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NEMA L12 series devices are three-pole, three-wire, non-grounding devices for three-phase 480-volt devices. Designs exist for 20-ampere (L12-20), and 30-ampere (L12-30) devices, and L12-20 and L12-30 devices were commercially available from at least one manufacturer (Bryant Electric).
A three-phase induction motor has a simple design, inherently high starting torque and high efficiency. Such motors are applied in industry for many applications. A three-phase motor is more compact and less costly than a single-phase motor of the same voltage class and rating, and single-phase AC motors above 10 hp (7.5 kW) are uncommon. Three ...
Today, microprocessor-based relays can perform many protective functions in one device. [1] When one device performs several protective functions, it is typically denoted "11" by the standard as a "Multifunction Device", but ANSI Device Numbers are still used in documentation like single-line diagrams or schematics to indicate which specific ...
NEMA contact ratings are how much current at a rated voltage a relay or other pilot device can switch. The current rating of smaller NEMA contactors or their auxiliaries are defined by NEMA ICS 5: Industrial Control and Systems, Control Circuit and Pilot Devices [1] standard. The nomenclature is a letter followed by a three-digit number, the ...
NEMA (National Electrical Manufacturers Association) contactors and motor starters are rated by sizes. These sizes are grouped by rated current and power . [ 1 ] [ 2 ]
An American Rotary Phase Converter with a Transformer. A phase converter is a device that converts electric power provided as single phase to multiple phase or vice versa. The majority of phase converters are used to produce three-phase electric power from a single-phase source, thus allowing the operation of three-phase equipment at a site that only has single-phase electrical service.
In electrical engineering, three-phase electric power systems have at least three conductors carrying alternating voltages that are offset in time by one-third of the period. A three-phase system may be arranged in delta (∆) or star (Y) (also denoted as wye in some areas, as symbolically it is similar to the letter 'Y').
Three-prong plugs do not fit into the older, two-prong receptacles. [7] When used as intended, the ground pin of the 3-wire receptacle is to be connected to a grounded cover screw, or to an external ground. In 1969, Underwriters Laboratories mandated three-prong plugs on major appliances for safety. [7]