Automatic Transfer Switch
Automatic switching device intended to monitor power-source availability and transfer a load between sources according to defined control logic.
An automatic transfer switch (ATS) is intended to monitor one or more electrical power sources and automatically transfer a load to an available source when specified conditions are met.
The device may monitor voltage, frequency, phase presence, phase sequence, and other source parameters. Depending on the design, the transfer controller may be integrated into the switching device or implemented as a separate external unit.
ATS logic may provide source priority, automatic retransfer after restoration of the normal source, adjustable source-failure and return delays, a center-OFF delay, generator start and stop control, test modes, and load shedding.
The switching section may use different transition types between sources together with mechanical or electrical interlocking. Some versions include a motor operator, local HMI, display, digital inputs and outputs, event log, real-time clock, and communication interfaces.
Advanced models may support remote configuration and diagnostics, integrated measurement of electrical parameters, and data exchange with automation systems.
Selection criteria include the number and type of sources, TSE class, transfer arrangement and time, monitored network parameters, timing adjustment ranges, generator control logic, pole arrangement, motor-operator characteristics, control and communication interfaces, rated electrical values, and declared compliance with applicable standards.
This subcategory includes automatic transfer switches (ATS), automatic standby transfer equipment with integrated or external controllers, motorized transfer devices with automatic operation, source monitoring, generator functions, HMI, communication, and diagnostics.
Automatic Transfer Switch
General9
Commercial or technical designation of a manufacturer's product family sharing a common design and compatible characteristics.
Range of tasks and systems for which the manufacturer recommends the component.
Primary function of the device and its intended use as defined by its design and the manufacturer's documentation.
Permissible installation location of the product: indoors, outdoors, in a technical area, or as part of equipment.
Environmental conditions under which installation and operation of the product are permitted.
Permissible spatial orientation of the component during installation and operation.
Manufacturer-defined designation of the product frame size or construction size.
Actual electrical pole configuration of the product, including the number and function of switched poles.
Set of switching functions for which the product is designed or declared suitable.
Dimensions8
External horizontal dimension of the product between its outermost lateral points.
External vertical dimension of the product from its lowest to its highest point.
External distance between the foremost and rearmost surfaces of the product.
Horizontal dimension of the mounting cutout or opening required to install the product in a prepared surface or recess.
Vertical dimension of the mounting cutout or opening required to install the product in a prepared surface or recess.
Depth of the enclosure portion installed within a wall or mounting recess.
Distance by which the front part of the installed product projects beyond the wall surface.
Depth of the mounting cutout or recess intended to accommodate the recessed part of the product.
Capacity and Layout4
Number of defined functional positions of the product's main switching mechanism.
Functional sequence or designation of the switching positions provided by the product.
Number of mechanically or electrically linked switching units forming the product.
Number of electrical power sources between which the device can transfer the connected load.
Materials and Finish10
Primary material from which the product is manufactured.
Grade, alloy, class, or technical designation of the product's primary material.
Primary visually perceived colour of the product's external surface.
Designation of the product's primary surface colour according to the RAL colour system.
Type of final surface finish of the product determining its appearance and service properties.
Character of the surface microrelief and visual structure after manufacturing or finishing.
Technological surface treatment applied to modify its protective, mechanical, or decorative properties.
Type of protective, functional, or decorative coating applied to the surface.
Material or chemical basis of the coating applied to the surface of the product or one of its parts.
Thickness of the coating layer applied to the surface of the product or one of its parts.
Mounting and Installation25
Installation arrangement permitted by the product design, such as wall-mounted, flush-mounted, floor-mounted, or another specified mounting type.
Method used to mechanically secure the product to a support, surface, or load-bearing structure.
Type of surface or supporting base to which the product may be fixed.
Number of holes provided in the product for mechanical fixing.
Diameter of the hole provided for a fixing element used when mounting the product.
Distance between the centres of mounting holes in the horizontal direction.
Distance between the centres of mounting holes in the vertical direction.
Size designation of the screw, bolt, or other threaded fastener used for mounting the product.
Designation of the thread provided in the product's mounting holes or fixing elements.
Tightening torque recommended or permitted for fasteners during product installation.
Indicates whether the required fasteners are included with the product.
Primary material of screws, bolts, nuts, rivets, and other product fasteners.
Indicates whether the design provides for mounting equipment on a DIN rail.
Indicates whether equipment may be mounted directly to the mounting surface without an intermediate DIN rail.
Indicates whether the intended installation of the product can be carried out without tools.
Horizontal dimension of the mounting pattern between the outermost fixing points of the product.
