VA rating of Wall receptacle
The link below explains the default rated (180VA) receptacles.

http://www.tpub.com/celec/34.htm


  All receptacles used in industrial areas have to be computed at 180 VA per outlet. One exception to this rule involves the use of multioutlet assemblies (prefabricated, wall-mounted outlet strips). The load for outlet strips is to be computed at 180 VA for every 5 feet of assembly. If the outlet strip will be heavily loaded with portable tools, such as bench grinders, drill presses, soldering irons, and so forth, a load of 180 VA per foot is to be computed.