anbm said:
what's the difference between switchboard and switchgear besides voltage rating and housing material? Thanks!
Switchgear is usually drawout type circuit breaker which means it is very very large compared to a switchboard. Switchgear is built to different UL/ANSI standards.
Switchboards are often use the same type of breakers that are found in "panelboards". They are often only 24-36" deep.
There are many other differences. If you are dealing with reduced down time and routine maintainability requirements (i.e. service entrance equipment for a hospital) then switchgear may be the right way to go. If you are concerned with installed costs and infrequent maintenance (i.e. an office building) then switchboards may be sufficient.