Efficiency (EFF) Efficiency is the ratio of energy output to energy input, such as the ratio between the electrical energy input to a motor and the mechanical energy output at the shaft of the motor.
效率 效率是输出能量与输入能量的比率，例如输入到电动机的电能与电机轴承输出的机械能的之间的比率。

Emergency System An emergency system is independent power generation equipment that is legally required to feed equipment or systems whose failure may present a life safety hazard to persons or property.
应急系统 应急系统是指根据相关法规要求，为那些可能会危及生命安全或造成财产重大损失的设备或系统提供电源的独立发电设备。

Energy Energy is manifest in forms such as electricity, heat, light and the capacity to do work. It is convertible from one form to another, such as in a generator set, which converts rotating mechanical energy into electrical energy. Typical units of energy are kW/h, Btu (British thermal unit), Hp/h, ft/lbf, joule and calorie.
能量 能量以电能、热能、光能等形式存在，可以做功，也可以从一种形式转换为另一种形式，例如发电机组能把机械能转变为电能。经常用的能量单位有： 千瓦/小时、英国热量单位、马力/小时、焦耳、卡等。