IEEE C57.148-2011 pdf download IEEE Standard for Control Cabinets for PowerTransformers
4.Cabinet-ordering specificationsThis standard includes requirements that are intended to provide a basic, standard design. This standardalso provides options on many aspects of the design and construction. Additionally, the user may specifyand require other options. A sample ordering form is included in Annex B to provide a convenient andcomplcte method of communicating the purchaser’s sclection of standard design, standard options or uscrsoptions for all aspects of the control cabinet.
5.Standard cabinet construction
5.1 General
The following standard cabinet construction requirements shall apply to all control cabinets covered underthis standard.
Note that references herein to the National Electric Code”(NEC”) (NFPA 70″) are not intended to includethe complete NEC as a normative reference. All references to the NEC in this standard are specific to thctopic covered in the clauses containing the references only, and any other NEC requirements not referencedin this document do not apply to control cabinets covered under this standard.
5.2 Cabinet-housing criteria
Unless specified otherwise, the complete cabinet shall be constructed for outdoor use to meet or exceed theNEMA 3R designation as detailed in NEMA 250.
For special application environments such as corrosive or chemical atospheres. marine or explosion proolrequirements, the appropriate NEMA or IEC designations shall be specified by the user. The NEMA Typeperformance requirements are defined in NEMA 250 “Enclosures for Electrical Equipment (1000 VoltsMaximum)” The IEC designations are defined in EC 60529 “Degrecs of Protection Provided byEnclosures(IP)”
Cabinets with gross weight greater than 20 kg (44.1 lb) shall have provisions for lifting and a sufficientnumber of external tabs for the purpose of bolting to the transformer. Additional external brackets formounting gauges shall be specified by the transformer manufacturer or user
Cabinet mounting provisions must meet the specified requirements of the user or supplier, respectively.depending on who orders the cabinetthe manufacturer. One such requirement is the ability toaccommodate vibration suppressors or similar mounting hardware. Unless specified otherwise by the useror supplier, the control cabinet designer should design the cabinet to be mounted on the transformer withnot less than a 200 mm (7.9 in) air space between the back of the cabinet and the transformer tank wall
5.3 Cabinet dimensions
Cabinet height and depth shall be such that all switches, circuit breakers, fuses, device display panels, and allsimilar components that require operation, adjustment, or inspection during normal operation can becomfortably reached by a person of average height (approximately 1.7 m, or 5 ft 7 in) when standing at theplane of the door. The mounted location of the control cabinet should be determined by the supplier basedon user specifications, transformer foundation design, shipping limitations, and other considerations. Unlessotherwise specified by the user, the bottom of the control cabinet shall not be less than 0.5 m (19.7 in) above