CN88103459A

CN88103459A - The electronic protecting instrument of AC load

Info

Publication number: CN88103459A
Application number: CN88103459.2A
Authority: CN
Inventors: 丁春生
Original assignee: WANRONG COUNTY WATER CONVERVANCY ADMINISTRATION
Current assignee: WANRONG COUNTY WATER CONVERVANCY ADMINISTRATION
Priority date: 1988-06-06
Filing date: 1988-06-06
Publication date: 1988-11-30
Also published as: CN1007107B

Abstract

The electronic protecting instrument of AC load; belong to the electronic instrument class; phase shortage when it can protect electricity consumption; the phase failure; superpressure; under-voltage; the voltage between phases loss of equilibrium; load insulation against ground situation; overcurrent; short circuit; overheated; broken string; working condition with load group various devices even; the fault of environmental aspect; and can before starting, load carry out fault detect earlier to power supply and load top; can also be to the memory of breaking down; show; report to the police and outage shutdown in a second; the protection instrument also is provided with the time control of loaded work piece; clock; start-up control; program control and group control circuit; can protect many payload security work simultaneously, be applicable to the safeguard protection of various loads or using electricity system.

Description

The electronic protecting instrument of AC load of the present invention is a kind of electronic instrument, relates to the electronic instrument field.

To the protection with electric loading, the prior art situation in this field is at present: with the protection power failure is example, has Chinese patent CN85200321 number and is entitled as " multi-function overload switch for 3-phase power supply ", announces on April 30th, 1986.The described on-load switch of this patent can shield when the phase shortage of power supply, under-voltage, overcurrent and the disconnected four kinds of faults of fuse occur.Be example again with the motor protector, domestic existing commercial goods is as motor open phase protection instrument etc.These motor protectors mostly have only the minority defencive function, and what have can protect the phase failure, phase shortage, and what have can protect overcurrent, overheated, and what have has only single defencive function, combine to be characterized in: the few and imperfection of defencive function; The control circuit of outage of breaking down opens that control is slow, and what have reaches 20 minutes unexpectedly and just can open control, for the time fault lead to a disaster; Each defencive function circuit is simple, and the automation level is lower, to sensitivity, accuracy, the poor reliability of fault discriminating.Based on above-mentioned situation, these instruments can not be dealt with the complex situations of multiple faults, and safing safety factor is less.External situation is equally: though the product of motor protector is a lot; but defencive function is mostly less or single; machine examination rope as calculated; the technical literature of seeing has: No. 4291355, U.S. Pat " program control overload circuit "; this patent is described to be the automatic program control protective circuit of when overload motor overheating fault; its defencive function is single, but the defencive function circuit has adopted programming Control, and the automation level is higher.Russian Patent SU951540 number " electric motor protective device " is the protective device about motor overload, phase outage in addition.To also have the SU930484 patent be about motor overload, open circuit, the protective device of short circuit, overheating fault.The all less and imperfection of the defencive function of above-mentioned document, their functional circuit design simultaneously is also inequality with the present invention.Be example with the various loads of alternating current again; protectiveness research at present; only aspect the local of the load of some special purposes or main especially load or some; carry out specific aim research and protection; as military, underground, under water, hydraulic engineering, nuclear facility, traffic communications centre etc. adopt protective measure and device, majority has used computer control system.Yet both at home and abroad the emergency protection of very common, miscellaneous using electricity system of forming with electric loading or electricity consumption load is also carried out extensive studies far away, let alone mature technique scheme and products thereof occurred.

The electronic protecting instrument that the purpose of this invention is to provide various, perfect, sensitive, accurate, the reliable AC load of a kind of defencive function than automation.

Set forth technology contents of the present invention in conjunction with Figure of description.Fig. 1 is the electronic protecting instrument circuit block diagram of AC load of the present invention, each phase phase shortage of 1. power supplys, the phase failure, voltage between phases loss of equilibrium fault monitoring circuit among the figure; 2. each phase superpressure of power supply, under-voltage fault monitoring circuit; 3. the working condition fault monitoring circuit that connects device with load group; 4. the environmental aspect fault monitoring circuit that connects device with load group; 5. each phase overcurrent of load, short trouble observation circuit; 6. insulation status fault monitoring circuit between each phase-ground of load; 7. each phase disconnection fault observation circuit of load; 8. each phase overheating fault observation circuit of load; 9. the time control circuit of loaded work piece; 10. the circuit that clocks of loaded work piece; 11. the indicating circuit of loaded work piece; The control circuit that load was resumed work automatically when 12. fault was eliminated voluntarily; 13. load starts or compensation start-up control circuit; 14. the sequence circuit of multicircuit work; 15. protect the group control circuit of many loads; 16. the memory circuit of multicircuit band; 17. the demonstration of multicircuit band, the sound or warning circuit; 18. the switch of multicircuit band and brake control circuit; Be subjected to the control relation of group control circuit 19. represent first load; Be subjected to the group control circuit control relation 20. represent second load; 21. the expression group control circuit is to the control relation of more loads.Fig. 2 .a, b, c close the electronic protecting instrument non-limiting examples one that AC load of the present invention is shown.1 circuit theory sketch.Fig. 2 describes in detail when explanation embodiment.