Vertical dimension of the mounting pattern between the outermost fixing points of the product.
Geometric shape of the hole intended for mechanical fixing of the product.
Minimum free space required above the product for installation, cooling, or servicing.
Minimum free space required below the product for installation, cooling, or servicing.
Minimum free space required to the left of the product for installation or servicing.
Minimum free space required to the right of the product for installation or servicing.
Minimum free space required in front of the product for installation and normal operation.
Minimum free space required behind the product for installation and normal operation.
Minimum free space in front of the product required for safe access during servicing.
Electrical Parameters62
Type of electrical current for which the product's main supply circuit is intended.
Voltage value assigned to the product by the manufacturer for specified application conditions and characteristics.
Rated RMS value of alternating voltage assigned to the product by the manufacturer.
Rated direct voltage assigned to the product by the manufacturer.
Operating-circuit voltage with reference to which the product's performance characteristics are specified.
Maximum voltage at which continuous operation of the product is permitted under the conditions declared by the manufacturer.
Minimum voltage at which the manufacturer guarantees the intended operating mode of the product.
AC frequency assigned to the product for normal operating conditions.
Lower limit of the electrical network or signal frequency at which product operation is permitted.
Upper limit of the electrical network or signal frequency at which product operation is permitted.
Number of phases of the electrical system for which the product is designed to be connected or used.
Configuration of live and neutral conductors of the electrical system supported by the product.
Pole-count configurations for which the product is intended to be used or connected.
Current assigned to the product by the manufacturer for the declared operating and thermal conditions.
Highest rated current permitted for the relevant version or configuration of the product.
Conventional free-air thermal current Ith that the device can carry under specified steady-state conditions in free air.
Conventional enclosed thermal current Ithe that the device can carry under specified steady-state conditions inside the intended enclosure.
Current that the product can carry continuously under the manufacturer's declared conditions without exceeding permissible temperature rise.
Voltage with reference to which the product's insulation clearances and dielectric properties are specified.
Peak value of an impulse voltage of specified waveform that the product insulation must withstand without breakdown.
Test voltage applied to verify the dielectric strength of the product insulation.
Category characterizing the expected level of impulse overvoltages at the product's point of use.
Degree of pollution of the surrounding microenvironment considered when selecting insulation distances and product characteristics.
RMS value of short-time withstand current Icw that the product can withstand for the declared duration without unacceptable damage.
Duration for which the product must withstand the declared short-time current.
Peak current value Ipk that the product can withstand under the declared short-circuit conditions.
Prospective short-circuit current that the product can withstand when the specified external protective device is used.
Rated short-circuit making capacity Icm characterizing the ability of the device to make a circuit under specified short-circuit conditions.
Manufacturer-declared permissible short-circuit current value for the product or assembly under specified conditions.
Indicates whether an external short-circuit protective device is required for the declared operation of the product.
Indicates whether an additional upstream protective device is required to achieve the declared product characteristics.
Maximum thermal power loss that the product can dissipate under specified conditions.
Thermal power loss of the product or current-carrying system at rated current.
Ambient temperature to which the manufacturer's declared electrical or thermal characteristic applies.
Manufacturer-declared utilization category defining the load characteristics and switching conditions according to the applicable standard.
Declared number of mechanical operating cycles that the product can perform without electrical switching load.
Declared number of electrical load-switching cycles under the conditions specified by the manufacturer.
Maximum nominal conductor cross-section permitted at the product's incoming connection.
Maximum nominal conductor cross-section permitted at the product's outgoing connection.
Minimum conductor cross-section permitted for connection to the incoming terminal of the main power circuit.
Minimum conductor cross-section permitted for connection to the outgoing terminal of the main power circuit.
Maximum nominal cross-section of the neutral conductor permitted by the relevant product connection.
Minimum neutral conductor cross-section permitted for connection to the corresponding product terminal.
Conductor materials for which the specified terminals and connection methods are designed.
Conductor connection methods supported by the specified terminals or connection elements.
Conductor construction classes permitted by the product's electrical connection system.
Maximum number of main-power-circuit conductors that may be connected simultaneously to one terminal.
Tightening torque specified by the manufacturer for a screw or bolted terminal connection.
Ratio of the permissible current-carrying capacity of the neutral conductor or busbar to the corresponding phase current capacity.
Indicates whether the neutral conductor can be disconnected for servicing or testing.
Indicates whether switching of the neutral conductor together with the live conductors is provided.
Electrical and switching arrangement of the product's neutral pole.
Sequence of making and breaking the neutral pole relative to the phase poles.
Indicates whether the sequence or timing of neutral-pole switching relative to the phase poles is adjustable.
