NEMA connectors are power plugs and receptacles employed for Air conditioning mains electrical power in Northern America and other countries designed to use the standards set from the US Nationwide Electric Manufacturers Association. NEMA wires gadgets come in current ratings from 15 to 60 amperes (A), with voltage rankings from 125 to 600 volts (V). Various mixtures of contact blade widths, shapes, orientations, and measurements create non-exchangeable connectors that are unique for each and every combination of voltage, electric current carrying capacity, and grounding system.
NEMA 1-15P (two-pole, no ground) and NEMA 5-15P (two-pole with ground pin) plugs are employed on typical household electric equipment, and NEMA 5-15R is the regular 15-ampere electric receptacle (outlet) found in america, and below relevant nationwide standards, in Canada (CSA C22.2 No. 42, Mexico (NMX-J-163-ANCE) and China (JIS C 8303).
Other plug and receptacle types are for unique reasons or perhaps for weighty-duty programs.
NEMA connections are known as following an alphanumeric program code composed of: prefix “L” (securing kinds), numerals, a hyphen, numerals, suffix “R” or “P” for “receptacle” or “plug”.
There are 2 fundamental categories of NEMA connectors: straight-blade and securing. The steel conductive cutting blades are often informally called “prongs” (like “3-prong plug”). Numbers prefixed by ‘L’ are curved-blade, perspective-securing connectors. Twist-locking kinds can be used for heavy commercial and commercial gear, where increased protection towards unintentional disconnection is required.
The numerals preceding the hyphen encode the number of poles (current-carrying terminals) and cables linked to it, the voltage, and single- or 3-phase energy. A connector with ground terminal is referred to as having more cables than poles, e.g. two-pole, three-wire; or four-pole, 5-wire; and so on. A non-grounding device may be two-pole, two-wire; three-pole, three-cable; and so on.
The numerals following the hyphen is the current rating in the gadget in amperes. This number is followed by the letter ‘R’ to indicate a receptacle or ‘P’ to indicate a plug.
As an example, the five-15R is definitely the common 125 V two-pole, three-wire receptacle ranked for 15 A. The L5-15R, while revealing the same electrical ranking, is a locking design which is not physically compatible with the directly-blade 5-15 design. The Five-30R provides the same two-pole, three-cable configuration and 125 V ranking, but is ranked for 30 A.
Although there are several non-grounding device types inside the NEMA specifications, only three of them are in widespread use nowadays. These are the two-pole 1-15, nevertheless in use in millions of structures built before the 1960s, and the three-pole 10-30 and 10-50.
Other kinds of NEMA connections which do not stick to this nomenclature include: the ML collection (so-known as “Midget Securing” connectors known as for their diminutive dimension), TT (for connecting travel trailers and other leisure vehicles to external power sources), SS series (“deliver-to-shore” connectors to connect watercraft to shore power) and also the FSL series (found in military services and airplane programs).
The little hole near the end in the power (low-ground) blades of some NEMA plugs is used for comfort in production; if present, it should be of specific diameter and place. Small specific padlocks are offered to match these holes, allowing “lockout” of dangerous equipment, by actually preventing insertion of secured plugs into a power receptacle. Since at the very least 1949, several receptacle devices have been invented to make use of these holes to hold the prongs within the receptacle slot machines, skocrg a corresponding latch or locking system.
The cutting blades of a NEMA connector are identified within the dimensional regular as follows: ‘G’ recognizes the grounding conductor, ‘W’ identifies the (grounded) neutral conductor, and ‘X’, ‘Y’, and ‘Z’ are the “hot” line conductors. Single-stage connectors only have one particular terminal known as ‘X’ or two terminals, ‘X’ and ‘Y’. 3-stage connectors will use ‘X’, ‘Y’ and ‘Z’.
Judgments continues to be aimed at the design leaving a space with uncovered prongs. This safety defect has been exploited by way of a Jan 2020 Web phenomenon known as the Outlet obstacle, where conductive components, usually coins or papers clips were dropped into the gap, leading to electric sparks, which once triggered a building evacuation in Westford Academy