows electricity to flow through with minimal resistance. When the connection is loose, however, more resistance forms which causes heat and can elevate current to dangerous levels. When the breaker panel detects this it trips to protect you from fire.The contacts on a circuit breaker are made from coated metal and are highly resistant to corrosion and rust. If your breaker panel is showing signs of corrosion or rust it’s time to call an electrician to have the main bus bar replaced and the connections checked.