Elective noise: refers to radio frequency * (RFI) and electromagnetic * (EFI) and other high-frequency *, motor operation, relay action, motor controller work, broadcast emission, microwave radiation, and electrical storms, etc., will cause noise.

Frequency variation: refers to the variation of the city power frequency more than 3 Hz, which is mainly due to the unstable operation of emergency generators, or by the frequency of unstable power supply.

Low voltage (brownout): refers to the city voltage effective value is lower than the rated value, and lasts for a long time, its causes include: large equipment start-up and application, main power line switching, starting large motor, line overload and so on.

Power fai1: refers to the situation of power interruption which lasts for at least two cycles to several hours. Its causes include circuit breaker tripping on the line, power supply interruption, power grid failure, etc.

SNMP: It is the abbreviation of Simple Network Management Protocol. Its significance is to enable computers and peripheral equipment to connect directly to the network without passing through the computer, and let the network system be managed. High-order UPS usually has an optional SNMP network management interface, which makes it easy to connect to the network.

IGBT: It is the abbreviation of Insulated Gate Bipolar Transistor in English. IGBT is a kind of power crystal. The UPS designed with this kind of crystal can effectively improve the efficiency of the product. It has many advantages such as good quality, high efficiency, low heat loss, low noise, small size and long life of the product.

Isolation transformer: refers to the equipment and general UPS when used together, often because of the electrical characteristics of zero ground voltage, resulting in equipment* or misoperation and other issues. In order to avoid this situation, some high-order UPS is designed to solve this problem. With special design, the output zero-ground voltage can be less than 1 volt to avoid the above problems. In addition, it has the function of noise filtering.

AVR: It's the English abbreviation of Automatic Voltage Regulation. AVR is the meaning of automatic voltage adjustment, that is, UPS adjusts the number of coil turns of the input voltage through the internal output transformer or processes power electronic components to achieve UPS has a wide range of power input and stable output voltage characteristics.

Power supply adjustment rate: the output voltage stability accuracy when the input changes.

Communication protocol: The rules that interconnected devices abide by when exchanging data.

SNMP: English abbreviation of Simple Network Management Protocol (SNMP), which is mainly used for monitoring, fault inquiry and control of TCP/IP network, and provides a simple network management protocol for user data programming.

Input Frequency Range: The standard frequency of China's power grid is 50Hz. UPS allows a certain range of changes in the city power frequency. Within this range, UPS synchronously tracks the city power frequency and outputs it at the local frequency when it exceeds it.