Dual power automatic transfer switch selection model
Dual power automatic transfer switch ( English abbreviation is ATSE ) in today's work has been playing an increasingly important role, especially in some places of electricity. Typically, double power automatic switch by a backup power supply, to ensure the normal power after a problem, you can normally use, has the very good reliability and should be acute, so popular. But some customers in the purchase of existing error, only pay attention to its rated current and series, and decides to double power supply automatic to correct selection of double power supply automatic switch of the first condition, it is necessary to make clear the following parameters: rated voltage rated current of Ue, Ie, frequency, phase, rated conditional short-circuit current, conversion conditions, use categories, conversion time.
Conversion time
Dual power automatic transfer switch every transformation is a power-off process, of the system have some effect. From the standard, there are five kinds of transformation time concept, there are two kinds of transformation concept of time most value: a minimum off time (by the switch body mechanism, decision ) is a total conversion time ( i.e. ontology conversion time controller + delay time ). Different load and power status, have different requirements, need to pay attention to. In the confirmation of the conversion time, attention should be paid to have two time state transitions, one is from the common power supply to standby power, one is from the standby power is returned to the common power.
1 from the common supply to standby power, need to consider different load allowed outage time, see below:
Note: the dual power automatic transfer switch minimum off time by the switch body inherent conversion speed, usually has three kinds of structures: ( to 100A below current grade ATSE for example ) the fastest STS conversion time can be less than 5ms; excitation drive PC ATSE, minimum conversion time can be less than 0.1s; the ATSE ( motor drive CB level and using load switch as the body 's PC dual power automatic transfer switch ), the conversion time is larger than 1.5s in general. Because of the different switch off time is different, therefore, the requirements of power off time is less than 1.5s occasions, should be particularly noted changeover time requirements.
2 from the standby power is restored to the normal power (i.e., reset ), not because of standby power supply fault. Don't usually want to commonly used to power a restored immediately conversion ( this point is often neglected ), and need in the common power returned to normal after a certain period of time ( IEC62091 fixed fire pump controller is proposed to reset the time in between 5min30min adjustable ), ATSE before switching to the normal power ( time delay reset aims to ensure a common power supply is normal, to avoid because the common power short time again failed, leading to frequent switching or frequent starting of diesel engine, so, the return time to delay ).
3 for some complex systems ( such as ATSE number and double power supply automatic switch over three stage tandem system ), between the upper and lower levels, disordered conversion or conversion can cause system instability, therefore, need to double power automatic transfer switching times" ordered", is generally recommended to lower levels than the switching time delay 1s. Note: the excitation driving dual power automatic transfer switch has two work stations and three stations two structures, two stations during the delay, switch is to maintain the original state of connection, three station delay, switch that can be kept in its original state, also can stay in the middle position ( two disconnected simultaneously ). Motor driven ATSE ( CB level and load switch composed of PC class ATSE ), in the automatic conversion, is a direct conversion to another power, this structure delay process, contact is stuck in the same position. So, if the delay process needs to contact remains at the middle position ( e.g. high inductance load ), can only choose the excitation driving the three stations. In order to meet the requirements of the design of delay, ( or document ) can be prescribed delay switching time has the scene adjustable function, adjust the time in between 030min. 3.4 categories were used : the use of categories reflect the dual power automatic transfer switch can be in what current conditions for reliable conversion, which is currently the most overlooked, but also on the market the problem with most potential danger. The use of categories from the switch body ( contact material, contact pressure, the separation speed, arc, contact distance and other materials and structural elements ) decision. Using the category of national standards are clearly defined
Rated working voltage, current, frequency and phase number
These parameters only that the dual power automatic transfer switch to meet as a" conductor" is the most basic requirement, it must be able to meet the voltage, current, frequency and phase number requirements, general electrical engineers are familiar with. Note: the voltage, frequency, number of phases are usually made of double power supply automatic switch location of the corresponding parameters. Rated current in accordance with the" IEC 62091 fixed fire pump controller" standard for fire pump, ATSE, shall not be less than the motor rated current rated current of 115%, from a security perspective, the proposed ATSE rated current uniform load current ( 125% new regulations also suggest 125% ).
Conversion condition
We need a ATSE purpose, is the need for" specific " under the conditions of ATSE automatically enables reliable conversion. The" specific requirement" is ATSE conversion conditions, or convert the premise, is the choice of ATSE primary consideration factors.
1 if the common power without fault, dual power automatic transfer switch can not be converted.
This is one of many users ( even manufacturer ) are ignored. Dual power supply automatic changeover switch controller must be able to identify the various voltage instantaneous fluctuation, including a power failure of short-term pressure loss. For example, substation low-voltage bus-tie switch belongs to the normal power supply interruption, should not be the parent link switching power determines the power failure, need to be able to determine the" normal" blackout. The controller must pass the EMC test, not to external electromagnetic interference misoperation. Note: the conversion condition by the controller functions to decide, on power failure judgment means ( including fault type identification ) is the controller's core technology, general product information is not introduced, see manufacturer research and development level and industry experience, designers need to understand product judgment mechanism.
2 in the power failure conditions necessary to convert.
But due to a power failure of many kinds ( 10 ), therefore, need to clear the fault must convert. Because of the complexity of user demand, general supplier provide a variety of features of the controller, therefore, when designing must be based on the load on the quality of the power requirement clearly indicate the conversion condition, otherwise, because of the double power automatic transfer switch market supply disruptions and the owners of the ATSE do not know much about, leading to the final use of the product often is only able to completely lose electric a condition could change, and other power failure ( including phase, over and under voltage ) do not convert, lose with meaning. Note: because of the dual power automatic transfer switch function is still not standardized, product model design only, does not guarantee that users understand the selected model conversion conditions, leading to the actual selection of products and design requirements vary, suggestions for the design of state conversion conditions. For example, an arbitrary phase phase, overvoltage, undervoltage, frequency deviation, harmonics, wherein, any one phase fault is necessary to convert the is the minimum requirement. End of the controller, can even comprehensive examination power quality, automatic access power quality a higher power.
The above information by the country electric switch factory for you, www.jiandq.com