Hot answers tagged

52

Some light switches run a small amount of current through the bulbs even when off, usually to power small devices at the switch like a timer, motion sensor, or night light. Do your switches have either of those features, or something else like that? The way those devices work is instead of having a hot/neutral pair powering the switch, they just sit inline ...


39

Yes. The fixture is concerned with heat. Your LED light bulb makes about 9 watts of heat. Your fixture is rated for a bulb that makes 40 watts of heat. With an incandescent bulb, 98-99% of its wattage turns directly into heat. Even LEDs, 90% of their wattage turns into heat. For thermal planning, it's not worth pulling out the calculator. You're "close ...


33

Yes, it is because of the heat buildup in enclosed fixtures, and no you should not use the bulb in that ceiling fixture you listed unless you are willing to accept shortened bulb life. Your options are: Use the bulb in that fixture anyway and accept that they may burn out or dim prematurely Get LED bulbs that are approved for enclosed fixtures, e.g. many ...


29

Yes, that is fine "like" /"equivalent", etc. are based on light output. Limitations on fixtures is based on heat output. Some power (Watts) becomes light, the rest becomes heat. LEDs are more efficient and produce more light, and therfore less heat, than incandescent bulbs. Fixtures are rated on worst case scenarios. But a 15 W LED bulb ...


29

There are two completely different thermal objectives First, don't set other stuff on fire. That's decided by the thermal insulation of the fixture (think: thick insulation in down lights) and limits the size (in actual wattage) of any bulb, but it's mainly aimed at incandescents. Incandescent bulbs love hot places and work better there. A fixture succeeds ...


26

You've probably connected one of the 2 power wires to the incorrect traveler terminal on the switch. This switch can be used as both a standard two-way switch as well as a three-way switch. (A three-way switch is used when there are 2 switches controlling the same device.) In standard two-way arrangement, one of the power wires should be attached to the ...


23

I found the answer! @diceless set me on the right track in looking at where the foot of the bulb is connecting to the fixture. Since it was an older fixture (installed in the 80's, I think), the hot contact (Number 1 in this diagram ) was bent down, and it was connecting with the smaller bulb but not the bigger LED bulb. With the circuit turned off at the ...


21

SHORT ANSWER: NO PROBLEM LONG ANSWER: The maximum wattage limits are largely a function of heat. For incandescent lights, more wattage means more heat. And too much of a heat buildup could result in shorter bulb life and even risk of fire, especially in a fixture in which the bulbs are fully enclosed. While lighting has traditionally been sold by wattage, ...


20

Even if LED or even CFL bulbs create far less waste heat than a conventional lightbulb, they react far more adversely to the heating resulting from ANY waste heat. A lightbulb won't care if it is in an ambient temperature of 500°F, actually it will run more efficiently - anything with electronics in it is hard to make in a way that it will survive long in ...


19

The specs are out there, just not always so easy to find. For example, one Philips Hue is rated at 9.5W with max. standby of 0.2W. (Click "The bulb" on the right side under Technical Specifications). Using this bulb as an example, if it actually uses the full 0.2W all the time, 18H x 365D x 0.2W = 1,314 Wh per year. If your electricity costs 0.10/kWh, that'...


19

It sounds like you have light bulbs or fixtures directly controlled by Alexa/Google Home. A better solution, though sometimes a bit more work to install, is a smart switch. With a smart switch, the actual switch is replaced with a device that functions as both a physical switch and as a WiFi/remote/voice-activated/etc. device. There is actually a bigger ...


17

LEDs on AC Power Don't Like to be Dimmed. Period. (LEDs on DC can actually be dimmed quite easily - just look at an older battery powered LED device (like handheld computer games from the 1980s) and you can see the LEDs dim when the battery is low.) But most AC powered LED lights - whether complete fixtures or Edison bulb incandescent replacements - have a ...


17

I think you misunderstood the instruction manual. Where it reads "LED bulbs (9-Watt, Maximum)" is in the parts list. This is not giving the fixture rating. It is saying that the included lamps will use a maximum of 9W. As the manufacturer may source the lamps from multiple vendors, this makes sense. You will need to look at the fixture to determine ...


14

I called Philips about this issue. They said that it indicates that the bulb is broken and needs to be replaced. Some LED bulbs have enough electronics in them that they are able to have diagnostic circuits and to report errors in this manner.


