How to Troubleshoot a Tripped Breaker

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How to determine and correct problems which cause breakers to trip.

Most of the time a, circuit breaker trips people simple go to their electrical panel find the offending breaker and reset it. But what happens when the breaker does not reset, or trips often, you can troubleshoot the problem yourself and depending on the problem, repair it or hire an electrician to do the repair for you. Circuit breakers are designed to trip, unlike older fuses in a fuse box that are designed to melt a thin metal strip, and turn off power whenever the following potentially dangerous situations occur:

• Overloaded Circuit

• Short Circuit

• Ground Fault

Types of Breakers

There are three types of residential circuit breakers; magnetic circuit breaker, thermal circuit breaker, and thermal magnetic circuit breaker.

Magnetic circuit breakers are equipped with an electromagnet that gets increasingly strong as the flow of electricity increases. The magnet activates a cutoff switch when too much power enters the circuit. Thermal circuit breakers employ metallic strips that bend and activate a cutoff switch when temperatures get too high. Thermal magnetic circuit breaker employs both methods and protects against electrical current surges with a thermal breaker, and against a complete short-circuit, by a magnetic trip feature.

 

Internal components of a circuit breaker

(Source: www.IAEI.org)

Circuit Overload

The most common cause for a breaker trip is when a circuit has more connected electrical load than it is supposed to have. When more current runs through the circuit than the circuit was intended to take, the circuit breaker is designed to trip to break the electrical connection.

Circuit breakers come in different amperage ratings that determine how much current that can safely flow through the circuit. If a typical 15 Amp circuit breaker is protecting a series of receptacles and you have a hair dryer, a computer, television, and fan plugged into various receptacles on the circuit, the circuit breaker trips to prevent overheating which can cause a fire. The size of the wire also relates to the amperage of the circuit breaker, but we will go over that in a little while.

It is also important to understand that the size of the breaker, whether it’s 15 or 20 amps, is a nominal size. Breakers are designed to trip above 80 percent of the rated load; this is why vacuum cleaners or circular saws state that they are 12 amps. Most residential circuits are 15 amps, and 80% of 15 is 12. Now you know.

Correcting an Overloaded Circuit

Too many devices plugged into one outlet or multiple outlets connected in a circuit.

• Relocate lamps, heaters, irons, hair dryers and other high load devices to a different circuit with less load.

• Turn off some of the devices on the circuit to reduce the load.

• Inspect the plugs and cords of the electrical devices connected to the circuit. Damaged plugs and twisted or pinched cords can develop a short after they have been in use for a while and trip the breaker.

Tip: Another way to tell if a circuit is nearly overloaded is to touch the knuckle of your index finger to the surface of the circuit breaker to see how warm it is. All electrical wires heat up when current passes through them, so they can be slightly warm, but if you have a breaker that is hot or substantially warmer than the rest, you may have to have a electrician increase the gauge of wire to the circuit or increase the breaker size.

Short Circuit

A Short Circuit is a very serious problem which can cause breaker tripping. A short circuit happens when the hot wire (black) touches another hot wire or touches a neutral wire (white). A break in the circuit wiring can also cause a short. These can be difficult to troubleshoot since the cause can be the wiring in your home or in something you have plugged into an outlet.

Short Circuit Inspection

• Confirm that power is off to the outlets.

• Inspect your power cords for damage or a melted appearance. Space heaters which are on for long periods of time can cause the neutral side (the longer of the two slots) of the outlet to overheat and begin to discolor or even melt.

• Check your outlets and plugs for the smell of burning or brown or black discoloration.

• Remove the receptacle cover and check the insulation on the wires. Make sure it is not brittle and cracked and touching another wire, the ground wire, or the box if it is metal.

• Inspect all the outlets and switches in the circuit.

• If ceiling light fixtures are connected to the same circuit, remove the fixture and inspect the wiring inside.

• If you can’t find a problem, contact an electrician as soon as possible.

You can also purchase a receptacle tester to check if receptacles are wired properly.

Receptacle Tester

To narrow down if the short circuit is a device or the house wiring, follow this procedure:

• Unplug all devices connected to the circuit.

• Turn off all light fixtures on the circuit.

• Go to the electrical panel and reset the breaker.

• If it trips immediately, the short is in the wiring of the circuit.

• If the breaker does not trip, turn on any light fixtures connected to the circuit.

• If the breaker holds, the short circuit is being caused by something plugged into the outlet.

• It is better to purchase a continuity tester for a few dollars and follow the instructions for testing the appliances or devices. Otherwise, plug each item into an outlet and turn it on to find the faulty appliance or lamp and then have it repaired.

Note: Each time a breaker trips you can damage it and it may have to be replaced.

Continuity Tester

Other causes for repeated breaker trips can be due to loose load terminal connections on the breaker. If you can’t find the cause for circuit breaker tripping, hire an electrician an have him check the electrical service panel and all the connections inside the panelboard.

4 comments

Dom Squeglia
10
Posted on Aug 19, 2018
Dom Squeglia
10
Posted on Aug 19, 2018
Daniel Snyder
0
Posted on Jun 17, 2010
Jerry Walch
0
Posted on Jun 17, 2010