The electronic protecting instrument of the AC load of a kind of combination and improvement invention; include each phase phase shortage of electronic circuit power supply of defencive function and other function; disconnected phase; voltage between phases loss of equilibrium fault monitoring circuit 1; each phase superpressure of power supply; under-voltage fault monitoring circuit 2; connect device working condition fault monitoring circuit 3 with load group; connect device context situation fault monitoring circuit 4 with load group; each phase overcurrent of load; short trouble observation circuit 5; insulation status fault monitoring circuit 6 between each phase-ground of load; each phase disconnection fault observation circuit 7 of load; each phase overheating fault observation circuit 8 of load; the time control circuit 9 of loaded work piece; the circuit 10 that clocks of loaded work piece; the indicating circuit 11 of loaded work piece; the control circuit 12 that load was resumed work automatically when fault was eliminated voluntarily; load starts or compensation starts control circuit 13, and the sequence circuit 14 of multicircuit work is protected many loads Group control circuit 15, the memory circuit 16 of multicircuit band, the demonstration of multicircuit band, the sound or warning circuit 17, the various components and parts of the switch of multicircuit band and brake control circuit 18 and power circuit and assembling circuit, indication, the sound, show, trip, switch, braking, sampling, sensing, input and the various parts of output, connector and their assembly, group connects lead, circuit board, apparatus frame and shell, the group of above-mentioned each circuit connect controlled all shown in Figure 1. Before load starts, under sequence circuit 14 controls of group control circuit 15 and control work thereof, each phase phase shortage of power supply, disconnected phase, voltage between phases loss of equilibrium fault monitoring circuit 1, each phase superpressure of power supply, under-voltage fault monitoring circuit 2(comprises the demonstration that respectively carries, the sound or warning circuit 17, switch and brake control circuit 18) work alone separately, insulation status fault monitoring circuit 6 between each phase-ground of meanwhile load, each phase disconnection fault observation circuit 7 of load, load starts or compensation starts control circuit 13, each phase overcurrent of load, short trouble observation circuit 5(comprises the memory circuit 16 that respectively carries, show, the sound or warning circuit 17, switch and brake control circuit 18), delayed time one by one by sequence circuit 14 controls works alone, insulation status fault monitoring circuit 6 between each phase-ground of load wherein, each phase disconnection fault observation circuit 7 of load, load startup or compensation startup control circuit 13 are finished under time-delay respectively and are worked alone; After load starts, under group control circuit 15 controls, each phase phase shortage of power supply, disconnected phase, voltage between phases loss of equilibrium fault monitoring circuit 1, each phase superpressure of power supply, under-voltage fault monitoring circuit 2, connect device working condition fault monitoring circuit 3 with load group, connect device context situation fault monitoring circuit 4 with load group, each phase overcurrent of load, short trouble observation circuit 5, each phase overheating fault observation circuit 8 of load, loaded work piece the time Control circuit 9(comprises memory circuit 16, demonstration, the sound or warning circuit 17, switch and the brake control circuit 18 that respectively carries), the circuit 10 that clocks of loaded work piece, the indicating circuit 11 of loaded work piece works alone separately; Before or after the load startup, each fault of all appearance is passed through the importation of fault monitoring circuit separately and is imported monitored, fault to needs memories is remembered, display alarm and starting switch and brake control circuit action shutdown,, report to the police also starting switch and brake control circuit action shutdown shown to non-memory fault, when non-memory fault is eliminated voluntarily, the control circuit 12 that switch and brake control circuit 18 instruction loads are resumed work automatically sends signal, and group control circuit 15 and sequence circuit 14 control loads are resumed work; Time control circuit 9 sends signal when the time comes according to the start and stop instruction of load time control work makes switch and brake control circuit 18 control loads start or stop and do demonstration, sound reaction.

At protecting the different of load and needing; the electronic protecting instrument of AC load of the present invention must comprise outside the aforesaid function electronic circuit 1,5,12～14,16～18 as shown in Figure 1, can select also to comprise that remaining is a plurality of arbitrarily in the aforesaid function electronic circuit 1～18 as shown in Figure 1.

