How To Look At A House
McGarry and Madsen's home inspection blog for buyers of
site-built, mobile/manufactured and modular homes
Why do some receptacle outlets have a T-shaped hole?
Sunday, August 23, 2020
The T-shaped slot indicates that the 120-volt receptacle is rated for 20-amps. Regular wall receptacles with a pair of vertical slots are rated for only 15-amps, but the T-shape enables it to accept either a 15- or 20-amp plug.
This receptacle configuration is called a NEMA 5-20R, a standard created by the National Electrical Manufacturers Association, and it accepts a NEMA 5-20P plug like the one shown below.
• • • • • • • • • • • • • • • • • • • • • • • • • • •
To learn more about electrical wiring, devices, and receptacles, see these other blog posts:
• What is the difference between what trips a GFCI (ground fault) receptacle and a circuit breaker?
• What is the code requirement for GFCI protection for receptacles near a wet bar sink?
• Why is an opening in the wall around the side of an electrical receptacle outlet a safety defect?
• When was GFCI-protection for kitchen dishwasher receptacle outlet first required?
• What is allowable voltage range at a wall receptacle outlet in a house?
• When should I replace electric receptacle outlets?
• Does an electric receptacle outlet in a storage shed require GFCI protection?
• What are "self-contained" electrical receptacle outlets and switches?
• What is the difference between an electrical receptacle, an outlet, and a plug?
• Does a washing machine receptacle outlet require GFCI protection?
• What is the building code requirement for receptacle outlets at stairs and stair landings?
• Can I remove a 240-volt range receptacle and hard-wire the range?
• What is a "backstab" receptacle outlet?
• Why are some electric receptacle outlets upside down (ground slot up) in a house?
• What is the height requirement for an electric receptacle outlet?
• Where are GFCI receptacle outlets required?
• When were GFCI receptacle outlets first required?
• Does a home inspector remove receptacle outlet cover plates?
• What is the minimum height for an exterior receptacle outlet?
• When was the current receptacle/outlet spacing of 12-feet first required?
• When was the three-slot (grounding) outlet/receptacle first required?
• How I can tell if a receptacle outlet is tamper resistant?
• Why is there a GFCI breaker in the electric panel for the bathroom shower light and exhaust fan?
• What is a false ground, bootleg ground, or cheated ground receptacle?
• How can adding wood paneling or a wainscot create an electrical safety hazard?
• How can I figure out what a mystery wall switch does?
• How far apart should kitchen counter receptacles be spaced?
• How far above a kitchen countertop do electrical outlets have to be?
• What is reversed polarity at an outlet/receptacle? Why is it dangerous?
• How high above the floor do electric outlets/receptacles in a garage have to be?
• How far apart should electric receptacles be spaced in a bathroom?
Visit our ELECTRICAL page for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles.
Click Below
for Links
to Collections
of Blog Posts
by Subject
Top 5 results given instantly.
Click on magnifying glass
for all search results.
Search
This
Site
Buying a home in North/Central Florida? Check our price for a team inspection by two FL-licensed contractors and inspectors. Over 8,500 inspections completed in 20+ years. In a hurry? We will get it done for you.
