Wattage refers to the amount of power drawn by the light bulbs, so it has a direct impact on the type and number of bulbs that you can control with a dimmer switch. “To determine the appropriate wattage capacity for a dimmer switch, calculate the total wattage of the bulbs it will control,” says Jason Brady, owner of Above and Beyond Service Company. “For example, if you have five 60-watt bulbs, the total wattage is 300 watts.” You can then select a dimmer switch that’s capable of handling over 300 watts, because it’s important to leave a safety margin. Trailing edge dimmer switches have a much lower load than leading edge and inductive dimming modes. This is no longer a concern with the zero minimum load of the V-PRo. The Varilight V-Pro contains both trailing edge and a modified leading edge mode in one, these modes can also be programmed. On initial startup, the V-Pro will initialise itself and adapt to the exact LEDs that are on the circuit. Programming only needs to be done to fine tune the dimming results if required. By adding additional Leviton Decora Smart Dimmer Companion switches, you can set up virtual 3-way, 4-way, or even 5-way control over your lights. The primary switch has to be wired to the lights like a traditional dimmer, but the companion switch can be placed anywhere and doesn’t need to be connected to the main switch by physical wires. The connection is achieved wirelessly through your Wi-Fi network, so you do need to have Wi-Fi to use this kit. It works with Alexa, Google Assistant, and Apple HomeKit, so you can also use it to operate and dim your lights through an app on your phone or voice commands. Dimmers allow you to achieve the exact light level that you desire in a room and consequently alter the mood. There are various types of dimming options available, but the most popular are ‘phase control’ (or phase-cut) dimmers. Phase control dimmers work by chopping out parts of the voltage and reducing power to the light source. The two types of phase control dimmer available are ‘trailing-edge’ and ‘leading-edge’ and they work in different ways which ultimately affects their compatibility with certain light forms:

For an increased chance of compatibility, trailing-edge dimmer switches tend to work better with the capacitive load of an LED driver. The Varilight V-Pro LED Dimmer 1 x 300Wis from the award-winning V-Pro range. It has an industry-wide reputation for delivering one of the best LED dimming performances available. Research & Investment The popularity of trailing edge dimmers today has surpassed that of leading edge dimmers. The reason is because of its advantages over leading edge dimmers like smoother dimming control, soft start, silent running, or the absence of any buzzing noise when in operation, less interference and is ideal for use in most premises. Trailing-edge: capacitive loads (e.g. electronic low voltage transformers, LED drivers), resistive loads (e.g. incandescent). When using trailing edge dimmers with LED, it is very important to remember the 10% rule. So, if you have a 400W trailing-edge dimmer, it can easily power 400W incandescent lamps. But with LEDs, the maximum load is only 10%, which means that the maximum load would only be 40W worth of LEDs. Advantages of Trailing Edge Dimmers Leading-edge dimmer switches are cheaper and simpler than trailing-edge, and were used originally to dim incandescent and halogen bulbs or wirewound magnetic transformers. They use a ‘TRIAC’ (Triode for Alternating Current) switch to control power, and are sometimes called TRIAC dimmers.Additionally dimmer switches work within a certain operational load range. If your dimmer switch has a range of 0 to 400W, it is possible to have 10 lamps each having 40W on it, or you can have 8 lamps each having 50W. You can have any combination as long as it adds up to a maximum of 400W. LED Lights and Dimmers Trailing edge dimmers are dimmers used typically with electronic drivers. With this type of dimmer, voltage and current are not rushed to the light source. Compared to leading-edge dimmers, trailing edge dimmers have a low minimum load. It then becomes a better choice for dimming low-powered lighting circuits. This is why they work best with LEDs. There are two types of dimmer systems that you can have in your home – trailing edge and leading edge. All of our bulbs and ceiling kits are suitable for trailing edge dimmers only. There are no 4-way dimmer switches, but this kit from Leviton is functionally what you’re looking for if your goal is to operate and dim your lights from three or more locations. The reason 4-way dimmers aren’t possible with traditional switches is due to the way that light switch circuits work, and this kit gets around that problem by not using a traditional light switch circuit. Instead, it uses a primary switch, a companion switch, and a plug-in bridge unit that allows them to connect wirelessly. The most important requirement when installing a dimmer switch is a neutral wire, because a lot of modern dimmers require a neutral wire. Homes built prior to 1985 typically won’t have a neutral wire unless the wiring has been updated and brought up to code, so this is an important consideration.