Insulation status between above-mentioned each phase phase shortage of power supply, the phase failure, voltage between phases loss of equilibrium, superpressure, under-voltage, each phase overcurrent of load, short circuit in this protection instrument, broken string, overheated, each phase-ground of load, working condition, each fault monitoring circuit of environmental aspect of connecting device with load group are formed or are formed than amplifying circuit by letter sample circuit, current ratio separately by signal sampling circuit, voltage contrasting amplified circuit separately.Described each signal sampling circuit includes sample of signal, sampled signal processing, sampled signal output, sample of signal can be adopted the whole bag of tricks, at first Qu Yang signal source can be various, as electricity, magnetic, light, heat, space-time situation etc., secondly should adopt different sampling methods to different signal sources.All sampling methods all can adopt known technology to go to realize.By multiple sampling method fault-signal all is transformed to the signal of telecommunication and just reaches the sampling purpose, so must remove to design corresponding sample circuit and take a sample according to the difference content of taking a sample.It is suitably selected that the sampling codomain of each signal also should be looked concrete condition, can be suitably selected in low pressure, high pressure or superhigh pressure scope as voltage sampling, and current sampling can be suitably selected in little electric current, big electric current or especially big current range.Sampling rate also should suitably be selected, as 1: 2,1: 5,1: 10 or the like.Sampled signal is handled the alternative and adjustable sex change of the numerical value comprise sampled signal, waveform, frequency, amplitude, phase place, such as rectification, filtering, stepping, the contents such as mutual conversion of sampling and all kinds of energy signals again, must go to realize by design function corresponding circuit.Sampled signal output can be adopted several different methods, as capacitance-resistance output, and level output or the like, the numerical value of output signal, waveform, frequency, amplitude, phase place all should be able to modulation and selections.Described each voltage contrasting amplified circuit include the input of tested and comparison signal, voltage ratio, voltage amplification, segment signal output.Tested and comparison signal can adopt side by side or merge input mode, and signal output also can be adopted the output of diode or Resistor-Capacitor Unit.Input should be able to be selected and be regulated with numerical value, waveform, frequency, amplitude, the phase place of output signal.Use can be distinguished or mix to voltage ratio with amplification two circuit.Voltage ratio can select for use the circuit that can finish the voltage comparing function to realize, as being the main voltage comparator circuit that constitutes with switching device, also available integrated circuit block constitutes the circuit with voltage comparing function.The voltage comparator circuit of various structures must have two inputs and an output at least.Described each current ratio than amplifying circuit include the input of tested and comparison signal, current ratio, electric current amplifies, segment signal output.Every three fault monitoring circuits of phase shortage, the phase failure, voltage between phases loss of equilibrium that are provided with of going up mutually of power supply can be unified shared.The superpressure of each phase of power supply, under-voltage fault monitoring circuit degeneracy respectively are that a superpressure that a superpressure fault monitoring circuit becomes with a under-voltage fault monitoring circuit and degeneracy can be arranged on the arbitrary of power supply separately with a under-voltage fault monitoring circuit and goes up mutually.Each signal sampling circuit of each phase overcurrent of load, short trouble observation circuit 5 can adopt common end export structure in parallel.Every two fault monitoring circuits of overcurrent, short circuit that are provided with of going up mutually of load can be unified shared.The above-mentioned circuit design of respectively unifying shared or degeneracy, emphasis point is the selection of sample circuit and improvement, particularly in the codomain scope of sampled signal and the selection of sampling rate are wanted accurately with suitable, with sensitivity, accuracy and the reliability of guaranteeing to monitor each fault.The time control circuit of described loaded work piece is the time control circuit of timer control, and it is opened with two the time control circuit in time control pass by time control and forms.The time control circuit comprise timer, timer, switching circuit, control signal output.Timer can be selected various clock and watch or digital timer for use.Timer can be selected timing switch or timing clock etc. for use, and timer should be able to be selected regularly arbitrary time span in 24 hours.The circuit when circuit that clocks of described loaded work piece is accumulative total.The circuit that clocks comprises the tired timer and the circuit part of triping.Tired timer is the timer with accumulation clocking capability, and as memory type digital timer, digital progression timer etc., the tired timer of optional suitable timing quantitative range uses it.The indicating circuit of described loaded work piece comprises indicating circuit, trip circuit part.Indicating circuit can be that the master constitutes by indicating devices such as indicator light, indication gauge outfit, indicating instruments.The control circuit 12 that load was resumed work automatically when described non-memory fault was eliminated voluntarily is gating circuit, switching circuit, trip circuit or their mixed circuit of forming.This circuit comprises signal input, control circuit, segment signal output.Described load start-up control circuit comprises trip circuit, control signal output.Load compensation start-up control circuit comprises bleeder circuit, trip circuit, control signal output.Described sequence circuit 14 is made up of multistage delay control circuit or is made up of prime delay control circuit, multistage delay control circuit.The prime delay control circuit comprises time-delay regulation and control, delay circuit, time-delay control output.Multistage delay control circuit is multistage stable state delay control circuit, multistage stable state delay control circuit time-delay control input, steady-state circuit, trip circuit, the time-delay control outputs of including at different levels.The time-delay regulation and control can be adopted accomplished in many ways, realize delaying time such as the electric current of using signal, voltage, waveform, frequency, phase place etc. and regulate and control, and can select as required time of delay.It is main formation that delay circuit can be selected suitable steady-state circuit that delay function is arranged or integrated circuit block for use.Described group control circuit 15 by lattice network or/and sequence circuit form.Lattice network can adopt dot matrix list network configuration or the multiple network configuration of primary-secondary type.Dot matrix list lattice network is made up of some point control circuits, array control circuit.Point control circuit, array control circuit include multiterminal input and output, control circuit, trip circuit part separately.The multiple network configuration of primary-secondary type is made up of plurality of sub lattice network, overall network circuit.Each sub-network circuit is formed by the circuit of some dot matrix list network configurations.The overall network circuit comprises multiterminal input and output, control circuit, trip circuit part.The sequence circuit structure of forming group control circuit is identical with above-mentioned sequence circuit, no longer repeats.The memory circuit 16 of described multicircuit band includes signal input and output, memory circuit part separately.Memory circuit can be main formation with the components and parts that memory function is arranged, as with controllable silicon being main formation.The display circuit of multicircuit band includes signal input, display circuit part separately.Display circuit can be main formation with display unit.Display unit is indicator light, luminous component such as light-emitting diode, charactron etc.The sound of multicircuit band or warning circuit include signal input, sound circuit, sound parts separately.Sound circuit comprises oscillating circuit, voicefrequency circuit part.Sound parts can adopt electric bell, loud speaker etc.But the sound of each circuit band or warning circuit degeneracy are to be subjected to each circuit Control work and a shared sound or warning circuit respectively.The switch of multicircuit band and brake control circuit 18 include signal input, control circuit, trip circuit, switching circuit, trip circuit, brake control circuit, braking circuit, brake component part separately.Each above-mentioned control circuit is formed by gating circuit, switching circuit, trip circuit or their hybrid circuit separately.Gating circuit can be with being mainly to constitute with door, not gate or door and their assembly.Switching circuit can be main formation with switching device.Above-mentioned all trip circuits are main formation by trip parts and assembly thereof separately.The parts of triping are relay and assemblies thereof of various model specifications.Brake control circuit and braking circuit are used for the brake component work that control load and group thereof connect device operation, speed change, stop etc.Brake component comprises damper brake, speed changer, clutch, brake etc.But the switch of multicircuit band and brake control circuit degeneracy are to be subjected to each circuit Control work and a shared switch and brake control circuit respectively.The above-mentioned all available known technology decision design of each function electronic circuit 1～18.The circuit elements device that uses in the protection instrument comprises various resistance, electric capacity, inductance and various semiconductor device and integrated circuit block.The switch that uses comprises switches such as the low pressure, high pressure of all size model.The sampled part that uses comprises various signal sampling components, as the transformer of sampling usefulness, auto-transformer, current transformer, sample resistance, electric capacity etc.The sensing element that uses comprises parts such as various smooth sensings, hot sensing, magnetic sensing, power sensing, odor sensing.Input comprises that with output block various cables, various special-purpose input and output are first-class.The connector that uses comprises the connector of the jack plug socket of all size model.Circuit board can be piecemeal and decker.Tool housing can be box, cabinet type, hanging, desk-top and console mode, also can be equipped with to move wheel etc.

