Liquid crystal display. A readout device in which each digit is formed by strips of a liquid-crystal material. The crystal material is normally transparent, but becomes opaque when an electrical field is applied to it, and transparent again when the field is removed. Because no light is produced, LCDs are difficult to read in dim light unless backlit.

Light emitting diode. A specialized diode that sends out light when biased in a forward direction. Forward bias means that the anode is positive with respect to the cathode. When used as a display, LEDs do not require a back light, since they generate their own light.

Abbreviation for the constant voltage and frequency AC power line.

line noise reduction kit
Used on the input of a drive when other equipment on the same AC power line as the drive is very sensitive to irregularities in the power that is provided to it. A major part of the kit is a set of inductors which restrict any rapid changes in the current delivered to the drive. The kit may also include capacitors that limit the rate of voltage change.

line notching
A very quick short duration change in the AC power line voltage caused by the switching of power components in the input section of an adjustable frequency drive (as well as other devices). The depth of the notch, in volts or percent, and the area of the notch, in V-Ás, are used to measure the severity of the notch.

linear acceleration/deceleration
A circuit in the drive that sets a uniform rate at which the motor is allowed to accelerate/decelerate. The rate of acceleration/deceleration is usually adjustable.

locked rotor current
The steady state current taken by the motor from the line when the rotor is not allowed to rotate.