Do you know a junction box installation of calculation made by Smart Junction Box manufacturer?

  A junction box installation of calculation made by Smart Junction Box manufacturer:

The amount of wiring box installation, the District clearly loaded, concealed, according to the size difference between the junction boxes were half the circumference of the "a" for the unit. Junction box itself is the value to be calculated separately.The amount of junction box installation, the District clearly loaded, concealed on the junction box and cable, respectively, "a" for the unit. Junction box value must be calculated. Surface mounted junction box, including junction boxes, switch boxes installed two children; concealed junction box, including both ordinary and explosion-proof junction box junction box installed two children.

Exceed the length of the wire and pipe laying, the intermediate junction box should be added: 1, the length of each pipe bend no more than 45m; 2, each more than 30m length of pipe has a bend; 3, the pipe length exceeds 20m each with 2 bend ; 4, tube length over 12m every three corners. between two junction boxes for its dark piping shall not be more than three right-angle bend, out piping shall not exceed four.