GB/T 15395-1994General technical specification for cabinets of electronic equipment (English PDF)

1 Subject matter and scope

This standard specifies the classification and marking, design and manufacturing requirements, test methods and inspection rules for cabinets of electronic equipment.

This standard applies to cabinets of various structural forms for ground-based, vehicle-mounted, shipborne and airborne electronic equipment such as radar, monitoring and control, communication and computer equipment.

2 Normative references

GB 191, Packaging - Pictorial marking for handling of goods

GB 1184, Form and position tolerances - Tolerances without indication

GB 2423.1, Basic environmental testing procedures for electric and electronic products - Test A: Cold

GB 2423.2, Basic environmental testing procedures for electric and electronic products - Test B: Dry heat

GB 2423.3, Basic environmental testing procedures for electric and electronic products - Test Ca: Damp heat, steady state

GB 2423.5, Basic environmental testing procedures for electric and electronic products - Test Ea: Shock

GB 2423.10, Basic environmental testing procedures for electric and electronic products - Test Fc: Vibration (sinusoidal)

GB 2423.16, Basic environmental testing procedures for electric and electronic products - Test J: Mould growth

GB 2423.17, Basic environmental testing procedures for electric and electronic products - Test Ka: Salt mist

GB 3047.2, Basic dimension series of panels, racks and cabinets

GJB 4.2 to GJB 4.11, Environmental testing of shipboard electronic equipment - High temperature, low temperature, damp heat, vibration, bump, shock, mould and salt mist tests

GJB 100, Basic dimension series of panels, racks and cabinets

3 Classification and marking

3.1 Classification: according to the environment of use, cabinets are classified as ground, vehicle-mounted, shipborne and airborne cabinets.

3.2 Marking: the classification codes are given in Table 1: ground DJ, vehicle-mounted CJ, shipborne HJ, airborne KJ. Example: a ground cabinet 520 mm wide, 1600 mm high and 600 mm deep is marked DJ 520 x 1600 x 600 GB/T 15395.

4 Technical requirements

4.1 The design and manufacture of the cabinet shall meet the user's requirements.

4.2 The main structural dimensions of the cabinet shall comply with GB 3047.2 or GJB 100.

4.3 The perpendicularity of the cabinet frame to the bottom datum plane and the parallelism between frame uprights shall comply with GB 1184, with an accuracy not lower than class C.

4.4 The cabinet shall be designed and manufactured for good interchangeability and universality; products of the same model and size shall be interchangeable.

4.7 Ventilation and heat dissipation shall be considered according to the environment of use and the reliability requirements. Natural cooling shall be used as far as possible; forced air, water or other cooling may be used only where natural cooling cannot meet the requirements. Vents, louvres and exhaust openings shall be protected against sand and dust, insects and rodents.

4.12 The cabinet shall meet the earthing requirements. In general, the DC bonding resistance at the earthing lead-out shall not exceed 10 milliohm.

4.17 All mechanical connections of parts and components shall be firm and reliable; after the environmental tests no cracks, loosening, displacement or corrosion are permitted, and detachable connections shall be easy to take apart.

4.22 The environmental adaptability of cabinets is given in Table 2.

5 Test methods

5.1 Initial inspection: the cabinet is inspected according to 4.1, 4.2, 4.3, 4.4, 4.6, 4.7, 4.9, 4.10, 4.12, 4.13, 4.14, 4.15, 4.16 and 4.17 with general measuring tools (or visually) and general instruments.

5.2 Low temperature test: carried out in accordance with Test Aa of GB 2423.1 (cold test for non-heat-dissipating specimens with sudden change of temperature) or GJB 4.3, with the temperature and duration chosen according to Table 2. After recovery under standard atmospheric conditions (15 °C to 35 °C, relative humidity 45% to 75%, air pressure 86 kPa to 106 kPa), the cabinet shall comply with 4.3, 4.4, 4.12, 4.13, 4.14, 4.15 and 4.17.

6 Inspection rules

6.1 Acceptance inspection: every cabinet submitted is inspected according to 4.3, 4.4, 4.12, 4.13, 4.14, 4.15, 4.16 and 4.17. A cabinet with a nonconforming item may be resubmitted after repair by the manufacturer.

6.2 Routine inspection: in series production, samples are drawn at random each year from the first batch that has passed acceptance inspection, in the numbers of Table 3 (batch of 5 to 20: 2 samples; 21 to 100: 4; over 100: 8), and tested in the order 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9 and 5.10.