Maximum nominal cross-section of the PE protective conductor permitted by the relevant product connection.
Minimum PE protective conductor cross-section permitted for the specified protective connection of the product.
Rated external auxiliary supply voltage required for the product's active functions.
Type of current and source used for the product's auxiliary supply.
Voltage applied to the control circuit to perform the product's intended functions.
Type of current used in the product's control circuit.
Frequency of the alternating voltage or signal in the product's control circuit.
Minimum permissible insulation resistance between the specified electrically separated parts.
Protection and Safety15
Degree of enclosure protection against access to hazardous parts and ingress of solid objects and water, designated by the IP code.
IP degree of protection provided by the accessible front side of the product after its intended installation.
Class of enclosure resistance to external mechanical impacts designated by the IK code.
Indicates whether the declared ingress protection of the enclosure has been verified by certification or testing.
Method or level of protection of the user against direct contact with hazardous live parts.
Indicates whether the design prevents finger access to hazardous live parts in the intended condition.
Indicates whether the design provides protection against accidental contact with hazardous live parts.
Indicates whether insulating or mechanical protective shrouds are included with the product.
Indicates whether live parts are covered by protective elements in the intended product state.
Indicates whether the design supports door interlocking depending on the state of installed equipment or a mechanism.
Indicates whether the product can be locked with a padlock.
Diameter of the hole or opening intended for the shackle of a padlock.
Indicates whether the material and coating are designed to withstand ultraviolet radiation.
Indicates whether the product materials retain their declared properties when exposed to the specified oils.
Groups of chemicals or environments whose effects the product can withstand under the declared conditions.
Environmental Conditions26
Minimum ambient temperature at which normal operation of the product is permitted.
Maximum ambient temperature at which normal operation of the product is permitted.
Minimum ambient temperature permitted during storage of the product while not in operation.
Maximum ambient temperature permitted during storage of the product while not in operation.
Minimum ambient temperature at which the manufacturer permits installation of the product.
Maximum ambient temperature at which the manufacturer permits installation of the product.
Maximum relative air humidity permitted for the declared operating or test condition.
Indicates whether the product's resistance to vibration has been verified under the declared conditions.
Indicates whether the product's resistance to short-duration mechanical shocks has been verified.
Maximum permissible average ambient temperature over a consecutive 24-hour period.
Minimum ambient temperature permitted during transportation of the product.
Maximum ambient temperature permitted during transportation of the product.
Indicates whether permissible electrical or thermal loading must be reduced as temperature changes.
Temperature above which the permissible product load must be reduced.
Indicates whether the manufacturer has published the relationship between permissible product load and temperature.
Minimum relative air humidity permitted for the declared operating or test condition.
Temperature at which the corresponding relative humidity value is specified or standardized.
Indicates whether the permissible humidity value applies only to non-condensing conditions.
Maximum altitude above sea level at which the product may be installed without exceeding the declared conditions.
Indicates whether the permissible product load must be reduced as installation altitude increases.
Altitude above sea level above which the permissible product load must be reduced.
Indicates whether the manufacturer provides a table or curve for derating the permissible load when operating above the reference altitude.
Standard or method used for climatic, mechanical, or combined testing of the product.
Indicates whether the product's ability to maintain declared properties under seismic effects has been verified.
Classification designation of the product's seismic resistance according to the declared standard or method.
Standard or method according to which the product's seismic resistance has been verified.
Included Equipment15
Indicates whether a local control element such as a handle, lever, rotary element, or similar device is supplied with the product.
Indicates whether one or more auxiliary contacts are included in the standard product configuration.
Indicates whether an extension shaft for remote mechanical transmission of motion is supplied with the product.
Indicates whether an accessory pack is included in the product's standard equipment.
Indicates whether an installation hardware kit is included in the product's standard equipment.
Indicates whether documentation is included in the product's standard supply.
Indicates whether an installation manual is included with the product.
Indicates whether a wiring diagram is included with the product.
Number of normally open (NO) auxiliary contacts installed in or supplied with the product.
Number of normally closed (NC) auxiliary contacts installed in or supplied with the product.
Number of changeover auxiliary contacts installed in or supplied with the product.
Indicates whether an alarm signalling contact is included in the product's standard equipment.
Indicates whether the product is supplied assembled by the manufacturer.
Indicates whether internal electrical connections were completed by the manufacturer before delivery.
Indicates whether the manufacturer performed the specified factory checks or tests before delivery.
Special Features96
Indicates whether the switching device is declared suitable for providing an isolation function.