Unlike incandescent bulbs, which are all dimmable by default, LED retrofit bulbs have a built-in driver in their base. The driver converts AC power to DC power and maintains a constant current to the LED. This is at odds with a phase control dimming system, since the driver attempts to compensate for the sliced-out portions of input voltage. This article was written by Jeremy Laukkonen, a freelance writer for The Spruce. Laukkonen has more than a decade of experience writing about and reviewing consumer technology. He prefers smart light switches and bulbs, because who has time these days to operate the lights manually? His writing has also appeared in Digital Trends, Lifewire, and Entertainment Weekly. For trailing edge circuits, when using LED bulbs, the maximum wattage is 10% of your circuits maximum load. For example, if your trailing edge dimmer system’s maximum load is 300W for incandescent bulbs, it would be 30W when using LEDs. This can be spread across multiple lights on one circuit. Many existing leading-edge dimmer switches have a relatively high minimum load, which often rules out their use with modest LED or CFL lighting circuits. However, leading-edge dimmers are by far the most common dimming control in existence. Trailing-edge Dimmers (Reverse phase dimmers)Toggle: These look like standard toggle light switches, but you can raise and lower the toggle to dim and brighten your lights instead of flipping on and off in two binary positions like you would with a traditional light switch. In other cases, the toggle itself acts as an on/off switch, and you adjust the illumination level with a very small slider that’s located right next to the toggle. These are best for applications where you won’t need to adjust the illumination level every day. The Cloudy Bay in Wall Dimmer Switch for LED Lights is a toggle switch with a small dimming slider, and it functions in both single pole and 3-way installations. The dimming slider is a little on the small side, but it doesn’t get in the way of the switch. It’s fully compatible with all Cloudy Bay LED light fixtures right out of the box, and it also includes a trim dial that allows you to adjust it to work well with other fixtures and dimmable LED bulbs. It comes with everything you need to complete the installation, including screws, wire nuts, and even a decorative wall plate. A trailing-edge dimmer has a lower minimum load than leading-edge dimmers, making it a better choice for dimming modestly sized low-powered lighting circuits. LED lights and dimming However, as well as the above, there are also other differences between the two types of dimmers… Leading-edge dimmers (TRIAC dimmers) Additionally, Sampayo points out that determining how many LED lights you can put on a single dimmer switch is a little complicated. “LEDs have a high current spike when switched on, and this varies among manufacturers. So, the rule is: Don't count the watts directly!” Instead, Sampayo recommends multiplying the total wattage of the LED bulbs by 7, adding a safety margin of 20 percent, and then selecting a switch that meets or exceeds those requirements.

Smart home integration can provide you with a lot of options that aren’t available from a traditional dimmer switch. “Smart switches have gained popularity in the era of home automation,” says Brady. “They can be controlled remotely and integrated into smart home systems.” If that sounds interesting, then you may want to consider a smart dimmer. Brady cautions that it's important to pay special attention to compatibility, as smart dimmers are typically designed to work with smart home systems. Dimmers aren’t all about setting the mood though, and Sampayo says installing them in your home can save you money, too. “Practically speaking, the human eye can't distinguish between 90 percent and 100 percent light brightness, but your energy bill can,” Sampayo advises. “Being conscious of energy consumption means you could set your lights to never exceed 90 percent, ensuring a 10 percent energy saving without compromising on brightness.” If you're looking for smartphone controlled or voice activated lighting, the Lightwave Smart Series is a great choice. Their easy to use App allows you to dim, switch, set scenes and timer functions. You can combine actions for multiple lights at the touch of just one button. Analogue Dimming 0-10V For example, the Kasa HS220, our best smart dimmer, works with Alexa and Google Home, but not with HomeKit. If your smart home is powered by Apple’s HomeKit, you’ll find that the Kasa HS220 just won’t work correctly. In that case, consider the very similar Kasa KS220 that works with HomeKit. If you do have more than 10 LEDs, we've also got the V-Pro high wattage dimmers which will dim up to 30 LEDs with a maximum of 300W. Or the Varilight V-COM series which will dim up to 60 LEDs with a maximum of 600W. These higher wattage dimmers are also useful for dimming longer runs of LED tape with.

How to avoid LED dimmer compatibility issues

Adding a dimmer switch to a lighting setup, or replacing an old one with a newer model, can transform the look and feel of a room. “Dimmers are most useful in areas where you want to create ambiances, such as social areas, bedrooms, hallways, and bathrooms,” says Freddy Sampayo, chief technology officer of Schaller Tech. “It's also useful to think about spaces where you'd be annoyed to turn on the light when waking up groggily in the middle of the night.” Leading edge dimmer switches can buzz slightly as they operate on TRIAC and contain a small transformer with a coil. If you're just dimming a few LED lamps or downlights, don't get caught up too much with the technicalities of trailing edge vs leading as V-Pro will work out of the box. Because of its energy efficiency and long lifespan, LED lights are often the smartest choice for your home. If you want to create mood lighting and get the most of your LED lights you should use a phase cutting dimmer. This is the most popular among dimming control devices. The voltage rating of a dimmer switch tells you where you can use it. For example, residential electrical voltage in the United States is 110 - 120VAC. That means you can use any 110 or 120V dimmer switch in your home.

Tap: This type of dimmer uses a tap control to switch the lights on and off, and then another method to adjust the illumination. Traditional dimmers are only designed to work with incandescent lights, although some also work with halogen, while LED dimmers are designed specifically for LED bulbs. “Traditional dimmers, which typically use knobs, usually absorb the energy not sent to the light,” says Sampayo. “For instance, if you dim your light to 30 percent, the remaining 70 percent is wasted by the regular dimmer in the form of heat. Your energy consumption remains at 100 percent.” That works with incandescent lights that exhibit reduced brightness when provided with less energy, but LED bulbs placed in that same situation won’t light at all, or may exhibit unwanted behaviors.Choosing an LED compatible dimmer switch used to be difficult and a bit of a lottery. This was because dimming technology differs from LED to LED and the wattage is much lower than incandescent. Varilight solved this problem many moons ago with their V-Pro series of LED compatible dimmer switches.