Handshaking: In computer communication, when two devices start to communicate, they must understand each other's status and the methods used. If the status of the two devices does not match, the computer will inform the user of the relevant information.

Grounding: In a power system, besides the live wire (HOTLINE) and the neutral wire (NEUTRAL LINE), the round-headed pin in the middle is the so-called grounding pin. Its function of grounding is not only to conduct some residual current or noise* into the ground, but also, and most importantly, to protect users from electric shock, especially in UPS systems. Some UPS systems will indicate the voltage between the neutral wire and the ground wire to ensure that the product will not cause electric shock damage to the human body.

Grounding and Grounding Resistance: Various computers and communication devices have grounding wires that are connected to the main grounding wire in the computer room or power distribution room, known as the earth wire. Grounding involves using a common grounding wire to connect various circuits to the ground, in order to prevent noise from affecting the operation of the equipment and to avoid potential damage to computer equipment. The better the conductivity of the earth wire to the ground, the better the grounding effect. Grounding resistance reflects conductivity, and the lower the grounding resistance, the better the conductivity.

Joule: The fundamental unit of energy, representing the energy required to move an object 1 meter with a force of 1 newton. This is referred to as 1 joule.

Poor contact: Refers to the situation where there is looseness or poor contact at the connection part of an electrical appliance. Poor contact will lead to a decrease in voltage and an increase in loss.

Transistor: It has three pins, typically labeled B, E, and C. A small current signal is applied between B and E, which can alter the current flowing between E and C, serving as a current valve and current amplifier. Transistors are current-driven devices.

Insulation resistance: refers to the degree of electrical isolation between the internal components of a device or between the circuit and the casing, usually expressed in insulation resistance.

Static switch: A device composed of thyristors, used for switching or switching compensation, capable of achieving zero (0ms) transition.

Reliability (MTBF): A parameter used to describe the average length of time that a device can operate normally. The larger the MTBF, the longer the lifespan of the device.

Ground Loop: Inside a computer, there are numerous sockets or data transmission cables, as well as other frequently used areas, all equipped with grounding wires that connect to other grounding wires, forming what is known as a "ground loop". Its purpose is to utilize a common grounding method to channel excess feedback current and noise from the circuit into the ground, thereby preventing circuit and data disruptions. Furthermore, the ground loop also serves to channel any noise lurking within the system into the ground, reducing damage caused by noise to the computer.

Reliability (MTBF): A parameter used to describe the average length of time that a device can operate normally. The larger the MTBF, the longer the lifespan of the device.

Air switch: A current protection device that trips when the current exceeds the rated value of the air switch. Air switches prevent fires caused by overcurrent in building wiring or electronic equipment wiring.

The efficiency and safety of a transformer are crucial and depend on the materials used and the manufacturing process.

2. The transformer itself has a heat dissipation issue, so the ventilation of the power supply equipment must not be obstructed.

Power-on surge current: The capacitors inside the rectifier will absorb a large charging current at the moment of power-on, the cathode ray tube (CRT) requires a large demagnetization current at the moment of power-on, the transformer has an excitation current at the moment of power-on, and so on, making the UPS have to withstand a huge surge current when the load equipment is powered on.

Fuseless switch: A current protection device, i.e., when the current exceeds the rated value of the fuseless switch (BREAKRT: commonly known as a fuse switch or circuit breaker in households), the BREAKER will immediately trip. If the rated value of BRESKER is exceeded, it can cause overheating of the wiring or electronic equipment wiring inside the building, leading to a fire.

Periodic load: A type of load device that can be quickly installed or removed.

Inverter (DC/AC): It is a converter that converts direct current (DC) into alternating current (AC). In UPS, the inverter is used to convert the energy from the battery into AC power for AC loads. Inverters vary in performance, and the output AC waveform can be either stepped wave or sine wave (SINEWAVE). The distortion factor (THD) also varies depending on the performance of the inverter.

Voltage resistance: Refers to the maximum voltage that can be withstood between the non-live parts (such as the casing and panel) and the live parts of a device. Exceeding the voltage resistance can lead to breakdown. Insulation and voltage resistance are crucial for personnel safety.

Cold start: Refers to starting a UPS when there is no mains power available, and some UPSs cannot be turned on at this time.