The electronic protecting instrument advantage of AC load of the present invention is: one, defencive function and other diverse in function to load is perfect, and instrument has 26 kinds of electric functions, is provided with dozens of function electronic circuit; Use when two, having 11 kinds of functional circuits and to start before load starts, before starting, load just can a series of fault projects of power supply and load be detected in advance, eliminate the hidden danger fault that has led to before load starts, accomplish to prevent trouble before it happens, guarantee Electrical Safety; Control circuit that load is resumed work automatically when three, being provided with sequence circuit, memory circuit, fault and eliminating voluntarily etc., automaticity is higher; Four, be provided with group control circuit, can protect many loads and many using electricity systems that load is formed simultaneously; Five, be provided with the safety of various devices in electricity consumption that the working condition, the environmental aspect fault monitoring circuit that connect device with load group make this instrument can protect many loads simultaneously and connect with their groups; Six, each fault monitoring circuit monitoring function of this protection instrument is accurate, reliable, highly sensitive; Seven, the ON-OFF control circuit of this protection instrument opens control outage rapidly, also is provided with brake control circuit, but in outage brake application stoping also.Though to comprise electronic circuit many for this protection instrument in addition, the entire circuit structure makes every effort to oversimplify, and uses element few, and cost is low, and volume is little, and is in light weight, is a kind of popular product that uses that is fit to popularize.

Protection instrument of the present invention according to described technical scheme, has been assembled several non-limiting examples samples, and is good through trial effect.

The protection instrument non-limiting examples of AC load of the present invention is as follows:

Example one, 1. a, b, the c of former reason Fig. 2 of protection instrument circuit of the AC load of this embodiment close and illustrate.Fig. 2 is a circuit pre-ferred embodiment shown in Figure 1.Adopt accompanying drawing 1,2 and embodiment one, the 1. explanation that combines below.

Example one, 1. be one and be used for three phase mains, phase voltage 380V, two motors 177 and 185(and see Fig. 2) be the electronic protecting instrument of the alternating current machine of load.It is water pump that same load-group of motors connects device, their working condition fault monitoring circuit is a pump capacity fault monitoring circuit 3, the environmental aspect fault monitoring circuit is that water tower level (or well water level) fault monitoring circuit 4, two circuit are respectively specializing of circuit 3 shown in Figure 1 and 4.The power circuit of each circuit working of protection instrument of this example is 146～148 to handle the back power supply by transformation, rectification, filtering, voltage stabilizing among Fig. 2.32 output positive voltages (as+12V), 33 output negative voltages (as-6V).

Structure is formed.Fig. 1 with composition structure shown in Figure 2 is: every phase shortage mutually, the phase failure, the unification of voltage between phases loss of equilibrium fault monitoring circuit are shared, circuit 1 is respectively established one mutually, 142～144 sample circuits wherein, adopt the transformer sampling after rectification, filtering, to export by 22～24 respectively, 36,42,48 threes are main three voltage comparator circuits that are mutually related that constitute, and 53 amplify.To be a superpressure arbitraryly go up (going up mutually as c) mutually with a under-voltage fault monitoring circuit is arranged on three-phase for each phase superpressure of power supply, under-voltage fault monitoring circuit 2 degeneracys, wherein 145 is sample circuit, structure and 142 roughly the same, 25 are output, 57 is the main superpressure voltage comparator circuit that constitutes, and 62 amplify, and 58 is the main under-voltage voltage comparator circuit that constitutes, 63 amplify, and 57 and 58 are IC sheet operational amplifier.Pump capacity fault monitoring circuit 3,28 measuring junctions wherein, external pump capacity monitoring sampled part, it places the pumping line suitable position, takes a sample with the resistance form.IC sheet 74 is the main voltage comparator circuit that constitutes.76 amplify, water tower level (or well water level) fault monitoring circuit 4,26,27 measuring junctions wherein, external water tower level (or well water level) monitoring sampled part, it places water tower (or well) suitable position, take a sample with the resistance form, 175-1 is the normally open contact of 175 relay assemblies, and 69 is the main voltage contrasting amplified circuit that constitutes.The unification of motor 177 every phase overcurrents, short trouble observation circuit is shared, and three-phase is established three, wherein 168,169,170 is respectively and is located at current transformer that each goes up sampling mutually.After 171 rectifications, filtering and the end of allying the communists by 124,166-1 is defeated by measured signal, obtains comparison signal from 125, IC sheet 126 is the main voltage comparator circuit that constitutes, 166-1 is 166 normally open contact.Insulation status fault monitoring circuit 6 between motor 177 each phase-ground, wherein IC sheet 133 is the main voltage comparator circuit that constitutes, and 154 is sequence-controlled contacts, and an end that leans on its connection motor 177 three-way bag is to 133 input measured signals, and 135 amplify.Motor 177 each phase disconnection fault observation circuit 7, wherein 177 the tested end of the three-way bag of motor is shown, 138 and 140,139 and 141 form two voltages respectively from comparison circuit, and 164a, 164b do the measured signal input respectively, and 164a, b, c are sequence-controlled contacts.Motor 177 each phase overheating fault observation circuit 8, wherein 127 is the sampling detector of temperature-sensitive element, place motor 177 line bags nearby appropriate location do the temperature overheating sampling, IC sheet 130 is the main voltage comparator circuit that constitutes.The time control circuit of motor 177 work is (because of the interlock of two motor combination, also time-controlled motor 185), wherein 91 open, stop the contact for clock control, 92,92a is the double-pole two-throw switch, be out to change switch with stall, controllable silicon 88 is the main control circuit when opening that constitutes, the 30th, open contact, 93 is main constitute control circuit when closing down, the 31st, coila.The circuit 10 that clocks of motor 177 work, wherein 176 is tired timers, the 175 parts normal open contacts of triping are controlled.The indicating circuit 11 of motor 177 work, the work of its indication 68,184 switch, 177 start-stops, power circuit, group control circuit, sequence circuit is not.For the sake of simplicity, not shown in Figure 2.Motor 177(also had 185 when non-memory fault was eliminated voluntarily) control circuit 12 of resuming work automatically, it contain be located at 86 separate in the buckle assembly for its normal open contact and with 86 synchronous controlled actions.The compensation start-up control circuit 13 of motor 177 comprises 172～174 and sequence-controlled contacts 165, wherein 173,174,165 is respectively switch or separates buckle assembly, and 172 is three auto-transformers.The sequence circuit 14 of motor 177.Wherein IC sheet 151 is the main prime delay control circuit that constitutes.149, the 150th, the time-delay regulation and control, 155,160 is the main one-level time-delay control that constitutes steady-state circuit, 154 are the programme controlled buckle assembly of separating of this grade, the secondary time-delay illustrates by 164, three grades of time-delays illustrate by 165, the level Four time-delay illustrates by 166, and the Pyatyi time-delay illustrates by 167, and they all have same circuit structure with the one-level time-delay.In fact the sequence circuit 14 of motor 177 includes only prime and level Four delay circuit, the monitoring (from the prime delay working) of the power failure phase shortage of program controlled motor 177, the phase failure, superpressure, under-voltage, voltage between phases loss of equilibrium, insulation fault monitoring (finishing between the one-level time delay), disconnection fault monitoring (finishing between the secondary time delay), compensation start-up control (finishing between three grades of time delays), over current fault monitoring (from the level Four work of having delayed time).The sequence circuit of motor 185 is formed with the sequence circuit mixing of motor 177 in this example.This is the cause because of

