Enclosure (electrical)

A cabinet houses the electrical and electronic components of a process plant, a machine tool or production facility that is not directly in the machine ( eg sensors ) are located.

Design and Manufacture

In the simplest case it contains only terminals for clear electrically connecting various components of a system (terminal box, distribution box ). In a closed cabinet, the random and accidental contact with live parts is excluded; Cabinets that contained in the interior accessible parts with hazardous voltages, are with tools (control panel key, three- or four- socket key ) to open.

It is produced at standard sizes by cabinet manufacturer or special designs also by the machine manufacturer itself, the internal construction takes place in an electrical workshop. The finished cabinet has plug connections (power, media), so it can be delivered as a transport unit.

Function

The following functions to an empty enclosures provide the electrical and electronic equipment:

  • For the components in the interior: Protection against dust and water spray (protection, IP protection class according to DIN EN 60529)
  • Support and structuring of the internal structure (eg DIN rails, mounting plate, subdivision in power and control areas )
  • Protection against overheating ( cabinet air conditioning )
  • Protection from Electromagnetic Interference (EMI )
  • Protection against mechanical damage, vandalism and earthquakes (cabinets with additional braces )
  • Shielding electromagnetic emissions
  • Protection against contact with hazardous voltages ( class ratings: Grounding or protective isolation)
  • Fire protection ( special solutions for smoke extraction )

Some cabinets have a window for reading / detection of switching states and the measured values.

Many cabinets have outside an emergency stop button and / or a suitable main switch for the decommissioning of the associated machine in case of emergency, shut off the machine for service.

Types

Switch cabinets - depending on the application - from painted sheet steel, made ​​of plastic ( eg outdoor installation ) or aluminum sheet.

Standard color for painted cabinets is currently RAL 7035 (light gray), after previously RAL 7032 ( pebble gray ) was used.

For corrosive environments, as well as pharmaceutical and food companies also made ​​of stainless steel cabinets are made that are not painted in the rule.

The following types are common:

  • Stand- cabinet: Single detached housing with one or two doors, often with wheels
  • Baying cabinet: individual elements without side panels, cables and wires can be internally embarrassed about the elements of time. At the ends of the screwed-together walls panels can be attached. In modern Anreihschaltschränken can be used for cable laying, the floor-standing front post remove.
  • Terminal box (any mount)
  • Wall housing (wall mounting)
  • With inner swivel frame to allow additional mounting surfaces for better use of space available

Cabinets are also available with pre-assembled or supplied additional components:

  • Fans, filter fans, air intakes ( vents, grilles or a remote roof)
  • Heat exchanger
  • Cooling units ( allow cooling in dense housing)
  • Interior lighting
  • Feet or castors

Other options include, for example, Castles and transparent doors.

Dimensions

Typical of cabinets are the following sizes

Stand cabinet

In the appropriate combinations.

  • 800 x 600 x 300 mm Closet
  • 1200 x 800 mm x 300 Closet

Frequently own cabinets with widths of 600 mm inner lateral threaded lugs or carrier for insertion of cage nuts for the insertion of 19 -inch racks or racks. Such cabinets are also called rack.

Appliance classes Punch-down block
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