A dual power supply system draws power from two separate sources, utilizing two distinct power lines. Because the power sources are different, the dual power supply systems can operate independently of each other. A dual power supply refers to drawing power from two sources of different nature, with two feeder lines, one active and one standby. If the "one active, one standby" refers to the power sources, then it is a dual power supply. This means that if one power source fails, the second one will not fail simultaneously, which can meet the power supply requirements of Class I and Class II loads.
Common application scenarios for a dual power supply: Important party, government, and military organizations, national defense, and key scientific research projects, where a power interruption would cause severe consequences. Important news and broadcasting centers, transportation and communication hubs, public utilities, and healthcare facilities, where a power interruption would cause severe consequences. Military industrial units, factories, and enterprises where a power interruption would cause personal injury and equipment accidents, significant material loss, massive product spoilage, production stoppage, and prolonged inability to resume operations. Important public venues. Units with special requirements for the continuity of the power supply based on the characteristics of their production.
A dual-loop power supply system refers to two lines of the same voltage originating from two separate substations or two bays (or sections) of a single substation. When one line fails due to a fault, the other line can be immediately switched into use. This is often used in schools, enterprises, and public institutions for convenience and speed. If the "one active, one standby" refers to the feeder lines, it cannot be called a dual power supply. A dual power supply is generally more reliable than a dual-loop supply, but for a single building, the two may appear similar, and in many cases, both involve two incoming lines.
A dual-loop power supply is a system where a single load has two power supply circuits. The dual-loop supply method can be a dual power, dual-loop supply, or a single power, dual-loop supply. In the case of a single power, dual-loop supply, the power supply to the entire load will be interrupted if the main power source or busbar fails.
The power sources for a dual-loop supply can be the same or different. They can operate independently or in conjunction. When one line in a loop sourced from a different power supply fails, the other standby loop can immediately be put into operation to supply power to the equipment. A dual-loop power supply refers to two lines of the same voltage coming from two substations or two bays of one substation, and the "one active, one standby" here refers to the feeder lines, not the power sources.
Therefore, the "loop" in "dual-loop" refers to the circuit coming out of the regional substation. A dual power supply means the power sources are different and mutually independent, so that if one fails, the second one will not fail at the same time, meeting the requirements for Class I and Class II loads. In contrast, a dual loop generally refers to the end-user side, where if one line fails, the other standby loop is put into operation to supply power to the equipment. The two loops can be from the same power source or different power sources.
Dual-loop power supply is mainly used for Class II loads with relatively high power requirements, such as hospitals and banks. In line design, two power supply loops are often provided. If the power source in one loop fails, the power in the other loop can effectively ensure the continuity and reliability of the electricity use. Thus, a dual power supply is fed by two independent power sources, while a dual-loop supply can have one or two power sources. The point of confusion is that "when one power source fails or is required, it can be switched to the other power source for supply" in both cases. In terms of power guarantee requirements, the dual power supply is primarily used for the higher-demand Class I loads.