Utilization categories
Encyclopedia
In electrical engineering
utilization categories are defined by IEC standards and indicate the type of electrical load and duty cycle
of the loads to ease selection of contactors and relays.
Electrical engineering
Electrical engineering is a field of engineering that generally deals with the study and application of electricity, electronics and electromagnetism. The field first became an identifiable occupation in the late nineteenth century after commercialization of the electric telegraph and electrical...
utilization categories are defined by IEC standards and indicate the type of electrical load and duty cycle
Duty cycle
In engineering, the duty cycle of a machine or system is the time that it spends in an active state as a fraction of the total time under consideration....
of the loads to ease selection of contactors and relays.
| Utilization Category | Type of Application |
|---|---|
| AC-1 | Non-inductive Electromagnetic induction Electromagnetic induction is the production of an electric current across a conductor moving through a magnetic field. It underlies the operation of generators, transformers, induction motors, electric motors, synchronous motors, and solenoids.... or slightly inductive loads, example: resistive Electrical resistance The electrical resistance of an electrical element is the opposition to the passage of an electric current through that element; the inverse quantity is electrical conductance, the ease at which an electric current passes. Electrical resistance shares some conceptual parallels with the mechanical... furnaces, heaters |
| AC-2 | Slip-ring motors Slip ring motor A slip ring motor or wound-rotor motor is a type of induction motor. The rotor windings are connected to a slip ring, connected to external resistances, which allows controlling the speed/torque characteristic of the motor... : switching off |
| AC-3 | Squirrel-cage motors: starting, switches off motors during running time |
| AC-4 | Squirrel-cage motors: starting, plugging, inching |
| AC-5a | Switching of discharge lamps Gas-discharge lamp Gas-discharge lamps are a family of artificial light sources that generate light by sending an electrical discharge through an ionized gas, i.e. a plasma. The character of the gas discharge critically depends on the frequency or modulation of the current: see the entry on a frequency classification... |
| AC-5b | Switching of incandescent lamps Incandescent light bulb The incandescent light bulb, incandescent lamp or incandescent light globe makes light by heating a metal filament wire to a high temperature until it glows. The hot filament is protected from air by a glass bulb that is filled with inert gas or evacuated. In a halogen lamp, a chemical process... |
| AC-6a | Switching of transfomers |
| AC-6b | Switching of capacitor Capacitor A capacitor is a passive two-terminal electrical component used to store energy in an electric field. The forms of practical capacitors vary widely, but all contain at least two electrical conductors separated by a dielectric ; for example, one common construction consists of metal foils separated... banks |
| AC-7a | Slightly inductive loads in household appliances: examples: mixers, blenders |
| AC-7b | Motor-loads for household appliances: examples: fans, central vacuum |
| AC-8a | Hermetic refrigerant compressor motor control with manual resetting overloads |
| AC-8b | Hermetic refrigerant compressor motor control with automatic resetting overloads |
| AC-12 | Control of resisitive loads and solid state loads with opto-coupler isolation Opto-isolator In electronics, an opto-isolator, also called an optocoupler, photocoupler, or optical isolator, is "an electronic device designed to transfer electrical signals by utilizing light waves to provide coupling with electrical isolation between its input and output"... |
| AC-13 | Control of solid state loads with transformer isolation |
| AC-14 | Control of small electromagnetic Electromagnetism Electromagnetism is one of the four fundamental interactions in nature. The other three are the strong interaction, the weak interaction and gravitation... loads |
| AC-15 | Control of A.C. Alternating current In alternating current the movement of electric charge periodically reverses direction. In direct current , the flow of electric charge is only in one direction.... electromagnetic loads |
| AC-20 | Connecting and disconnecting under no-load conditions |
| AC-21 | Switching of resistive loads, including moderate loads |
| AC-22 | Switching of mixed resistive and inductive loads, including moderate overloads |
| AC-23 | Switching of motor Electric motor An electric motor converts electrical energy into mechanical energy.Most electric motors operate through the interaction of magnetic fields and current-carrying conductors to generate force... loads or other highly inductive loads |
| A | Protection of circuits, with no rated short-time withstand current |
| B | Protection of circuits, with a rated short-time withstand current |
| DC-1 | Non Inductive or slightly inductive loads, resistance furnaces, heaters |
| DC-3 | Shunt-motors, starting, plugging(1), inching(2), dynamic breaking of motors |
| DC-5 | Series-motors, starting, plugging(1), inching(2), dynamic breaking of motors |
| DC-6 | Switching of incandescent lamps |
| DC-12 | Control of resistive loads and solid state loads with opto-coupler isolation |
| DC-13 | Control of D.C. Direct current Direct current is the unidirectional flow of electric charge. Direct current is produced by such sources as batteries, thermocouples, solar cells, and commutator-type electric machines of the dynamo type. Direct current may flow in a conductor such as a wire, but can also flow through... electromagnetics |
| DC-14 | Control of D.C. electromagnetic loads having economy resistors in the circuit |
| DC-20 | Connecting and disconnecting under no-load conditions |
| DC-21 | Switching of resistive loads, including moderate overloads |
| DC-22 | Switching of mixed resistive and inductive loads, including moderate overloads (i.e. shunt motors) |
| DC-23 | Switching of highly inductive loads (i.e. series motors) |