NEMA connectors are power plugs and receptacles utilized for Air conditioning mains electrical power in Northern America and other countries designed to use the specifications set by the US National Electric Manufacturers Association. NEMA wiring devices come in current rankings from 15 to 60 amperes (A), with voltage rankings from 125 to 600 volts (V). Various mixtures of contact blade widths, designs, orientations, and measurements create non-interchangeable connectors which are unique for each combination of voltage, electric current carrying capability, and grounding system.
NEMA 1-15P (two-pole, no ground) and NEMA 5-15P (two-pole with ground pin) plugs are used on common domestic electric gear, and NEMA 5-15R is definitely the standard 15-ampere electrical receptacle (electric outlet) found in the United States, and under appropriate national specifications, in Canada (CSA C22.2 No. 42, Mexico (NMX-J-163-ANCE) and China (JIS C 8303).
Other plug and receptacle kinds are for unique reasons or heavy-responsibility applications.
NEMA connections are named following an alphanumeric program code composed of: prefix “L” (locking types), numerals, a hyphen, numerals, suffix “R” or “P” for “receptacle” or “plug”.
There are two basic classifications of NEMA connectors: directly-blade and locking. The metal conductive cutting blades are often informally called “prongs” (as with “3-prong plug”). Numbers prefixed by ‘L’ are curved-blade, twist-locking connectors. Twist-locking kinds can be used as weighty commercial and industrial equipment, where improved protection towards accidental disconnection is needed.
The numerals preceding the hyphen encode the number of poles (current-transporting terminals) and wires attached to it, the voltage, and single- or three-stage energy. A connector with ground terminal is referred to as having much more wires than poles, e.g. two-pole, three-wire; or 4-pole, five-wire; and so on. A low-grounding device may be two-pole, two-cable; three-pole, 3-wire; and so on.
The numerals following the hyphen is the current ranking in the gadget in amperes. This number is then the letter ‘R’ to suggest a receptacle or ‘P’ to indicate a plug.
For example, the 5-15R is definitely the common 125 V two-pole, 3-wire receptacle ranked for 15 A. The L5-15R, while revealing the same electrical ranking, is a securing design that is certainly not actually appropriate for the straight-blade 5-15 design. The 5-30R has the exact same two-pole, three-wire configuration and 125 V rating, but is rated for 30 A.
Even though there are numerous non-grounding device kinds within the NEMA specifications, only 3 seem to be in prevalent use today. These are the basic two-pole 1-15, still being used in countless structures built before the 1960s, and also the 3-pole 10-30 and 10-50.
Other sorts of NEMA connections that do not follow this nomenclature include: the ML series (so-called “Midget Securing” connectors named for small size), TT (to connect journey trailers and other leisure vehicles to exterior power resources), SS collection (“deliver-to-shore” connections for connecting watercraft to shoreline energy) and also the FSL collection (used in military services and airplane programs).
The small opening close to the finish of the energy (non-ground) cutting blades of some NEMA plugs is used for convenience in production; if present, it ought to be of specified diameter and position. Small specific padlocks are available to fit these openings, enabling “lockout” of hazardous equipment, by physically stopping placement of locked plugs in to a energy receptacle. Since at the very least 1949, numerous receptacle gadgets are also created to make use of these openings to hold the prongs within the receptacle slot machines, skocrg a corresponding latch or securing system.
The cutting blades of any NEMA connector are identified within the dimensional regular the following: ‘G’ identifies the grounding conductor, ‘W’ identifies the (grounded) neutral conductor, and ‘X’, ‘Y’, and ‘Z’ are definitely the “hot” line conductors. Single-stage connectors have only just one terminal recognized as ‘X’ or two terminals, ‘X’ and ‘Y’. 3-stage connections uses ‘X’, ‘Y’ and ‘Z’.
Criticism has been aimed at the design departing a space with uncovered prongs. This safety flaw has been exploited by a January 2020 Web trend referred to as Electric outlet obstacle, where conductive materials, generally coins or papers clips were dropped into the gap, leading to electric sets off, which as soon as resulted in a building evacuation in Westford Academy