What is MSD, MSD MSD functions of battery system
what MSD is
MSD refers to all directions. The definition for liquid and gas molecules will not stay in a fixed position, but not stop moving. MSD all azimuth shift amount corresponding relationship with the atomic diffusion coefficient. MSD English full name: ManualServiceDisconnect; Chinese name: manual maintenance switch. MSD's main functions: to protect the electric vehicle maintenance technical personnel in a high-pressure environment safety of emergencies or strain, can quick separation of high voltage circuit connection, make the maintenance work for a state of relatively safe, such as external short circuit protection, maintenance need to disconnect when high pressure.
the basic principle of MSD battery system
the basic principle of MSD: MSD design in the main loop of the Pack, the built-in high-voltage fuse, and high pressure interlock function. In the external short circuit when the fuse to cut off the high voltage circuit; Need to manually disconnect when high pressure, high pressure interlock switch off, and then disconnect the high-voltage circuit. The design requirements of MSD should also include the use of temperature range, load cutting ability, resistance to chemical corrosion, mechanical strength reliability function requirements, etc.
MSD battery system of MSD functions
a, meet the refractory
MSD besides the fuse of the material is plastic material, must guarantee the MSD materials meet the fire resistance rating UL94V0. New national standard fire tests, 130 s, if MSD is not fireproof, external fire from MSD to Pack, the refractory conditions cannot be satisfactory.
2, meet the IP grade
MSD installation generally installed on the box cover, in order to ensure that satisfy IP67 or IP6k9k Pack, MSD itself must satisfy the IP67 and IP6k9k, while selecting a MSD, need to consider this as a basic parameters, require suppliers to provide validation reports. If conditional word, first to vibration of MSD components, after vibration in IP67 or IP6k9k test, in this way can guarantee the parts in the pack IP reliability of the entire life cycle.
3, meet the IP protection
MSD in connection, make sure IPxxd, disconnect when meet, IPxxb this question is easy to ignore. Does not meet the IPxxb, means that the fingers can come into contact with the high risk components, it is not allowed.
4, can be directly manually disconnect
MSD design must ensure that don't need any tools manually disconnect can be realized, and the disconnected, connect the number of at least 20 times, the actual demand is far greater than the number of times ( Could reach 500 times)