Posted By David Thomas you will find the requirements are laid down in BS7671 (IEE Wiring Regulations), which is overlooked (or even unknown) by many people in Health & Safety and also Facilities Management. A commercial building requires regular "periodic" inspections as to the suitability of the installed circuits. Over even a short period of time a circuit can easily shift from low use to high use just by moving one piece of machinery or several workstations. We are now so used to "plug and play" that we rarely think about overloading a circuit. Further details, including copies of the forms used can be found at http://www.iee.org/Publish/WireRegs/Forms_2004.pdf best regards dave