Why Do My Lights Flicker? Electrical Contractor Explains!
Why Do My Lights Flicker?
Sometimes there can be nothing more annoying than having your lights flicker or dim throughout the day or night. What’s causing them to flicker and or dim may not be such an easy answer. However, Here are a couple of questions you want to ask or observe first to get to a possible resolution.
Questions to Answer
1.) When do my lights flicker? Only when a large appliance kicks on such as a heat pump or A/C unit or do they flicker any time of day or night without anything kicking on and or running. Try as best you can to observe what you have on and if it’s related to you’re A/C or Heat Pump kicking on.
2.) Is it all the lights that are currently on in the house that seems to flicker or the same light or sets of lights that always flicker? Again, try to notice and make note of which lights, or is it all lights that are on when the flicker occurs.
3.) How often does the flicker occur? Again, try to make note of the same things as above.
Let’s take a look at each situation one by one and why this may be occurring.
Same Light or Lights Flicker in the same general area and NOT throughout the entire home:
This problem can occur from simply having bad light bulbs to a bad connection between the light bulb and the light fixture socket to more complex troubleshooting issues like a loose wire in that particular circuit. A complete circuit diagnosis should be performed in this case to find the loose hot or neutral conductor causing the issue. These can be complex troubleshooting issues for the average homeowner as a single circuit in your home may have 30-50 connections to inspect and evaluate. The loose connection could be in a receptacle, a switch, a light, a j-box, or at the main electrical panel. Loose connections are a serious issue and should be addressed as soon as possible.
Lights throughout the house and or nearly half of the Lights in the house Flicker:
If you are noticing random lights flickering and or sometimes nearly dimming and it’s throughout the house or a large part of the house and you are sure it’s not a large appliance kicking on causing the problem then make sure you have an electrician look at your main electrical service. If it’s not the same circuit always flickering it’s a sign that you could have loose service conductors in your main electrical panel or in your meter base. Again, this could be a very serious issue so contact your local electrician asap to address this issue for you. Your service conductors heat up and cool down with use all day every day 24 hrs a day 7 days a week. Over time this can cause the service conductors to loosen up and as they loosen up they create even more heat. Eventually this can cause the service conductors to burn up lugs on your main breaker, or the service conductors themselves to burn up, to even more serious issues. The key is to put an electrician’s eye on this for you and in the future make sure you have an electrical maintenance plan in place to help prevent this issue from ever occurring.
Lights Flicker When a Large Appliance (Outdoor A/C or Heat Pump) kick on:
If your lights flicker every time for that split second when your outdoor A/C unit or Heat Pump kicks on and you’re fairly certain you have the flicker tied to that then here is what we have found. First off, it’s a common problem with large outdoor units to cause this. Why? They can draw up to 100+ Amps for that millisecond that they start up (otherwise known as locked rotor amps) most homes only have a 200Amp main electrical service so imagine needing half of your homes electrical power just to start that outdoor unit. Locked Rotor Amps by definition is the amount of electrical energy required to start the motor. This required energy is much greater than the Full Load Amps or Running Amps because of the required energy needed to not only start the motor but provide this transferred power to the outdoor unit’s motor to operate the designed work function. Once it’s up and running the require energy or amp draw goes way down. Again, all this occurs in milliseconds upon starting. Ok, let’s get past the technical stuff….. what can you do about it? Here is the order in which I would go about resolving this problem.
a.) Contact your local electrician and or (the person who wired your outdoor unit if known) and just make sure they have the outdoor unit wired to the max ampacity and that the wire size and fusing is correct and all connections are tight. Have them look in the main electrical panel and if necessary the meter base to make sure all electrical connections are tight and that we don’t have loose service conductors. It’s always good to just make sure the basics are right to begin with. If all that is good then my next step is…..
b.) Contact your local HVAC contractor or again (the person who installed it, if known) and see if they have a soft start kit that they can install on the outdoor unit. This doesn’t always work but it can definitely help as it will try and lessen the large amount of current required all at once to start that motor. You may already have one on the outdoor unit as a lot of the newer models these days have them however it’s worth the call to at least ask regarding your particular unit. If you have a soft start kit and you electrical checks out ok then here is the likely culprit.
c.) If all the above is good and you are still experiencing light flicker throughout the home when the outdoor unit kicks on then the problem probably lies between your meter base and the transformer that feeds your home power. The wire size feeding your home may be too small for your homes load and or more likely the transformer feeding your home may be too small. Contact your local utility company to look into this for you. Most will look into this at no charge to make sure you are getting quality power to your home.
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