Indicates whether a positive mechanical relationship exists between the position indication and the actual position of the main contacts.
Indicates whether visible indication is provided to determine the position of the main switching contacts.
Type of mechanism that transmits the operating action to the main switching contacts of the product.
Type of physical local control element used to operate the product.
Indicates whether direct manual operation of the product's main switching function is supported.
Indicates whether the product can be fitted with a compatible motor operator as optional equipment.
Indicates whether the product supports installation or connection of specified auxiliary contacts.
Indicates whether the product is compatible with a mechanism that transmits motion from a control element mounted on a cabinet door.
Indicates whether the product is compatible with an extension shaft for remote mechanical transmission of operating motion.
Switching positions in which the product design permits mechanical locking with a padlock.
Maximum number of padlocks that may be fitted simultaneously to the provided locking mechanism.
Indicates whether the product is compatible with a shunt trip for electrically commanded opening.
Indicates whether the product is compatible with an undervoltage release.
Indicates whether an auxiliary contact for electrical signalling of the main switching mechanism position is supported.
Power-source arrangements or combinations for which the device is declared suitable for load-transfer operation.
Class of transfer switching equipment (TSE) according to the applicable IEC 60947-6-1 classification.
Method of electrically transferring a load from one source to another, defined by the opening and closing sequence of the switching paths.
Indicates whether electrical interlocking is supported to prevent impermissible simultaneous switching of related devices or sources.
Indicates whether the design permits mechanical interlocking of devices or moving parts.
Manufacturer-declared time required to transfer the load between power sources, excluding intentionally configured time delays unless otherwise specified.
Supported modes for determining priority between available power sources.
Indicates whether automatic retransfer of the load to the priority source is supported after the required source conditions are restored.
Indicates whether operator-initiated retransfer of the load to the priority source is supported.
Indicates whether transfer between sources is supported when specified phase-relationship conditions are satisfied.
Indicates whether an integrated controller performs source monitoring and automatic load-transfer logic.
Indicates whether an external controller is required to implement the specified source-transfer logic.
Indicates whether the controller can be powered directly from the monitored sources without a separate auxiliary power supply.
Electrical parameters and source conditions that the device can monitor when making transfer decisions.
Indicates whether the user can configure the parameters and conditions used for source monitoring.
Indicates whether one or more voltage-monitoring threshold values can be adjusted.
Indicates whether one or more frequency-monitoring threshold values can be adjusted.
Indicates whether the delay between detection of an unacceptable source condition and the subsequent transfer-system response can be adjusted.
Minimum available setting for the response delay to a failed or unacceptable power-source condition.
Maximum available setting for the response delay to a failed or unacceptable power-source condition.
Indicates whether the delay before retransferring the load to a restored source can be adjusted.
Minimum available setting for the delay before returning to a restored power source.
Maximum available setting for the delay before returning to a restored power source.
Indicates whether the intentional time delay in the intermediate OFF position between source switching operations can be adjusted.
Minimum available setting for the dwell time in the intermediate OFF position.
Maximum available setting for the dwell time in the intermediate OFF position.
Indicates whether the delay for transferring the load between power sources can be adjusted.
Minimum available setting for the load-transfer delay between sources.
Maximum available setting for the load-transfer delay between sources.
Indicates whether the delay before issuing a standby-generator start command can be adjusted.
Minimum available setting for the delay before issuing the generator start command.
Maximum available setting for the delay before issuing the generator start command.
Indicates whether the delay before issuing a generator stop command can be adjusted.
Minimum available setting for the delay before issuing the generator stop command.
Maximum available setting for the delay before issuing the generator stop command.
Indicates whether an output for issuing a generator start command is present or supported.
Indicates whether a function for inhibiting the generator start command is supported.
Indicates whether a generator test mode with transfer of the specified load to the tested source is supported.
Indicates whether a generator test mode without transferring the load to the tested source is supported.
Indicates whether shedding or limiting part of the load under specified power-system conditions is supported.
Indicates whether an external command that initiates load transfer between power sources is supported.
Indicates whether an external input signalling power-source availability or readiness is present or supported.
Indicates whether an external input for inhibiting automatic operation of the transfer system is supported.
Functional bypass arrangement provided by the design of the switching equipment.
Indicates whether the bypass includes interlocking that prevents impermissible combinations of switching positions.
Manufacturer-declared time required by the motor operator to perform the specified switching operation.
Indicates whether a local human-machine interface (HMI) is provided for monitoring, configuration, or control.
Indicates whether the product has an integrated local display.
Technology or construction type of the product's integrated display.
Indicates whether the integrated display has a backlight.
