Understanding the electrical system in your home can be difficult, especially if you see something that isn’t what you expected. If you find a circuit breaker with two conductors in your electrical panel or suspect that two circuits in your home might be connected to the same circuit breaker, you may wonder if the design is intentional or safe.
What is a double tapped breaker? A double-tapped circuit breaker is where two conductors share the same circuit breaker. A circuit breaker designed to accept two conductors will be labeled accordingly, but if the breaker is not labeled to be double-tapped, the situation might be dangerous.
We’ll explain more about what a double tapped circuit breaker is, what makes it unsafe, and how you can fix dangerous conditions.
Do You Have a Double Tapped Breaker?
A double-tapped circuit breaker can be a dangerous installation in your home’s electrical panel if done incorrectly, but fortunately correcting a double tapped circuit breaker can be fairly straightforward.
When two conductors connect to the same lug on a circuit breaker or the same neutral bar, the circuit breaker is said to be double-tapped. Typically, a standard circuit breaker in a residential home is rated for about 20 A (amps) of power with a corresponding 20 A circuit breaker. If the circuit draws more than 20 amps of power, the circuit breaker will break the circuit to prevent fires, property damage, or electrical shock.
Normal circuit breakers are not designed to hold two wires, and even though the wires may look to be securely fastened and secure, the wires are most often not properly tightened. Improperly fastened wires can overheat, arc, spark, therefore causing fires, arc flashes, or electric shock.
Even if the wires happened to be secure enough, at least for a time, with two conductors connected to the same circuit breaker the circuit breaker may not work as intended. If both wires are in use at the same time, the circuit breaker may detect it’s maximum 20 A draw early and trip frequently.
Other times, it may not detect a dangerous draw of current and not trip at all. Even if the wires or breakers don’t cause a fire at the panel, the fault in the system, like a faulty appliance, could become live with electricity. If someone touched the live piece of metal, they could be dangerously hurt.
How to Identify a Double Tapped Breaker
While most circuit breakers are not designed to accept two conductors, there are some circuit breakers that are listed to be double-tapped. Labeled circuit breakers should have clear notes on their face that when you open your panelboard you can see the label for the double tapped breaker. These breakers will clearly have two points of connection on the lug and the wires will not have to touch to connect to the circuit breaker.
How can you tell if your double tapped breaker is not designed correctly? In most cases, two wires will enter the circuit breaker at the same location, possibly touching. In some instances, the bare metal conductors will even be touching, which is very dangerous. Do NOT touch any bare wires in your panel.
When you open the door on your panelboard, you will typically see the black circuit breakers in the middle, with a metal cover plate around them. The cover plate usually prevents you from seeing or touching the wires that enter each circuit breaker. Homeowners without experience working on electrical equipment should not remove this cover. Removing the cover incorrectly can result in electrical shock and even death.
To inspect the panelboard, an electrician or inspector may open the panelboard. They will make sure the installation does not have any visible safety issues, such as the presence of water, rust, loose wires, or bare conductors anywhere in the vicinity. If the installation is clean in safe, they may open the front door and flip the main breaker into the off position.
Even with the main breaker off, the power upstream of the panel is still live so care must be taken not to touch anything upstream of the panel. Other components may also still be live. The inspector or electrician may test to make sure that there are no live components using a voltage detector.
After ensuring the power to the panel is off, they can use a drill to remove the front cover from the panelboard. Behind the panel, the wires and conductors entering each circuit breaker should be easy to see.
If you find that you have a double tapped breaker in your electrical panel, call an experienced electrician to correct the installation.
How to Correct a Double Tapped Breaker
You may not have noticed if you had a double tapped breaker unless you had a home inspection where the inspector made a note to recommend repairs. How do you correct a double tapped breaker? Thankfully, fixing a poorly installed double tapped breaker can be easily done by an experienced electrician.
The easiest option to fix an unlabeled double tapped breaker is to install a labeled double tapped breaker. With the power to the panel turned off, the existing circuit breaker can be disconnected from the wires and each wire landed on their own connections to a labeled circuit breaker. However, some panels may not be able to accept a new breaker.
New or refurbished circuit breakers may not be produced for older panels that are no longer supported by the manufacturer. Some panels may not be able to accept a properly labeled double tapped circuit breaker.
If your panel cannot accept a double tapped circuit breaker, the double-tapped conductors could be split between two different circuit breakers. Your electrical panel will need to have at least one spare space for a new circuit breaker. Splitting the two conductors between two circuit breakers will provide you with two separate circuits, allowing each circuit breaker to operate as designed.
If your panel has a list of the use of each circuit breaker, called a schedule, unused breakers may be noted as “spares.” It’s not uncommon to find that the panelboard schedule is missing or has not been updated since the panelboard was installed. To verify if any of the breakers are not used, the panelboard cover would need to be removed to find circuit breakers without conductors connected to them.
Finally, another option to correct a double tapped breaker includes installing a tandem breaker. A tandem breaker is a breaker that is designed as two circuit breakers that only take up the space of one breaker. They are sometimes called duplexes, split, twin, or double breakers. The panel must be designed to accept tandem breakers. The manufacturer should list what types of tandem breakers are allowed, how many can be used, and where in the panel they should be installed.
Carefully read any notes or descriptions on your panelboard to see if the information was provided, if not, you may need to check the manufacturer’s website, call the manufacturer, or ask a qualified electrician.
Altering Your Double Tapped Breaker
Be careful not to trade one dangerous condition for another. Fixing a double tapped breaker should be done by a licensed electrical contractor. Swapping a double tapped breaker for another incorrectly installed or designed breaker can be just as dangerous. Playing around with electricity in your home can risk your own personal safety or your property’s! However, fixing a double tapped breaker can be an easy fix to put your mind at ease.