JD’s Blog | Do Your Lights Flicker or Flutter?
Have you ever been sitting in your living room reading the paper, and something flickered? You’d swear that your lights just dimmed or brightened, but you’re not really sure? You go back to reading the paper…. and it happens again. You look up, staring, waiting, nothing! You keep staring at the lights, seemingly forever, and….nothing! You start to question yourself. Did I imagine it? You go back to reading and then, it happens again! Only this time you actually saw it! You’re NOT crazy! You’re NOT imagining things! Thank God! It’s really is flickering, fluttering lights!!! Wait a minute….That’s not good! What could be causing this to happen? I can answer that for you.
As our illustrious government officials like to say, “I’m here to help you”. But I’m not from the government! I’m a master electrician and I’ve had extensive hands-on experience in the electrical industry for over 40 years. Yes, I’m old. Flickering lights can be a nuisance and complicated to fix even for professional electricians. They can also be the foreboding threat of an electrical fire. There are a number of possibilities why the lights are flickering, brightening, dimming, and driving you nuts! It’s all going to boil down to one or more forms of a bad or loose wiring connection, somewhere. But where? I usually have a pretty good idea where to start looking: It’s somewhere between the service entrance from the utility and the light fixtures that are flickering! I know, I’m a wise guy. That said, I do know what I’m talking about. Believe it or not, I usually find the problem in a wall socket outlet, not at a light switch or the panel. I say usually, because that’s not the only reason why this could be happening.
When I’m called out for flickering lights, I’m already in diagnostic mode as to the cause even before I arrive. The wires in the light switch box could be loose, or the switch could be going bad. The breaker could be bad. Maybe the wires in the panel are loose. Maybe there’s a loose neutral somewhere. Somewhere? Here’s what I know for sure: It’s most assuredly a loose connection, of that much I’m certain. But you might be surprised to learn where it most often is.
First, a quick lesson in basic residential wiring: What is a lighting circuit? A general lighting circuit consists of a current carrying cable supplying 120v to a number of outlets, in a number of rooms, consisting of two insulated conductors. It’s a two conductor cable commonly known as two wire cable. For a 15 amp lighting circuit, the cable, or wire if you will, is called 14/2 & it’s usually Romex cable. “Fourteen” refers to the size of the conductors and “two” refers to the number of conductors wrapped within the cable. The two conductors, or wires, are a black “hot” and a white “neutral”, plus a bare ground wire. “Outlets” refer to any wall socket, ceiling or wall light or switch outlet box. Switches aren’t counted because they don’t consume electricity. They only turn it on and off. For example, an average lighting circuit consists of maybe twelve wall sockets and three wall or ceiling lights, for a total of fifteen outlets, 15 being the average number of outlets on a lighting circuit for three rooms. It can always be less. The term “lighting circuit” refers to a circuit that combines lighting fixture outlets and wall socket outlets powered by a single circuit breaker. If the total wattage exceeds 1850 watts, the breaker should trip.
Getting back to flickering lights: To put this into perspective, think of an everyday common AA battery. It has two posts, positive & negative. A flashlight will flicker if either one of the post’s connections become loose, and it doesn’t matter which post. Same with your basic AC electricity. In residential wiring, instead of a flashlight, it’s a 120v light bulb, or anything else that can be plugged into a wall socket. They all require a positive and a negative wire. But with household electricity, we call what would be positive “the hot” wire and what would be the negative “the neutral”.
The hot wire is connected to a circuit breaker inside the panel. The neutral wire is connected to a grounding bus inside the panel. Every light fixture and every wall socket (called a receptacle) requires a positive and negative wire, or in our terms a hot and neutral, just like a flashlight. Except in a house, think of a bunch of flashlights all connected together by the positive and negative wires joined together, outlet to outlet. For wall sockets, think of a flashlight that plugs in. The hot and neutral are wrapped together in a plastic sheathing along with a bare ground wire.