14

However, if I only turn off the lights breaker, and go into the switch panel with my voltmeter, I am still detecting 100V AC across the switch (with it off), even though the lights stay off when I turn the switch on. … Can anyone tell me what might be going on? Coupling between wires (inductance and capacitance in parallel wires). You say you have strange ...


14

The specifications of the LED lights you have say they will dim down to 10% without any flicker or buzzing. Some lights don't go down that far, and some will go even further. Based on the manual for your dimmer switch, there is an adjustment to change the low end of the dimming range: I would assume the switch would be factory set to work with most lights,...


11

Are these the the type of motion sensors which use the neutral wire? A motion sensor needs power to work. Ideally it gets always-hot, and neutral, and then provides a switched-hot to the target bulb. Such a unit should work fine, I use them widely. However some motion sensors are designed like old school dimmers - they are designed to work in old-style "...


10

The manual is vague, but I think the trick here is what I like to call "old wattage". Back in the not-so-dark dark ages of light bulbs, everything was incandescent. Incandescent wattage was important because a light bulb with a 100 watt fillament puts out a LOT more heat than a 60 watt bulb. So if you put a higher watt bulb into many fixtures, it ...


9

It's not the wiring. It's the LEDs themselves. LEDs have a characteristic delay when turning them on which may be more than you're used to from a lifetime of incandescent bulbs. Swap the LEDs from one position to another, and the problem should move with the bulb. Replace the LED with the equivalent incandescent (temporarily) and it should go away ...


9

The first problem here is the "100W" claim, which you here treat as the reference standard from which to compare. Actually, it's the most dubious claim of the bunch, and has never been reliable. I suspect it's a common mistake for people to fixate on the "100W" number since it's a unit they're familiar with, and that's why manufacturers toss it on the box. ...


9

The maximum power ratings are set by the design of the fixture. If it says 9W max. then you run a risk or damage or fire by exceeding that. Going from 9 to 10 W is a GREATER than 10% increase.


8

Say your electrical bill is $100 a month. Now say you have a refrigerator, a computer, a window fan and your light bulbs in your house as your only electrical devices. Everything but your light bulbs are on 24/7. Fridge: 725W **NOTE MOST FRIDGES DON'T ACTUALLY RUN 24/7 THIS IS JUST FOR EXAMPLE PURPOSES* Computer : 125W Fan: 150W Lights (on 8 hours a day,...


8

For a multi-bulb fixture the LED units do not want to be in the area where high heat is generated as would be the case with incandescent or especially with halogen bulbs. CFLs have their own special considerations if they are used in situations with special types of lamp dimmers. Such special dimmers may not be compatible with LED lighting modules. ...


8

Most 3-way lighted switches work by adding a light between their line and load terminals: This actually causes a small current to flow through the load (light) -- with incandescent or fluorescent bulbs, it's not enough to actually cause the light to go on. But with your LED blub, it's enough to at least start the bulb. Your potential solutions: Replace ...


8

This is splitting hairs... The concept of "grey energy" for powering of parasitic devices is severely overblown. You cannot just shut down a power generation plant, the plant ITSELF is a "parasitic load" on the grid if nobody is using that energy. So worrying about fractions of a watt, even spread across the entire planet, is an exercise in futility compared ...


8

You don't use a grommet in this application but rather an appropriate clamp. The correct type depends on what you are connecting here but the usual thing for non-metallic cable is something like this: https://images.homedepot-static.com/productImages/7b668807-9db0-42c3-86b1-e9ec7481045c/svn/halex-conduit-fittings-20511-64_1000.jpg


8

The issue is thermal... and we're fighting two completely separate types of thermal wars. The war on fire: Incandescent bulbs don't care about heat, they love it, they love being oven lights. They also create a lot of it! A 40W bulb makes 39 watts of heat and 1 watt of light. So with incandescent, the war is to keep the incandescent's heat from setting ...


8

Removing this box is not a good solution when there are rigid conduits bringing wires into this existing box. The main reason for this is that those wires would still need to terminate into an accessible junction box. On top of that there is just no simple way to adapt the existing rigid conduits for connection to the floating connection box on a recessed ...


8

You need to stop destroying stuff right now. Since your project is this light, you are assuming the universe is gracious enough to have ALL the wires in these conduits be ONLY about this light. That is a faulty assumption. There could be other circuits you don't know about; your plans could break them. Now to start with, nobody uses conduit for their ...


7

3 Way LED bulbs finally do exist now: http://store.earthled.com/products/switch-switch3-way-led-light-bulb


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