Number of integrated LEDs used to indicate product status or operating modes.
Indicates whether the product can store an internal event log.
Maximum number of event records that can be stored in the product's internal log.
Indicates whether an integrated real-time clock is provided for timekeeping, event time-stamping, or time-based functions.
Number of available digital inputs of the product.
Number of available digital outputs of the product.
Indicates whether user-configurable functions can be assigned to one or more digital inputs.
Indicates whether user-configurable functions can be assigned to one or more digital outputs.
Indicates whether the product supports digital data exchange with external devices or systems.
List of supported digital data communication protocols.
List of supported physical or logical digital communication interfaces.
Indicates whether an integrated web server or web interface is provided for access to product functions.
Indicates whether specified product settings can be read or changed remotely through a supported communication interface.
Indicates whether diagnostic information, status data, or fault information can be obtained remotely.
Indicates whether the product includes integrated electrical measurement functionality beyond basic source-condition monitoring.
Indicates whether the product can measure and provide electrical voltage values.
Indicates whether the product can measure and provide electrical current values.
Indicates whether the product can measure and provide electrical network frequency values.
Indicates whether measurement of active, reactive, or apparent electrical power is supported.
Indicates whether measurement or cumulative metering of electrical energy is supported.
Indicates whether measurement or analysis of harmonic components of electrical quantities is supported.
Indicates whether a discrete alarm signal can be generated through the provided signalling contact.
Indicates whether the product is structurally or interface-ready for connection to remote condition or parameter monitoring systems.
Indicates whether local manual override is provided with intended priority over automatic, programmed, or electrically commanded operation.
Physical position of the local control element on the product or relative to its enclosure.
Indicates whether the product's main operating function can be controlled by a remote command.
Indicates whether a touchscreen is provided for user input through the local HMI.
Indicates whether the product can perform its main operating function automatically without a direct operator command for each switching operation.
Indicates whether the HMI can be mounted separately from the main switching-device enclosure while retaining the intended interface functions.
Indicates whether an integrated motor operator is provided to mechanically operate the switching device.
Indicates whether the motor operator can be replaced as a separate component provided for by the product design.
Standards and Compliance23
Certification, market-approval, or conformity marks applicable to the product.
Primary normative document or standard according to which the manufacturer classifies or assesses the product.
Additional normative documents and standards declared by the manufacturer as applicable to the product.
Indicates whether an official declaration of conformity is available for the product.
Indicates whether a certificate relating to the declared certification or conformity of the product is available.
Indicates whether the CE marking is applied to the product where applicable.
Indicates whether the product has a declared UL Listed certification or recognition status.
Indicates whether the product has a declared UL Recognized certification or recognition status.
Indicates whether the product has a declared CSA certification or recognition status.
Indicates whether the product has a declared TÜV certification or recognition status.
Indicates whether the product has a declared VDE certification or recognition status.
Indicates the presence of an approval or certification for use of the product on railway rolling stock or in railway infrastructure.
Indicates whether product compliance with applicable RoHS restrictions on hazardous substances has been declared.
Indicates whether the manufacturer declares compliance of the product with applicable REACH Regulation requirements.
Additional manufacturer information concerning standards, certificates, declarations, and limitations of the declared compliance scope.
Indicates whether the manufacturer declares product compliance with IEC 60529.
Indicates whether the product has been tested according to applicable methods of the IEC 60068 series.
Indicates declared compliance of the product with the applicable general requirements of IEC 60947-1 for low-voltage switchgear and controlgear.
Indicates declared compliance of the product with the applicable IEC 60947-3 requirements for switches, disconnectors, switch-disconnectors, and fuse-combination units.
Indicates manufacturer-declared suitability of the product for use as service equipment where that classification is applicable.
Indicates declared compliance of the product with the applicable IEC 60947-6-1 requirements for transfer switching equipment (TSE).
Indicates declared compliance of the product with the applicable UL 1008 requirements for transfer switching equipment.
Indicates declared compliance of the product with the applicable CSA C22.2 No. 178.1 requirements for transfer switching equipment.
Logistics10
Mass of the product itself, excluding transport packaging, additional accessories, and external equipment.
Mass of the product together with its individual packaging and the accessories included in it.
External horizontal dimension of the product's individual package.
External vertical dimension of the product's individual package.
External depth dimension of the product's individual package.
Design type of the product's individual or transport packaging.
Number of individual products contained in one packaging unit at the specified level.
Country of origin of the goods declared for customs or commercial purposes.
Commodity code under the international Harmonized Commodity Description and Coding System.
Commodity code under the Combined Nomenclature of the European Union.