Outlets with a T-shaped hole could either be a 20A 125V variant (known as NEMA 5-20R) or a 20A 250V one (also called NEMA 6-20R). You'll know which is which by looking at the orientation of the ...

The National Electrical Manufacturers Association (NEMA) has published ANSI/NEMA CC 1 -2009 Electric Power Connection for Substations. The standard was produced by NEMA's Electrical Connector Section, ...

The National Electrical Manufacturers Association (NEMA) recently published NEMA OS 3-2012, "Selection and Installation Guidelines for Electrical Outlet Boxes." Guidelines for selection and ...