What should I know before I build a junction box for multiple rooms and a bathroom fan?

Answer by  surajit (101)

Basically you have to know about the AC current and the most important thing is to identify the phase and neutral of AC current. To built the junction box first properly install the switch for different connection make sure that all connection are made from junction box to any appliance (bathroom fan) are in parallel.

Answer by  Brandon55 (1719)

If you are feeding the box from a single source, consider the total amount of current you would likely draw. Typical wiring is 20 to 30 amps maximum.