Cable tray support quantity can be calculated using a simple formula: Support Quantity = Total Length ÷ Support Spacing + 1 20 ÷ 2 + 1 = 11 supports In a typical project, a 20-meter cable tray with 2-meter spacing requires 11 supports. Although BS 7671 touches on the subject of cable supports, it does not detail specifically what these support distances should be. 8 (Other Mechanical Stresses (AJ)) in that document provides requirements for cable support. Clause 522-08-04 Where conductors or cables are not supported. cable trays are equivalent. The mechanical and electrical characteristics, tests, certifications, overall quality management, recommendations mentioned in this technical guide only apply to our own cable management ranges and cannot under any circumstances be transposed to si osure, overheating or. The MKS and SKS cable tray systems from OBO Bet-termann have a long tradition. For 45 years, the ro-bust systems, which have been tested for various areas of application, have been successfully em-ployed by planners and specialists in the field of elec-trical installations. With our many years of experience, we are one of the leading manufacturers in this field. Nuclear plants follow NRC Regulatory Guide 1.