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A rating plate on a machine carries information about its operational limits. The plate frequently contains the names of the machine and its manufacturer, so the rating plate is often called a
A rating plate on a machine carries information about its operational limits. The plate frequently contains the names of the machine and its manufacturer, so the rating plate is often called a name plate
A nameplate identifies and displays a person or product's name. Nameplates are usually shaped as rectangles but are also seen in other shapes, sometimes taking on the shape of someone's written name. Nameplates primarily serve an informat ...
(hence the term " nameplate capacity" for a generator), although many devices carry separate nameplates and rating plates.
For an electric machine
Electricity is the set of physical phenomena associated with the presence and motion of matter possessing an electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as described by ...
, the power rating is the number on its rating plate and corresponds to a maximum electric load it can carry. There is a distinction between the ''continuous rating'' (for generators, continuous maximum rating or CMR), at which the machine can be operational without a time limit and short-term rating that can only be used for a specified amount of time.
Generators
A typical electrical generator rating plate contains the following parameters: * ''power rating'' is specified in terms ofapparent power
In an electric circuit, instantaneous power is the time rate of flow of energy past a given point of the circuit. In alternating current circuits, energy storage elements such as inductors and capacitors may result in periodic reversals of the d ...
(KVA or MVA), since the exact power factor will be determined by the external factors;
* ''power factor'' (PF) is the nominal power factor for other ratings; usually PF = 0.8;
* '' insulation class'' (B, F, H) for the primary coil. Typical value is F, although older generators might use class B;
* ''type of enclosure'' (IP code
The IP code or International Protection code indicates how well a device is protected against water and dust. It is defined by the International Electrotechnical Commission (IEC) under the international standard IEC 60529 which classifies ...
);
* rated voltage can be either line to line (" line voltage") or phase to neutral (" phase voltage");
* rated current is derived from the rated power and voltage: ;
* '' line frequency'' (50 Hz or 60 Hz) and rotational speed of the prime mover in RPM;
* ''connection'' ( star or delta).
See also
* Per-unit systemReferences
Sources
* Electric power systems components {{Electric-power-stub