Safety becomes a significant design factor when an object requires either direct human interaction, uses inherently dangerous materials, or incorporates motion/kinetic movement into it. Two critical safety issues that must be addressed in the Lamp Project are electricity and heat. Although energy efficiency is not a safety factor, it is a requirement of the project.
Electricity is the primary energy source for indoor lighting fixtures. In the USA, the standard voltage for duplex outlets is 120V. The amperage that flows through that voltage on a standard outlet is 15A. This amount of power is enough to cause serious damage to your body. In some countries, double that voltage is used. Volts and Amps have an inverse relationship. 120V@15A is the same amount of energy as 240v@7.5A. Suffice it to say, there is a lot to this. If you are interested in more information about the fascinating subject of electricity, I encourage you to do your own further research.
I have personally been shocked by 120V, 15A circuits on several occasions, and indeed it is not a fun experience. In fact, it is difficult to describe; a sort of rapid vibrating energy that seems unreal. If you gripped a live electrical wire that has a high enough current you may not be able to let go. It is called tetanic contraction. Luckily, I have only barely touched a live household circuit through my fingers or arms. It is possible to be killed if the electricity disrupts the electrical rhythm of your heart. Higher amperages can certainly kill instantly with fiery, explosive results.
Commercial lamp fixtures and shades are made from many different materials and methods designed to keep you safe. Materials serve the purpose of efficiently transmitting electrical current into a light bulb while also protecting the user from electrical shock. Metals are electrically conductive, as is water and many liquids. Wood and most plastics are generally non-conductive, as are ceramics and glass. Some metals are extremely good conductors and some are very poor. Copper, for example, is an excellent conductor. It is used as the primary conducting material in our homes. Although wood is a very poor conductor, it burns easily, thus is a bad choice of insulator. Ceramic and glass are superior insulators, and are not flammable; they also melt at very high temperatures. Certain plastics insulate very well, and are in common use as insulators, though they can melt fairly easily. Plastics can also burn. The way to keep plastics from failing is to keep the electrical current cool, which is done by making solid wire connections and by drawing low amounts of power through the wire.
Structural or decorative metals in stands, sockets and shades must be isolated from the electrical system, and grounded if possible. Grounding essentially means that the electricity path will travel back to the earth. The middle hole on a household outlet is for a ground conductor. Normally, no electricity travels through that conductor, except in emergencies. A grounded object that is shorted will conduct electricity away from you, and may be able to safely trip a breaker. Ungrounded lighting fixtures are common, and the standard for household lamps. This requires extra design care to avoid a short. You can tell that a lamp is ungrounded if the cord has two prongs on the end. If it has three, it is grounded.
A short is when electrical current flows improperly though an unintended part of the system. In low levels of short, this can result in wasted electricity. In higher levels: electric shock, heat buildup, arcing, ignition, tripping of breakers and even has the potential to shut down an entire electrical grid.
With the above in mind, the Lamp Project utilizes commercially available lamp swag kits that are designed and manufactured to be safe when used properly. We also use LED bulbs because they are very efficient. The swag kit includes, the ungrounded plug end, 15' of insulated conducting wire, and an insulated socket capable of securing to a thin material via the threaded ring.
Heat buildup, and risk of fire is a major concern in lighting. Even when using properly built and maintained parts, heat is generated when electricity is used. The swag kits are designed for normal heat dissipation from LED and fluorescent light bulbs. Flammable materials must either be chemically treated or otherwise safeguarded from the bulb's heat. If possible, non-flammable materials should be employed.
Metals are typically non-flammable, though there are some notable exceptions. Magnesium is somewhat conductive and very flammable. It is so flammable and intense when burned that it is used to make road flares. Although metals such as steel, copper and aluminum are non-flammable, they conduct heat extremely well. This is why a piece of metal that is cooler than your body will feel cold to the touch, even when it is the exact same temperature as a piece of fabric that feels warm. And that same piece of metal when hotter than your body will feel like it is burning you even when it is the same temperature as a piece of wood that feels pleasant to the touch. Metal will dissipate heat from a lamp, but also risks causing a mild burn.
The best way to avoid heat in a lamp fixture is through efficient energy use. LED bulbs only get warm. Fluorescent bulbs get hotter, and incandescent bulbs become blisteringly and dangerously hot.
The following section on Synskin is important information, but we cannot use the material due to the pandemic. We will discuss alternative materials later.
Use of low-flammability or non-flammable materials for the shade is imperative. We employ Synskin for the shades because it has several useful properties. First, it is made from glass fibers, which is not conductive, and does not burn. Its melting temperature is very high. Second, it has a fibrous structure, and air can pass through it, helping carry heat out of the enclosure through convection.
Although the fiberglass in Synskin is coated with a vinyl binder, the binder is self-extinguishing; this means that in the absence of a continuous heat source, a flame will not sustain itself and will go out. Also, even with all of the vinyl burned away, the fiberglass still holds its structure. I have demonstrated this by placing a piece of Synskin in the path of a propane torch. If I hold the flame directly on the Synskin, the vinyl burns. If I remove it from the path of the torch, the vinyl extinguishes. If I leave the Synskin in continuous contact with the propane flame, all of the vinyl will burn away and the fiberglass will begin to glow red, but the heat is not high enough to melt the glass. The fiber structure stays intact.
LED bulbs are preferred over fluorescent and incandescent bulbs because they: use far less electricity for the quantity of light, last longer, produce less heat, and are not made from brittle glass. Unlike fluorescent light bulbs, LEDs do not contain toxic mercury.
The filaments in an incandescent light bulb emits light only because it is extremely hot. It reaches a temperature of approximately 4600 ยบ Fahrenheit. LEDs creater light differently, but they do produce heat to some degree. The amountof heat eminating from an LED can vary greatly based upon design, so the rules of lamp safety described here still must be adhered to.
Because lighting manufacturers have traditionally designed fixtures and shades with incandescent light bulbs in mind, standard lamp shade distances are listed below. These numbers are from the filament to the shade, and are industry standards. Since your lamp requires the use of an LED bulb, which emits far less heat than incandescent, following these guidelines ensures a very high margin of safety.
