Three phase Distribution Boards require an electrician with adequate training and understand of 3-phase electricity and components

1Roof electricians have the correct parts available to replace burned out isolators or fuses, circuit breakers, ground leakage protection units and so on.

INFORMATION ABOUT LIGHTNING STRIKES
In electrical engineering, three–phase electric power systems have at least three conductors carrying alternating current voltages that are offset in time by one-third of the period. A three–phase system may be arranged in delta (∆) or star (Y) (also denoted as wye in some areas).
[SOURCE: https://en.wikipedia.org/wiki/Three-phase]

How many volts is 3-phase?: The voltage betwee two line is called line voltage . 3 phase system is expressed with line voltages. The line votage is 440 volt. Also the voltage between any one phase and neutral for a 3 phase system is 240 volts.
[SOURCE: https://www.youth4work.com/Talent/Electrical-Engineering/Forum/112741-single-phase-line-called-240v-while-3-phase-440v-why]