motor

177 and 185 linkage works, is a kind of special circumstances.The sequence circuit of motor 185 comprises prime time-delay 151～Pyatyi time-delay 167, the power supply phase shortage of their program controlled motors 185, the phase failure, superpressure, under-voltage, voltage between phases loss of equilibrium malfunction monitoring (from the prime delay working), the empty time-delay of one-level, insulation fault monitoring (finishing between the secondary time delay), disconnection fault monitoring (finishing between three grades of time delays), the empty time-delay of level Four, control starts and over current fault monitoring (the Pyatyi delay working rises).Group control circuit 15 also mixes composition with the sequence circuit of motor 177 and motor 185, and it comprises compositions such as prime time-delay 151, Pyatyi time-delay 154,164～167 and time-delay control output step by step (being again subordinate's time-delay input) 159.Group control circuit 15 in this example is mixed by lattice network and sequence circuit and forms, and mixes with the sequence circuit of two motors 177,185 again, is a kind of special circumstances, all because of can the link cause of joint control of two motors.When many loads of protection can not link, the circuit 14 of circuit 15 and each load was looked the discrete or mixing of concrete condition.The memory circuit 16 of each circuit band of motor 177 comprises controllable silicon 88,93,111,114,117, the 120 main memory circuit that constitutes of respectively doing for oneself.The display circuit of motor 177 each circuit band comprises the display circuit that

indicator light

54,59,64,70,77,89,94,112,115,118,121 constitutes.Sound circuit comprises that IC sheet 98,104, triode 107 are main sound circuit, cycling circuit and the amplifying circuit that constitutes, and 165 are the program control contact, make motor 177 and start the sound.The warning circuit of each circuit band by each circuit by diode respectively Control work unify sharedly, it comprises that 98,107,101 loud speakers are the sound parts of the sound and warning circuit.The switch of each circuit band of motor 177 and brake control circuit 18 by each circuit by diode respectively Control work unify shared, comprise that 81,85,86 is the main main control circuit that constitutes and by trip circuits such as 173,174,175,183 of relay assembly 86 controls, switching circuit, trip circuit, brake control circuit, braking circuit and brake component.173～175,183 etc. for triping and switch module, is provided with in brake control circuit, this example of braking circuit.About each functional circuit of motor 185, what have is shown in Figure 2, as the sequence circuit of group control circuit and 185, and start-up circuit 183, overcurrent and circuit sampling circuit 178～182 etc.Because of it and 177 motors with power supply joint control interlock again, 185 power supply phase shortage, the phase failure, superpressure, under-voltage, voltage between phases loss of equilibrium fault monitoring circuit, in generation, can not omitted to the greatest extent by motor 177 monitorings and is provided with in addition, the time control circuit, the circuit that clocks can not omit yet pump capacity, shared needn't the establishing in addition of water tower level (or well water level) malfunction monitoring are set in addition.Remaining circuit is not shown in Figure 2, but the congenerous circuit of these circuit structures and motor 177 entirely together.

Motor

177 and 185 each functional circuit and the required various components and parts of power circuit; indication, the sound, show, trip, switch, sampling, sensing, input and output block, connector and their assembly, according to the circuit requirement of Fig. 1 and Fig. 2 be assembled on the circuit board, on apparatus frame and the shell and connect lead, connector etc. with group and link electronic protecting instrument for complete alternating current machine.

The course of work, the protection instrument course of work branch of this example open control work and fault and two processes occur and narrate.

