NEMA connector: Difference between revisions

== Precedents ==

{{Main|History of AC power plugs and sockets}}

 

=== Harvey Hubbell's inventions ===

 

==== Other American manufacturers ====

 

=== NEMA ===

 

==Nomenclature==

[[File:NEMA simplified pins.svg|thumb|350px|alt="Row and column table of NEMA receptacles."|NEMA receptacles, with their common US uses listed (in purple text)]]

 

 

 

As an example, the 5-15R is the common 125 V two-pole, three-wire receptacle rated for 15 A. The L5-15R, while sharing the same electrical rating, is a locking design that is not physically compatible with the straight-blade 5-15 design. The 5-30R has the same two-pole, three-wire configuration and 125 V rating, but is rated for 30 A.

Other types of NEMA connectors that do not follow this nomenclature include: the ML series (so-called "Midget Locking" connectors named for their diminutive size), TT (for connecting [[travel trailers]] and other [[recreational vehicles]] to external power sources), SS series ("ship-to-shore" connectors for connecting boats to [[shore power]]) and the FSL series (used in military and aircraft applications).

 

 

The blades of a NEMA connector are identified within the dimensional standard as follows: 'G' identifies the grounding conductor, 'W' identifies the (grounded) neutral conductor, and 'X', 'Y', and 'Z' are the "hot" line conductors. Single-phase connectors have only a single terminal identified as 'X' or two terminals, 'X' and 'Y'. Three-phase connectors will use 'X', 'Y' and 'Z'.<ref name="WD6"/>

Criticism has been aimed{{By whom|date=October 2021}} at the design leaving a gap with exposed prongs. This safety flaw has been exploited by a January 2020 [[Internet phenomenon]] known as the ''[[Outlet challenge]]'', where conductive materials, usually coins or paper clips were dropped into the gap, causing [[electric spark]]s, which once led to a building [[Emergency evacuation|evacuation]] in [[Westford Academy]].<ref>{{cite web |last1=Lee |first1=Bruce Y. |title=What Is The 'Outlet Challenge'? How It Can Electrocute Or Burn You |url=https://www.forbes.com/sites/brucelee/2020/02/23/what-is-the-outlet-challenge-how-it-can-electrocute-or-burn-you/ |website=Forbes |language=en |date=2020-02-23}}</ref><ref>{{cite web |title=Dangerous TikTok Challenge Sparks Warning From Firefighters |url=https://www.nbcboston.com/news/local/fire-officials-warn-parents-about-outlet-challenge/2065446/ |website=NBC Boston |date=2020-01-21}}</ref><ref>{{cite news |title=Authorities warn about dangerous TikTok 'outlet' challenge |url=https://abcnews.go.com/US/authorities-warn-dangerous-tiktok-outlet-challenge/story?id=68531391 |access-date=5 November 2020 |work=ABC News |date=2020-01-25 |language=en}}</ref>

{{anchor|Receptacle chart}}<!-- Shorter, more convenient, anchor -->

{| class="wikitable" style="text-align: center;"

|+NEMA Receptacle chart (non-twist lock)<ref name=WD6/>

!125 V

!1

|''5-20R''

|''5-30R''

| colspan="2" | -

| colspan="2" | -

!2

|''6-15R''

| colspan="2" | -

| colspan="2" | -

!125 V

!5

| colspan="2" | -

| colspan="2" | -

!250 V

!6

| colspan="2" | -

| colspan="2" | -

!277 V

!7

| colspan="2" | -

| colspan="2" | -

!10

| colspan="2" | -

| colspan="2" | -

| colspan="2" | -

250 V

!11

| colspan="2" | -

| colspan="2" | -

!125/ 250 V

!14

| colspan="2" | -

| colspan="2" | -

250 V

!15

| colspan="2" | -

| colspan="2" | -

120/ 208 V

!18

| colspan="2" | -

| colspan="2" | -

! no !! yes !! no !! yes !! no !! yes !! no !! yes

|-

| 120&nbsp;V || [[#NEMA_1|1]]; [[#ML|ML1]] || [[#NEMA_5|5]]; [[#NEMA_TT-30|TT]];

[[#SS|SS1]]; [[#ML|ML2]]

| 240&nbsp;V || - || 25

|-

| 240&nbsp;V (split-phase)<br />208&nbsp;V (wye) || [[#NEMA_2|2]] || [[#NEMA_6|6]]

| 480&nbsp;V || - || [[#NEMA_8|8]]

| 415&nbsp;V || - || -

|-

| 120/240&nbsp;V (split-

phase)<br />120/208&nbsp;V (wye)

| 240/415&nbsp;V || - || -

|-

| 240&nbsp;V (delta)<br />208&nbsp;V (wye) || [[#NEMA_11|11]] || [[#NEMA_15|15]]

| 480&nbsp;V || [[#NEMA_12|12]] || [[#NEMA_16|16]]

| 415&nbsp;V || - || -

|-

| 120/208&nbsp;V || [[#NEMA_18|18]] || [[#NEMA_21|21]]

| 277/480&nbsp;V || [[#NEMA_19|19]] || [[#NEMA_22|22]]

In [[stage lighting]] for film and theater, this connector is sometimes informally known as ''PBG'' (''Parallel Blade with Ground''), ''U-ground'', ''Edison'' or ''Hubbell'', the name of a common manufacturer.<ref>Drew Campbell ''Technical Film and Tv for Nontechnical People'', Skyhorse Publishing Inc., 2002 {{ISBN|1581159986}} Chapter 9</ref> (The name "Hubbell" can be confusing as several different connectors share this name depending on the company, industry, and use.) In the motion picture and TV production industries, an extension cord that uses this type of connector (usually with 12 AWG or 10 AWG wire)<ref name="tftv">{{cite book|last=Campbell|first=Drew|title=Technical Film and TV for Nontechnical People|publisher=Allworth|year=2002|page=133|isbn=1-58115-229-9|url=https://books.google.com/books?id=CARrSo742ycC|access-date=2010-02-16}}</ref> is called a "stinger".{{citation needed|date=November 2013}} Generally, [[lighting technician]]s use these extension cords to deliver power to lights rated at 2,000&nbsp;watts or less.<ref name="slth">{{cite book|last=Box|first=Harry C.|title=Set Lighting Technician's Handbook: Film Lighting Equipment, Practice, and Electrical Distribution|publisher=Focal|year=2003|edition=3rd|page=20|isbn=0-240-80495-3|url=https://books.google.com/books?id=EfUlyxSlBYMC|access-date=2010-02-16}}</ref>

 

 

===NEMA 6===

 

===NEMA 14===

 

All NEMA 14 devices offer two hots, a neutral, and a ground, allowing for both 120 and 240&nbsp;V when supplied by [[Split-phase electric power|split-phase power]], or 120 and 208&nbsp;V if the supply is [[three-phase electric power|three-phase]]. The 14-30 has a rating of 30&nbsp;A, and an L-shaped neutral blade. The 14-50 has a rating of 50&nbsp;A, and a straight neutral blade sized so that it does not mate with 14-30 connectors.

 

 

{{gallery|width=150 |height=150|align=center

 

===Leak-current detection and interruption (LCDI) cordsets===

 

==Color code==