Voltage | Current | type | Name | Notes |
120 VAC | 15 amp | straight blade | NEMA 5-15 | Std grounded wall plug with straight shaped neutral hole |
120 VAC | 20 amp | straight blade | NEMA 5-20 | Std grounded wall plug with T-shaped neutral hole |
120 VAC | 30 amp | straight blade | NEMA 5-30 | Std grounded wall plug with L-shaped neutral |
208 VAC | 15 amp | locking | L6-15 | wall plug with blades turned 90deg, (horizontal) |
208 VAC | 20 amp | locking | L6-20 | blades turned 90deg, with T-shaped neutral hole |
208 VAC | 30 amp | locking | L6-30 | blades turned 90deg, with L-shaped neutral hole |
Generally BSOE specs NEMA 5-20 outlets for new construction when possible. NEMA 5-30 should be replaced with locking type plugs when used. Higher power, such as 208 VAC outlets should also be specified with locking type plugs when possible. Locking plugs give a higher degree of safety since it becomes harder to inadvertently pull the plug from the receptacle.
Straight Bladed 120 & 208/240 volt connectors
http://www.stayonline.com/reference-nema-straight-blade.aspx
From Sun - lists some standard 208/240VAC connections
http://sunsolve.sun.com/handbook_private/Devices/Wiring_Dgms/WIR_AC_Power.html
Wikipedia NEMA Electrical Connector Info
http://en.wikipedia.org/wiki/NEMA_connector