Start, referring at first closed master switch 184 of Fig. 2 and manual switch 68, power circuit 146～148 is started working, power supply is confessed by 32,33, this moment, the main control circuit 81,85 of switch and brake control circuit was started working, because 79 fault-free signals input 81 is in cut-off state, 85 are in conducting state, 86 work, i.e. 86 operating states that when fault-free, often are in connection.86 make group control circuit 15 and sequence circuit 14 energized 32,34 start working, so far each circuit is all powered, can begin to work alone, when circuit 15 and 14 work, at first control work is opened in prime time-delay 151, circuit 1 and 2 is started working between this grade time delay, power supply before the electric motor starting is had or not phase shortage, the phase failure, superpressure, under-voltage, voltage between phases loss of equilibrium fault is monitored in advance, after electric motor starting, each sample circuit 142～144 work, by 22～24 respectively to

voltage comparator circuit

36,42, the mutual comparison signal of 48 inputs, but 36,42,48 are in cut-off state when fault-free is imported, 145 pass through 25 to

voltage comparator circuit

57 and 58 input comparison signals simultaneously, when fault-free, this signal level is lower than comparative level to 57 makes 57 output negative levels, and 62 end, be higher than comparative level to 58 and make 58 output positive levels, 63 end.After the prime time-delay is finished, through 159 input time delay control signals, make 155,160 work of one-level delay circuit, between this time delay, a phase line bag of motor 177 in 154 work and the connection circuit 6, insulation status malfunction monitoring between finishing motor 177 each phase-ground under the Program time delay control.133 work during this, but because of the fault-free signal level is higher than comparative level, 133 output positive levels, 135 not conductings.After the one-level time-delay is finished, open control secondary delay working step by step, in 164 whens work, connected 164a, b, c makes in the motor 177 triple line bag places in circuit 7 and finish between this time delay motor 177 each phase disconnection faults monitoring, also can not finish the monitoring of motor 185 insulation status.When the fault-free signal 138 and 140,139 and 141 two from comparison circuit work and no-output.The secondary time-delay is finished and is opened three grades of delay workings of control in turn, between this time delay, connect 173,174 during 165 work, make the work of compensation start-up circuit, 172 work, motor 177 is finished compensation and is started, 165 also control sound circuit 104 work, cadence signal makes 107 conductings by 106,98 work, and 101 send motor 177 starts the sound.Between this time delay, also can finish the open phase fault monitoring of motor 185.When three grades of time-delays were finished, 165 quit work, make 172～174 and sound circuit 104,107,98,101 all quit work.During the level Four delay working, 166 work, 166 controls, 175 work between this time delay, make 177 to receive normal electrical operation off the net by 175 switches, make tired timer 176 connection work, so circuit 10 is started working, 166 quit work when the level Four time-delay was finished, and 166～1 normally open contacts are connected, and circuit 5 is started working, overcurrent or short trouble can be taken a sample by 168～170, handle the back and ally the communists and hold through 171 by 124,166～1 input voltage comparison circuits 126, though 126 work when fault-free, the output negative level, 111 not conductings, the sequence circuit work of motor 177 finishes to this moment, and control work is then opened in the Pyatyi time-delay, 167 work, motor 185 between this time delay 167 control under, connect 183,183 switches and make motor 185 connect network operation, when the Pyatyi time-delay is finished, 167 quit work, and 167～1 normally open contacts can be connected the overcurrent of motor 185, the work of short trouble observation circuit.178～180 can make current sampling.167～1 and 185 overcurrent, short trouble observation circuit are not shown in Figure 2.To under group control circuit control, work at each circuit 1～5,8～12,16～18 behind two electric motor startings.74 of circuit 3 has delay function, and it is between time delay in the electric motor starting process, and 76 are in cut-off state.Behind the electric motor starting, 74 delay time just finishes, be in operating state, but output positive level during 28 end fault-free, 76 end, and water tower level (or well water level) circuit 4 is owing to the normally open contact 175～1 that is connected to 175, and 175～1 often contact before electric motor starting, 26～27 can not input signal, and 69 by not conducting.After motor 177 starts, 175 work, 175～1 disconnect 26～27 ability input fault signals, and when the fault-free signal, 69 still end.Circuit 8 could be worked after motor 177 starts.Be lower than 129 comparative level by 127 input fault-free signal levels, though fault-free negative level, 114 not conductings are only exported in 130 work.When circuit 9 instructs in no time control.91 disconnect, and 92 groups of time switchs are to starting or stoping, the time control circuit all be in and treat operating state.Each indicating circuit of circuit 11 is along with the circuit start that is instructed to and work and work successively.88,93,111,114,117,120 memoryless signals of each memory circuit of circuit 16 are in when importing treats operating state.54,59,64,70,77,89,94,112,115,118,121 no shows signal of each display circuit of same circuit 17 are imported and are in and treat operating state.The warning circuit 98 of circuit 17 ends the work for the treatment of because of 107 when the fault-free signal.The governor circuit 81 and 85 of circuit 18 is just started working after the power supply power supply, and during no signal input under normal circumstances, 81 often are in cut-off state, and 85 often are in conducting state, and 86 often are in the connection operating state.Circuit 12 will or stop with 86 work as a normal open contact of 86 assemblies.That has so far narrated each functional circuit of this example protection instrument opens the control course of work.This process character narrate is very long, but actual process only can be finished within 2～3 minutes from close a floodgate electric motor starting work and the controlled work of each circuit.

