DC Power Distribution Systems
DC power distribution systems are used to take the output from a power supply system and facilitate the connection to the load(s). Although each one is unique, over the years Kepco has found that using a series of proven common building blocks allows greater flexibility for custom tailoring to a particular application and environment, while maintaining high quality and reliability of the system. |
Typically, output power from the power system is divided to facilitate physical connections to the load. For example, a 21 Ampere redundant power system (two or more 21 Ampere power supplies) may be connected to ten loads drawing 1 Ampere, and 1 load drawing 10 Amperes. The distribution system provides the mechanical and electrical components necessary to connect the wires from the load to the DC bus. A DC distribution system for this example could be accomplished with a 22 position barrier strip: two positions (+ an -) for each of 11 loads.
Among the building blocks Kepco typically uses to accomplish this are
Protective DevicesProtective devices may be used either on the entire DC bus, or on individual branches that go to each load. In the example above, there may be ten 1 Ampere and one 10 Ampere fuse circuits. Examples of the Protective device building blocks used in Kepco power distribution systems are circuit breakers as well as various types of fuses, including American style, indicating style, and Telco indicating style.
Low Voltage DisconnectsA low voltage disconnect is used when there is a battery floated across the DC bus. If AC fails, the battery powers the load and as the battery discharges, the voltage decays. If the voltage drops below a certain point, the battery will be destroyed, so to prevent this, the low voltage disconnect (generally, a normally open relay or contactor) is wired between the battery and the load. When the voltage drops to a predetermined level, the relay opens. When AC is restored, the power supply turns on, the disconnect closes and the load is run from the power supply while the battery is recharged.