the u of the cabinet means height, 1U=4.45cm ..
Rack unit is the unit used by American Electronics Industry Association (EIA) to calibrate computer room equipment such as servers and network switches. A rack unit is actually 44.45 mm in height, 1.75 inches in width and 19 inches in width.
one rack unit is generally called "1U", two rack units are called "2U", and so on.
U is a unit representing the external dimensions of a server, which is the abbreviation of unit. The reason why the size of the server is specified is to keep the server in an appropriate size so that it can be placed on an iron or aluminum rack. There are screw holes for fixing the servers on the rack, so that it can be numbered with the screw holes of the servers, and then fixed with screws to facilitate the space required for installing each server.
extended information
the server cabinet has requirements on the depth, height and load bearing of the cabinet. The height is 2.2m, 2.m, 1.8m, 1.6m, 1.4m, 1.2m, 1m, etc. The width is 8mm, 7mm or 6mm; The depth is 8mm, 9mm and 1 mm.
it can be configured with: special fixed tray, special sliding tray, power bracket, floor caster, anchor nail, wire arranging ring, wire arranging bracket, L bracket, expansion beam, etc. The main frame, front and rear doors and left and right side doors can be quickly disassembled.
fixed pallet: it is used to install all kinds of equipment. It has a wide range of sizes and uses, including 19 "standard pallets and non-standard fixed pallets. The depth of fixed tray in conventional configuration is 44mm, 48mm, 58mm and 62mm. The bearing capacity of the fixed tray is not less than 5KG.
sliding tray: used for installing keyboards and other devices, which can be easily pulled out and pushed back; The 19 "standard sliding tray is suitable for any 19" standard cabinet. The depth of sliding tray with conventional configuration has two specifications: 4mm and 48 mm. The bearing capacity of the sliding tray is not less than 2KG.
power distribution unit: optional power socket, suitable for any standard power plug, with 19 "mounting rack, and flexible installation methods. Specification: 6 sockets. Parameters: ~22V, 1Amp.
cable organizer: 19 "standard cable organizer. Can be used with any kind of TOPER series cabinets. 12-hole wiring rack with 12-port, 24-port and 48-port distribution frames has the best effect.
cable management ring: a cable management device specially used for TOPER 18 series and TOPER Server series cabinets. It is very convenient to install and disassemble, and the number and position used can be adjusted at will.
Baidu encyclopedia-u (rack size)
Baidu encyclopedia-cabinet