Network installation is low voltage application, you don't have to licenced to do the job, any handy man or decoration 師傅will do.
However, since you are a business and you want to bring power to the back of the LCD mon. Legally you need a lisenced ELECTRICIAN to do the job.
For myself at home I just open an opening in the wall and fish / feed the an armour power cable to thebottom of the wall whereas the power jack located. |