Hence, a 14/2 Romex cable begins at the circuit panel, is then routed to the first outlet in the circuit, and from there it loops from outlet box to outlet box to the last outlet of the circuit. In order to carry the hot and neutral electricity to every outlet in the circuit, each hot and neutral wire must be connected together at each outlet box in order for the current to continue to the very last light or wall socket in that circuit. Still with me so far? And the fastest way to connect these wires together at each outlet is by means of “stab-lock” or “speed-wire”. All plug sockets, or receptacles as they’re known, have six small holes in the back, three on each side, one side hot (positive) the other side neutral (negative). So when a two conductor cable is terminated into the first outlet box and the next cable leaves that outlet box for the second outlet box in the room, those hot and neutral wires must be connected together. How do we do that? Most electricians simply stab the wires into the holes on the back of the plug, which literally stab-locks them together. It saves lots of time by not having to physically twist each wire together at every single outlet, requiring an added tail-off wire from the twist onto the devise. Hence the term “speed wire” devises. When you stab the wires into the back of the receptacle, the receptacle connects them together for you. It’s legal and it’s fast. By the way, quality grade receptacles also have 2 screws on either side for a better, tighter connection. But here’s the problem with stab-lock or speed wiring connections; After time, and once the wires have become hot, then cool, then hot, then cool, they have expanded and contracted from the wattage drawn from plugged-in appliances or lights. It has to get there by passing through each and every stab-lock connection between the draw of current and the circuit breaker! It’s literally an electrical tug of war! Eventually, one of those many, many stab-lock connections is going to wear out and ” break & make & brake” contact! It only takes that one first, single, loose stab-lock hole to begin wearing out. It doesn’t matter if it’s on the hot side or the neutral side; all the lights and receptacles beyond that single loose connection are going to start flickering or even shut off completely. Once it’s been fixed at that one isolated location, the tug of war shifts to the next loosest stab-lock connection in that circuit. It probably won’t happen right away, but it will happen again. And space heaters are notorious for causing the stab-lock connections to fail. Space heaters are the strongest of all the tug of war competitors. Hair dryers and curling irons are also culprits. Clothes irons, or any high wattage appliance will cause a loose stab-lock connection to fail eventually. But when the wires at each outlet are physically spliced together first before attaching them to the devise, nothing can cause that circuit to open again. If a space heater or a hair dryer are both running on the same circuit, at the same time, the breaker will trip.
By now your head is spinning and you’re asking “what do we do? How do we fix this “? And by the way, this is also one reason for intermittent power outages. After an outage, the wires will cool down and contract, and they can reconnect inside the stab-lock hole. Everything suddenly comes back on again all by itself. It’s also why at times, when lights & plugs are dead, the breaker is still in the on position. There is a loose connection at an outlet within that circuit and everything past that loosely connected outlet goes out. I then have to isolate which receptacle outlet has the loose connection. Will I replace the receptacle with a new one and use the same method of stab-lock speed wire holes again?? Of course not!!! My electricians are trained to physically splice all wires together ahead of the devise, then pig-tail a lead wire from each hot & neutral splice, onto each of the side screws on the devise. We absolutely do not EVER use the stab-lock connections! Our method ensures that the flow of electrical current is unbroken, for both hot and neutral wires, even when the devise is removed, because the devise is no longer being used to connect the wires together! Make sense? I recommend replacing all receptacles and switches by pig-tailing all wires at all devise connections. The power can never be lost, and the lights will never flicker for this reason ever again. Aside from the flickering lights, worn out receptacles slots when the cords have become loose, can cause fires. The cord end can also melt. If your devises are more than 20 years old, replace them and insist on the pig-tail method of installation. This will end most flickering light issues. But it’s not the only reason why lights flicker.
As I said earlier, a poor stab-lock connection is the most common reason for flickering lights. But there are also other reasons that could cause your lights to drive you nuts. A light switch could be going bad. It happens. Nothing lasts forever. The “home run” (first wire exiting the panel feeding the circuit) might have a loose neutral connection in the panel, or the breaker could be arcing at its connection point in the panel. The panel itself could be on its last legs depending on its age. Whether or not you have an underground supplied electrical service or an overhead supplied service from a utility pole, they too can cause problems. I’ve found loose connections at the weather head above the electrical meter box. I’ve found loose connections in the hand-hole out at the street for underground services. But, if it’s something that’s ahead of the electrical meter, then usually the entire building is experiencing electrical issues. This type of loose connection ahead of the electric meter effects the entire panel, which effects every circuit in the house, or at least half of them. Your panel is powered by two hot wires and one neutral wire from the utility company. Each hot wire is 120v to neutral or to ground. The voltage between both hot wires is 240v. Your home’s 120v circuits are evenly divided between the two hot wires in the electrical panel, called “phases”. Half of your home’s circuits are on A phase and the other half on B phase. A&B share a single common neutral, called a three wire system. If you have an electric range, electric dryer, spa, central air, electric cook top, electric water heater, those appliances use both A phase and B phase because they operate on 240v. If there’s a problem with either A or B phase ahead of the electric meter, then you’re going to have half your lights & outlets out, flickering lights, & none of your 240v appliances will operate. They need both phases to operate.