Choosing Electrical Utility Cabinets
Choosing an electrical utility cabinet is much more than estimating the size needed. There are several important factors that should be part of the decision. Most utility cabinets will be used in industrial situations where the cabinet might be exposed to water, dust, corrosive chemicals or other unfriendly elements. The engineer tasked with specifying a cabinet should know the environment where the cabinet will live. Is a sealed unit required? Is the environment corrosive? What about wash-downs or airborne dust or lint? The engineer can consult NEMA standards to select a type to meet the requirements.
Utility Cabinets
Once a type has been selected it is time to size the cabinet. It is a good idea to create a mock-up of the components that will be inside the cabinet. It is easy to forget that there will be wiring inside the cabinet and that there will be conduits or wire troughs attached to the box as well. The physical space inside the cabinet is limited by several factors that must be kept in mind. The sub-panel where the components will be mounted is smaller than the inside dimensions of the box and the useable depth of the box is reduced by the height of the sub-panel mounts. If switches, displays or other components will be mounted on the door, the useable depth will be further diminished. This must be considered when sizing a box.
One frequently overlooked factor is heat dissipation. A cabinet must allow components enough room for air circulation because all electrical devices generate some heat. Transformers and solid-state drives can get quite hot. Some additional cooling may be required and this must be allowed for when sizing the cabinet.
Accessories and Utility Cabinets
This leads to accessories. As mentioned, auxiliary air conditioning or vortex cooling may be needed. There are door latches, lighting, and other accessories that may be required. Each manufacturer will have a set of standard equipment, options, and accessories. Shopping around to see what is available is a good way to be reminded about something that might otherwise be overlooked.
Utility cabinets are available in a myriad of sizes and configurations from a multitude of suppliers and manufacturers. They can be found in most NEMA enclosure types including type 1, type 4R and type 12. Sizes range from small (4 inches x 4 inches x 4 inches) to large stand-alone multiple door control boxes. These large cabinets can be ganged together to create machine controls several yards long. These large panels can even include climate control systems.
The styles and configurations are virtually unlimited and some manufacturers will custom build cabinets to the customer’s specifications. These are used as machine tool control cabinets and automated process control panels. In the industrial world utility cabinets are like furniture. Cabinets can be arranged to meet any need including entire operator stations. Interconnections between cabinets can be handled by NEMA type wire-ways and troughs. There is virtually no limit to the size and shape of custom-built cabinets. Materials can be painted steel, galvanized steel, stainless steel, plastic and glass reinforced polyester.
