A double-tapped breaker occurs when someone attaches more than one wire (conductor) to a breaker. It is generally not allowed and can be a fire hazard under certain conditions.
If you have had a home inspection in the past, say, 300 years, there is a good chance your home inspector wrote something in the electrical section of your report along these lines:
A comment in your home inspection report like this one is horrible.
Besides being one of the worst written explanations of a problem I have ever forced my fingers to type, it leaves you, the buyer/homeowner, with little to no information about what the heck is going on here.
Unfortunately, most home inspectors do not take the time to write proper explanations about the problems they discover during an inspection and poorly written comments like the one above will leave the Realtor and buyer scratching their heads about what needs to happen (see example below).
There is also a slew of new, undereducated home inspectors who simply do not know the rules for double-tapped breakers. Below is an image from a home inspector’s report stating the double tapped breakers in this panel need to be corrected for fire safety.
They are half right in that double tapping a breaker can lead to a fire under the right conditions. However, the breakers in the image are Square D, and they are designed to accept two wires. Double tapping a Square D breaker is fine, as long as a few rules are followed. We will cover that later.
This article aims to explain what a double-tap is and how it can be easily corrected. I hope a few new home inspectors take the time to read through this so mistakes like the one below can be avoided.
WHAT IS A DOUBLE TAPPED BREAKER?
A double-tapped breaker, more commonly known as a double-tap, is when more than one wire is connected to a breaker (or to a busbar-but we will only talk about breakers for this post) an electric panel. The curveball here is that some breakers are designed to accept multiple wires, and it is not a problem with those types.
Circuit breakers are designed to protect the circuit, not what is connected to them.
In other words, we want to make sure the wires stay in good working order and don’t meltdown and start a fire.
Let’s first look at how to determine how many wires a breaker will accept, and then we will look into how to fix the problem if you have too many connections on a breaker. This, of course, is known as a double tap or even a triple tap if you have an extra stupid person working inside your electric panel.
WHY ARE DOUBLE TAPPED BREAKERS A PROBLEM?
It’s all about the connection between the wire and the breaker. If more than one wire is connected to the breaker, and that breaker is not designed for two wires, the chances of those connections being too loose is much greater than those with just one wire connected.
If the connection between a breaker and a wire becomes loose, it could cause overheating or, worse, start to arc between the gaps. Arcing is what starts a fire in an electrical panel. Making sure your breakers’ connections are tight and properly executed is very important to fire safety.
The issue with double-tapping a breaker has nothing to do with the load (demand) on the circuit. I see a lot of bad info floating around saying that more than one connection on the breakers can cause an overload on that breaker. That is 100% false.
SOME DOUBLE TAPPED BREAKERS ARE NOT A PROBLEM
As if the rules aren’t confusing enough, sometimes you can double tap breakers and it’s not a problem. There are a couple of manufacturers that rate and allow certain breakers to have these types of connections made to them.
So how do you know which is which? It’s printed on the breaker.
As far as I know, some Square D’s and some Cutler Hammer breakers are OK to double tap, but everything else is a no-no. If you know of another brand where this practice is acceptable, please let me know and I’ll add it to the list.
Note: Notice that both of these breakers state that you should not double tap the connections if an aluminum wire is involved. When aluminum (AL) wire is present, it is stated that you are only allowed a single connection. Homes with aluminum wire have a whole different set of rules that you can learn more about here- Aluminum wiring in homes.
HOW TO REPAIR A DOUBLE TAPPED BREAKER
Now that you know how to determine what a double tapped breaker is, let’s explore the options on how to correct them. These are all fairly simple, but if you don’t have past experience or knowledge with working inside an electric panel, it would be best to call in a pro. There are points inside these panels that can kill you in the blink of an eye, even if you turn off the main breaker.
PIG TAIL THE WIRES
This is by far the simplest solution, and to be honest, I don’t know why you would ever bother with any other repair when dealing with a double-tapped breaker. All you need is a small section of wire and a wire nut. Simply twist all 3 wires together and only connect the single wire back to the breaker. All done. Everything connected to this breaker is still limited to the breaker size itself in terms of amperage protection, and if you pre-twist the wires together before you cap them off with a wire nut, you’ll be good to go.
INSTALL A TANDEM BREAKER
If you need control over whatever each wire is connected to via a breaker handle, you can get tandem breakers for most modern electric panels.
These breakers allow for two single pole arms to be installed in a single-width slot in the electric panel. You just need to make sure you are installing them in a spot they are allowed. All panels should have a diagram on the door that tells you which breaker is allowed in what spot. Some allow tandems all over; some older panels don’t allow them at all. Every brand is different so you’ll need to check yours to know for sure.
ADD A BREAKER
If you have the room in your panel, you could always go the traditional route and install a new single pole breaker in an open slot. Single breakers are cheap (under $5), and this is the simplest repair in terms of technical skill. If you can turn a screwdriver, you can install a breaker.
INSTALL A NEW ELECTRIC PANEL
The vast majority of the time, one of the options above will take care of your double-tapped breaker woes. If you find yourself in a situation where it won’t, sometimes a larger panelboard may need- but those times are few and far between. Only your electrician can tell you for sure when it comes to needing a replacement panel.
For all the young and budding home inspectors out there who happen to read this, please feel free to steal my wording that I use for my home inspection reports about double tapped breakers. Don’t be that guy who writes crap like I have at the top of this post and call it an “explanation.” Be detailed. Be descriptive.