Each circuit working process when narration was broken down below fault occurred, situation appears in the fault of at first narrating circuit 1, from the back prime time-delay of powering, circuit 1 is just started working, suppose and carve the arbitrary phase of three phase mains (as the A phase) at a time, appoint two-phase or three-phase phase shortage or the phase failure or voltage between phases loss of equilibrium fault to occur, this fault is always sampled, establishing A earlier breaks down mutually, 142 samplings are after 22 transport to 39, behind 39 step-down 0.7V, 36 base potential is raise relatively, 36 by ending the change conducting, and then make 53 conductings, show so 54 make fault, fault-signal is through 52,29,109,108 make 107 conductings, make 98 work, 101 send warning, fault-signal is through 52,79 make 81 conductings, make 85 to become by conducting and to end, 86 quit work, before appearing at motor and do not start as this fault, no matter 86 group control circuit 15 and sequence circuit 14 their program control work are all quit work immediately to that one-level, when pending fault is eliminated, just can restart start-up course, appear at after motor 177 starts as fault, 86 quit work, and group control circuit 15 is quit work make 175,183 grades quit work, 177,185 outages are shut down, circuit 10 also stops to clock, and after fault is got rid of, could carry out a series of start-up courses again; When if this fault is eliminated voluntarily, 36 end because of base potential relatively descends to being become by conducting.53 no longer export fault-signal, 54 no longer fault demonstrations, 101 fault alarms no longer, 81 end again, 85 conductings again, and 86 resume work, 86 power supplies of connecting circuit 15 and 14 of circuit 12, under circuit 15 and 14 controls, each circuit repeats a series of start-up courses automatically, and

motor

177 and 185 is resumed work automatically.Occur on two-phase in office or the three-phase with fault, fault will be taken a sample by 142～144, by 36,42,48 relatively also conductings, 54 make fault shows that 101 make fault alarm, and 85 end, 86 quit work, and then make 177,185 to quit work, just can restart after fault is got rid of, or fault is eliminated the back 86 control motor 177,183 of resuming work voluntarily and is resumed work automatically.

For the fault that circuit 2 occurs, suppose that carving the arbitrary phase of power supply three-phase (as the A phase), a two-phase or three-phase at a time superpressure or under-voltage fault occur.Suppose that superpressure or under-voltage fault appear in A mutually, fault is by 145 samplings, be defeated by 57 or 58 respectively through 25, if this fault-signal of superpressure fault makes 57 fault level be higher than comparative level, 57 output positive levels make 62 conductings, make 59 to do the demonstration of superpressure fault, if under-voltage fault, this fault level is lower than 58 comparative level, makes 58 output negative levels, makes 63 conductings, 64 make under-voltage fault shows, the superpressure fault is through 65, and under-voltage fault makes 107 conductings, 98 work through 66 and 29,101 make fault alarm, make 81 conductings through 79,85 end, and 86 quit work.If fault appears at certain moment in the start-up course, 86 quit work circuit 15 and 14, and from then on start-up course stops.If when occurring in machine operation, 86 quit work circuit 15,10 and 175,183 etc.,

motor

177 and 185 shutdown of also cutting off the power supply.Can restart after fixing a breakdown, motor is resumed work.When this fault is eliminated voluntarily, the output of 145 fault-free signals, superpressure 57 and under-voltage 58 comparison circuit fault-free signals are imported also fault-free signal output, 59 or 64 fault-free show that 101 do not make fault alarm, and 81 conductings change ends, 85 by becoming conducting, 86 work, control circuit 15,14 work are resumed work until motor.

The pump capacity fault appears about circuit 3; suppose that the some time behind the pump working carves existing pump capacity fault, pump capacity diminishes or becomes not to be had by the 28 sampling ends sampling inputs 74 that connect, and makes 74 output fault negative levels; 76 conductings; 77 make fault shows, makes 101 to report to the police through 29, and fault makes 81 conductings; 85 end; 86 quit work, and circuit 15,10 is quit work, and the motor outage is shut down.When fault is got rid of, can restart machine operation, or when the flow fault was eliminated voluntarily, circuit 12 was resumed work circuit 15 and 14 control motors.

Ifs circuit 4 water tower levels (or well water level) break down; as full certain moment that occurs in motor and water pump work to peak level (or the well water level is lower than a certain water level) of water level; 26～27 sampling fault-signals make 69 base stages reach the conducting current potential; 69 work; 70 make fault shows; 101 make fault alarm; 81 conductings; 85 end; 86 quit work, so circuit 15,10 quits work, the motor outage is shut down; when pending fault is got rid of or fault when eliminating voluntarily, could resume work by starter motor.

Ifs circuit 5 carves existing motor 177 overcurrents or short trouble at a time, supposes that this fault appears on motor one phase (A phase) or a two-phase or the three-phase.See that earlier fault appears on the phase (as the A phase); fault is defeated by 126 by 168 instrument transformers samplings through 171,124,166～1, because the fault level is higher than comparative level, makes 126 output positive levels; make memory circuit 111 do the fault memory by 110; make fault by 112 and show, make 101 to report to the police through 113, make 81 conductings; 85 end; 86 quit work, and circuit 15,10 is quit work, and the motor outage is shut down.Because this fault is provided with memory circuit, so fault is once conducting controllable silicon 111 just always by memory, demonstration, warning, shutdown, after fault is got rid of, just can restart machine operation.For appointing two-phase or three-phase overcurrent, short trouble to occur, must be by the sampling of 168～170 current transformers, be defeated by 126 through 171,124, all the other processes such as A phase fault are analyzed, and no longer repeat.

Failure condition for insulation status between circuit 6 motors 177 each phase-ground.During sequence circuit one-level delay working, 154 work, finish motor 177 insulation fault monitorings, supposing has insulation fault to exist, and during 154 connection circuit 6, fault-signal imports 133 from motor 177 through 154, because the fault level is lower than comparative level, 133 output fault negative levels make 135 conductings, and 117 do the fault memory, and 118 make fault shows, fault makes 101 to report to the police through 119, also make 81 conductings, 85 end, and 86 quit work, circuit 15,14 is quit work, start-up course is ended therefrom, when fault is got rid of, just can restart machine operation.As between the one-level time delay, circuit 6 monitoring naked faults, circuit 15,14 will be controlled subordinate's time-delay and open control work, and start-up course also will go on as usual.

