| Word | Description |
| 3-Way Switch | Electrical 3-Way Switches allow you to control one electrical source, such as a light, from 2 switch locations. Two 3-way switches would need to be wired together in order to work in unison. |
| 4-Way Switch | They are used in combination with a pair of 3 way switches to control lights from three or more locations. |
| Auto Rest Shutdown Circuit | Auto Rest Shutdown Circuit The Circuit senses the lamp life and will automatically shut off power when the lamp approaches the end of its life. When a new lamp is inserted in the socket, the ballast resets, and turns on the lamp automatically. Some shutdown circuits require the power to be interrupted before a new lamp will re-light. |
| Ballast | An electrical device used in fluorescent and HID fixtures. It furnishes the necessary starting and operating characteristics to the lamp for proper performance. |
| Ballast Efficacy Factor (BEF) | Defined as ballast factor divided by input watts. The value is used to evaluate various lighting systems based on light output and power input. The BEF can only be used to compare systems operating the same type and quantity of lamps. |
| Ballast Factor (BF) | This is the percentage of a lamp's rated lumen output that can be expected when operated on a specific, commercially available ballast. Note that the "rated output" is sometimes measured on a reference ballast unlike ones that actually operate the lamp in the field. |
| Ballast Hum | Sound generated by the vibration of laminations in the iron core of the transformer or inductor present in the ballast. |
| Ballast Losses | Power or energy dissipated in the ballast as heat and not converted to lamp energy. |
| Base or Socket | The socket is the receptacle connected to the electrical supply; the base is the end of the lamp that fits into the socket. There are many types of bases used in lamps, screw bases being the most common for incandescent and HID lamps, while bipin bases are common for linear fluorescent lamps. |
| Base Temperature (Maximum) | The maximum operating temperature permitted for the base in Celsius. Fixture manufacturers need to ensure that these conditions are satisfied in their fixture. |
| Bayonett Base | A style of bulb base which uses keyways instead of threads to connect the bulb to the fixture base. The bulb is locked in place by pushing it down and turning it clockwise. |
| Beam Angle | The angular dimension of the cone of light from reflectorized lamps (such as R and PAR types) encompassing the central part of the beam out to the angle where the intensity is 50% of maximum. The beam angle sometimes called "beam spread" is often part of the ordering code for the reflectorized lamps. Example: The 50PAR30/HIR/NFL25 is a 50 watt PAR30 narrow flood lamp with a beam angle of 25 degrees (See FIELD ANGLE). |
| Beam Lumens | The total lumens present within the portion of the beam contained in the beam angle. |
| Beam Spread (Approximate) | For reflector type lamps. The total angle of the directed beam (in degrees horizontal or vertical) to where the intensity of the beam falls to 50% or 10% of the maximum candlepower value as indicated. |
| Bi-Pin | Any base with two metal pins for electrical contact. This is the typical base for a fluorescent tube of 1 to 4 feet in length. It consists of 2 prong contacts which connect into the fixture. Medium bi-pins are used with type T-8 and T-12 tubular fluorescent lamps, and miniature bi-pins are used for tubular T-5 fluorescent lamps. Of course the Bi-Pin bulb is the standard connection for MR-16 bulbs. |
| Biax® | This is a GE trademark for GE's biaxial family of high-efficiency and long-life compact fluorescent lamps. A straight tube is bent back in the middle, constituting a biaxial tube. |
| Black Light | A popular term referring to a light source emitting mostly near UV (320 to 400 nm) and very little visible light. |
| Blacktop | Whether or not the top of the miniature lamp has a blacktop coating. The coating is used to control unwanted brightness or glare. |
| Bollard | A short, thick post with a light at its top, used for grounds and outdoor walkway lighting. |
| BTU | BTU or British Thermal Unit, is a unit of measure for heat value. The higher the BTUs a device is capable of outputting the more powerful it is. |
| Bulb | A loose way of referring to a lamp. "Bulb" refers to the outer glass bulb containing the light source. |
| Bulb Material or Coating | The type of glass (or quartz) used in the glass envelope surrounding the light source. The material can also have coatings applied to achieve particular performances. |
