125V plugs and sockets The NEMA 1-15P (P for plug) is an unearthed 2 pin plug with flat parallel pins ¼ inch wide and ½ inch apart. Live and neutral pins each have a hole, which matches a corresponding bump on the sockets internal contact to make accidental removal more difficult. Where polarisation is required, one pin will be wider than the other; all sockets have a larger aperture for neutral so the polarised plug only fits one way round (unpolarised plugs will fit either way). The plug is rated up to 15 Amps at 125 Volts.
The socket is NEMA 1-15R (R for receptacle), but these are now rare as building regulations require a grounded connection.
The NEMA 5-15P is identical to the 1-15P with the addition of a round or U-shaped earth pin, which is 1/8 inch longer than live and neutral to make first contact with the socket outlet. The earth pin also makes the plug polarised. It is also rated 15A 125V; the mating receptacle is NEMA 5-15R, which is by far the most common socket in North America, as it accepts both 3 pin 5-15P and 2 pin 1-15P plugs.
The twist-lock reference is NEMA L5-15P and L5-15R (L for locking) which has the same current and voltage ratings, but is not compatible. These are used to prevent accidental disconnection of the mains, as the plug has to be twisted to remove it from the receptacle.
The NEMA 5-20P plug is up-rated to 20A, and has its neutral pin rotated by 90 degrees. The 5-20R receptacle has a T-shaped aperture, to accept the 5-20P along with the 15A 5-15P and 1-15P plugs. The locking versions are NEMA L5-20P and L5-20R respectively.
250V plugs and sockets The NEMA 6-15P plug is rated up to 250V 15A, and is used on 208V and 240V circuits. The live and neutral pins are in line, rather than parallel; the socket is NEMA 6-15R. The NEMA 6-20P and 6-20R are up-rated to 20A with a rotated pin, and the receptacle may have a corresponding T-shaped aperture to accept 20A and 15A plugs. These may be wired for split-phase live-live-ground (2x 125V) rather than live-neutral-ground (1x 250V). The locking plugs have the same ‘L’ prefix.
Contact our friendly technical team for more information call us on 01264 353489 or click here to contact us