BS 787-2 is a British standard that specifies requirements for mining type flameproof gate-end boxes with air-break circuit-breakers for use on 3-phase a.c. circuits up to 650 volts. BS 787-2 has been prepared to standardize the main features of gate-end boxes used primarily in coal mining in the United Kingdom.
It is recognized that the term “gate-end box” is quite general and may be applied to boxes containing different essential components, such as contactors, circuit-breakers, lighting transformers, etc., depending upon the purpose for which they are to be used.
BS 787-2 on gate-end boxes with air-break circuit-breakers is useful for:
A flameproof container meant to connect up with similar boxes to form a control board, primarily for usage at or near the coalface. For the management of motors, lighting, and other equipment, a gate-end box may contain bus bars, isolators, switches, contactors, transformers, and protective devices. An air circuit breaker is used to safeguard low-voltage circuits by energizing and de-energizing high currents.
BS 787-2 provides its users with guidelines for the marking, design, and construction and addresses the instructions for conducting tests for assessment of performance and efficiency.
Using BS 787-2 guidelines ensures safety and protection, efficiency, quality assurance, and reliability for longer service life.