We get this call a lot. Seriously, A LOT. Enough for us to want to take some time to address this so that you as a homeowner can feel a little better about what happens when a breaker trips.
Resetting a Tripped Breaker
Let’s start with resetting a circuit breaker. Don’t laugh. You would be surprised to know how many calls we get from people who have never reset a breaker before. Maybe they moved from a newer home to an older one and have never had an electrical problem before.
When a breaker trips, it will go into the neutral or “tripped” position. If you’re looking at your electrical panel you’ll see that the handle of the tripped breaker will be in the center while all of the other breakers will be fully in the ON position. Before you can reset that breaker you must push the handle all the way to the OFF position before it will re-engage to the ON position. You should feel it click off before you’re able to turn it back on. If it re-engages in the OFF position, but then immediately trips back to center DO NOT TOUCH IT. Call us immediately. That means you have a short which we will go over here in a minute. Forcing the circuit back on can do some major damage and we will have to diagnose and clear the short before we can flip that breaker back on.
Why Did It Trip?
Your circuit breaker has tripped due to one of two reasons. You either have an overcurrent condition or a short. With an overcurrent condition, there was more current on the circuit than the breaker is rated for and it tripped to safely protect any wiring and equipment associated with that circuit. With a short circuit, the breaker has tripped because the hot wire has come into contact with either a neutral (grounded conductor) or a ground (equipment grounding conductor). When you have a short circuit, it causes a sudden fault current to travel back to the panel, tripping the breaker. This is often slightly harder to diagnose as the source of the problem will take some good troubleshooting to pinpoint.
How Does a Breaker Actually Work?
Remember that the primary purpose of a circuit breaker is to prevent a fire. Every single wire in your home or business has very specific allowable ampacity. Any current flow over that amount will cause the wire to overheat and breakdown which is what causes electrical fires. The faster we can interrupt the current flow, the faster we can get that overcurrent condition safely off the wiring that comprises that circuit.
The inside of a circuit breaker has a bi-metallic strip that engages a spring loaded handle. When that strip has too much current flow on it, it will begin to shift, releasing the spring mechanism which sends the handle to the tripped position while opening the flow of electricity. When you reset the breaker, you are re-engaging the mechanism that closes the terminals inside the breaker allowing current to flow again. During a short circuit condition, the electromagnetic field created by the fault current is so strong that the breaker will trip within milliseconds. This is what electricians refer to as a “dead short” and often happens when the wiring or device that’s causing the fault has become so severely damaged that the breaker will not re-engage at all.
Overcurrent conditions are more common than short circuits. The most common tripped breaker calls are always related to space heaters. Even though you can buy an inexpensive space heater almost anywhere and plug it into any standard three prong outlet, most people doing realize that these devices can draw over 1500 watts which is a considerable amount of power especially on a residential lighting circuit. Space heater issues are also extremely common in commercial office spaces where certain areas don’t have direct control over their own heating system. If you find yourself constantly relying on a space heater we urge you to call us so that we can come up with a permanent solution to rectify the problem with hardwired electric heat or a designated circuit with a heavy gauge wire.
Another big one is hair dryers. Bathrooms are now required to have a designated 20 amp circuit so that a hair dryer can be used freely without affecting any other circuits but this was not always the case. In older homes the bathroom receptacle might be tied into a nearby 15 amp lighting circuit. Even a moderate setting on a hair dryer can draw over 12 amps, so if there is anything else being used on that circuit then you have an overcurrent condition tripping the breaker.
If you ever see any smoke, arcing, or blackening around an outlet or the prongs of an appliance cord, call a licensed electrician immediately. You may have more than an overcurrent condition on your hands.
We hope that a little background on circuit breakers helps you use better judgement when you have your next electrical issue. We urge you to err on the side of caution and call us if anything seems unsafe. We have seen dozens of electrical fires in both old and new homes. Most importantly, never work on your own electrical panel or manipulate a circuit breaker. That breaker has been intentionally sized based on circuit load demand to act as the last line of defense during an electrical fault. Be safe and protect your investment!