| Carbon Monoxide Alarm | Detect a deadly odorless gas, available as standalone or in combination with smoke alarms. |
| CFM | CFM (Cubic Feet per Minute) is the standard of measure for devices such as ventilation fans. The higher number of CFM a fan has the more air it is able to move in a given period of time. |
| Derating | All dimmers rely on heat conduction and convection to keep the electronic components cool. Derating is the reduction of the maximum capacity (load) a unit can reliably handle when fins/side sections are removed. |
| Digital timer switch | Where physical obstructions deter the use of occupancy sensors, the digital timer provides an effective means of controlling light sources and conserving energy. Most timers have various preprogrammed time allowances ranging from 10 minutes to three hours. As a safety measure, most timers offer a flashing function that quickly turns the connected lights on and off several minutes before shutting them off completely. |
| Dimmer | An electronic or manual switch that increases or reduces the amount of voltage that reaches the lamp. |
| Electronic Low-Voltage | Electronic low-voltage lighting uses an electronic (solid-state technology) transformer to convert normal line voltage (120 VAC) to low voltage (typically 12 VAC). This lower voltage is then used to power an incandescent low-voltage lamp. Only use a dimmer-amplifier specifically designed for an electronic low-voltage transformer. |
| GFCI | (Ground Fault Circuit Interrupt) A type of device, e.g. circuit breaker or receptacle, which detects an abnormal current flow to ground and opens the circuit preventing a hazardous situation. |
| Ionization Smoke Alarm | The most common smoke alarms installed in home. They are highly reliable and simple to install. |
| Magnetic Low-Voltage | Magnetic low-voltage lighting uses a magnetic (core and coil) transformer to convert normal line voltage (120 VAC) to low voltage (typically 12 VAC). This lower voltage is then used to power an incandescent low-voltage lamp. Only use a dimmer specifically designed for a magnetic low-voltage transformer. |
| Multi-Location Dimmer | Allows full-range dimming from unlimited locations. |
| Occupancy sensor switch | Occupancy sensors provide on/off control of light sources where energy management is critical. They generally incorporate two types of technology to trigger lighting fixtures: infrared and ultrasonic. Infrared sensors create a field of energy in a pattern of beams to cover a specified area. The drawback is that they require an unobstructed line of site over the area being controlled to be most efficient. On the other hand, ultrasonic sensors fill a room or area with inaudible sound, “seeing” over partitions and obstructions. The drawback to this device is that it can be too sensitive to disturbances that may occur outside its field. Current occupancy sensing devices incorporate both technologies, balancing their strengths and weaknesses in a reliable product. |
| Photoelectric Smoke Alarm | Use light inside the alarm to sound the alarm. They are less sensitive than ionization models and you will have fewer false alarms. They are great to use in kitchens where false alarms are common. |
| RMA | Return Merchandise Authorization |
| Single Gang | One control mounted in a single wall box. |
| Single-Pole Dimmer | A Dimmer in which the electrical wires only affect one (1) light and do not continue on to other Dimmers. |
| Single-Pole Switch | A switch in which the electrical wires only affect one (1) light and do not continue on to other switches or receptacles. |
| Sone | A sone is an internationally recognized measurement of sound output. Sones translate decibel readings into numbers that correspond to the way people sense volume, and follow a "linear" scale, like inches. Sone readings offer quick sound comparisons for laymen and engineers. |
| Static Pressure | Static pressure is a measure of the resistance against airflow as the fan pushes air through a duct. It is measured in inches of water column or water gauge, such as 0.25" w.g. to show that resistance is equal to a column of water gauge. It is expressed as 0.1" w.g. or 0.25" w.g. to show that the resistance is equal to a column of water one-tenth or one-quarter of an inch tall. |
| Transformer | A transformer is used to change an incoming voltage to a reduced outgoing voltage. For example a low voltage transformer will change a standard 120V to 12V for use on low-voltage devices. |
| Watt | A measure of power or the rate of energy consumption by an electrical device when it is in operation. Watts are calculated by multiplying the voltage at which an appliance operates by the current it draws (Watts = Volts X Amperes). |