- T-Slots are used in aluminum or vinyl windows, used as a frame or sash seal in casement windows, or on the meeting rail of double and single hung windows.
- 20 Amp White Decora T-Slot Receptacle Item: # 3665-046 Model: # 6352W-BU; Order Online. FREE SHIPPING to a store near you. Add To Cart Save To List.
- 20-amp receptacles have a horizontal slot branching off one of the vertical slots. Appliances, such as microwaves, often have 20-amp plugs and must be plugged into a 20-amp outlet. Electrical plugs designated as 20-amp will not fit into 15-amp outlets.
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.
• • • • • • • • • • • • • • • • • • • • • • • • • • •
The reason why its called a 't-shaped neutral' is because, as you can see in the photo above, the neutral is the larger of the two inputs and it has a slot sticking out of it that shapes it into a T. This makes it easy to spot when you are on a location/tech scout. 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.
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?
• What is the requirement for a service receptacle outlet for heating, air conditioning, and refrigeration (HACR) equipment?
• 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?
• Why does painting an electric receptacle (outlet) make it unsafe?
• Why are electrical outlets and plugs polarized?
• How many electrical receptacles (outlets) are required in a hallway?
T Slot Duplex Receptacle
• What problems does having too many electric receptacle outlets on a single circuit cause?
• Is a house required to have outdoor electric receptacle outlets?
• 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?
• Is an ungrounded electric receptacle outlet dangerous?
• My bathroom electric receptacle/outlet is dead and there are no tripped breakers in the electric panel. What's wrong?
• Is there an adapter that can be placed on a two-slot receptacle to make it safe?
• How do the new tamper-resistant electric outlets work?
• Why is there no bathroom electric receptacle in this old house?
• How can I tell if the electric receptacle outlets are grounded?
• How far apart should the electrical receptacles be placed?
• What are the most common problems/defects found with electric receptacle outlets during a home inspection?
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.
How To Look At A House
McGarry and Madsen's home inspection blog for buyers of
site-built, mobile/manfuactured and modular homes
Click Below
for Links
• 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?
• Why does painting an electric receptacle (outlet) make it unsafe?
• Why are electrical outlets and plugs polarized?
• How many electrical receptacles (outlets) are required in a hallway?
T Slot Duplex Receptacle
• What problems does having too many electric receptacle outlets on a single circuit cause?
• Is a house required to have outdoor electric receptacle outlets?
• 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?
• Is an ungrounded electric receptacle outlet dangerous?
• My bathroom electric receptacle/outlet is dead and there are no tripped breakers in the electric panel. What's wrong?
• Is there an adapter that can be placed on a two-slot receptacle to make it safe?
• How do the new tamper-resistant electric outlets work?
• Why is there no bathroom electric receptacle in this old house?
• How can I tell if the electric receptacle outlets are grounded?
• How far apart should the electrical receptacles be placed?
• What are the most common problems/defects found with electric receptacle outlets during a home inspection?
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.
How To Look At A House
McGarry and Madsen's home inspection blog for buyers of
site-built, mobile/manfuactured and modular homes
Click Below
for Links
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