During sequence circuit is in the secondary delay working, circuit 7 will be finished motor 177 disconnection fault monitorings, if any disconnection fault, fault is taken a sample from 177 motors, by 164 and 164a, b, c connect circuit 7, no matter be motor 177-phase, two-phase or three-phase broken string, fault-signal improves 138 or 139 current potentials, make their conductings and open control 120 and do fault memory, 121 make fault shows that 101 report to the police, and 86 quit work, circuit 15,14 is quit work, and start-up course is ended thus.When fault is got rid of, just can restart.As between two utmost point time delays, no disconnection fault exists, and will normally carry out start-up course after the secondary time-delay.

The a certain moment after machine operation, overheating fault appears in motor 177, this fault is set at the heat sensor 127 of motor appropriate location and surveys and sampling, be defeated by 130, make 130 output fault positive levels, make 114 to do the fault memory, 115 make fault shows, make 101 to report to the police by 116, make 86 to quit work, and then circuit 15,10 and motor are quit work.When fault is got rid of, just can restart machine operation.

The time control working condition of 9 pairs of motors 177 of analysis circuit again.When motor is in stopped status; drive motor due to certain time control constantly; stir timing switch contact 91 regularly, simultaneously 92 groups also dialled to 30a to 30(92a), to start constantly; 91 connect control circuit when opening; the time control start-up command is through 92; 30 make 88 conducting work, and 89 open demonstration do time control, and starting-up signal makes 81 to end through 87; 85 conductings; 86 work make circuit 15; 14 control motors carry out working after a series of start-up courses, think the time control shutdown constantly as certain that move at motor; stir 91 regularly; with 92 groups to 31, arrive to shut down constantly, 91 connect time controls closes circuit; halt instruction is through 92; 31 make 93 conducting work; 94 do to shut down demonstration, and stopping signal also makes 81 to become conductings, and 85 end; 86 quit work; and then make circuit 15; 10 quit work, and motor is shut down; be noted that: open and close down 2 o'clock control circuits and adopt memory circuit to realize that 88 or 93 once conducting work; disconnect 91 timing points, still do not influence and open or close down the time control circuit working.

When various fault occurring; the working condition of circuit 10～12,14～18 is narrated, and the governor circuit 86 of circuit 18 will be controlled each switching circuit, trip circuit, trip circuit, brake control circuit and braking circuit and close down or breakdown action in the closing down and open of various faults occurring.The work of circuit 13 is narrated in startup.

Above-mentioned analyzed this example one, 1. in whole circuit structures of a load one motor 177 form and the course of work; also can as above equally analyze narration for motor 185, this example protection instrument designs at the motor 177,185 of combination interlock and the protection of water pump.

Example one, the 2. protection instrument described in example one, 1; its protection load is not a motor; but electric heating, electroluminescence, electroacoustic picture, electrochemistry, electric refrigeration, electrical transmission, electric control, electrical measurement, electricity metering, electricity medical treatment, ionization, electric arc, many loads of holding aspects such as power transformation, electromagnetism conversion; or above-mentioned various load mixes the electricity consumption load system of forming, and the electrical functions circuit of protecting these loads its structure as shown in Figure 1 is analogous to example one, 1 circuit 1～18.The variation different with example one, 1 is not to be motor but protection instrument that above-mentioned various AC load uses.

Example one, 3. as the electronic protecting instrument of example one, 1 or 2 described AC loads; difference along with load; the device that connects with load group is not a water pump; but various lathes, hoisting machinery, electric locomotive, various power consumption equipment, instrument, device, the circuit 3 of these protection instrument or circuit 4 will connect the different related circuits that look concrete condition design congenerous of device according to group.This example protection instrument changes the electronic protecting instrument that is to have the AC load that the various groups of various loads that connect device use.

Example one, 4. as the protection instrument of example one .1 or 2 or 3 described AC loads, be with above-mentioned routine difference:

A, can be used on the protection instrument of single-phase, three-phase or multi-phase AC power.

B, can be used for the protection instrument that the AC load of different rated voltages, electric current and power uses.

The protection instrument of example two, the arbitrary routine AC load described in example one, the electric function circuit that it comprises is deleted the protection instrument that is assembled into behind power supply superpressure, load short circuits, overheating fault observation circuit and the time control operating circuit.

The protection instrument of example three, the AC load described in example two, the electric function circuit that it comprises is deleted the protection instrument that is assembled into behind power supply phase shortage, the phase failure, load broken string, the insulation status fault monitoring circuit.

Example four, as the protection instrument of example three described AC loads, the electric function circuit that it comprises is deleted line under-voltage, is connected the protection instrument that is assembled into behind the circuit that clocks of device working condition, environmental aspect fault monitoring circuit and loaded work piece with load group.

Claims

1; a kind of protection instrument of AC load; include each phase phase shortage of power supply; the phase failure; voltage between phases loss of equilibrium fault monitoring circuit 1; each phase superpressure of power supply; under-voltage fault monitoring circuit 2; connect device working condition fault monitoring circuit 3 with load group; connect device context situation fault monitoring circuit 4 with load group; each phase overcurrent of load; short trouble observation circuit 5; insulation status fault monitoring circuit 6 between each phase-ground of load; each phase disconnection fault observation circuit 7 of load; each phase overheating fault observation circuit 8 of load; the time control circuit 9 of loaded work piece; the circuit 10 that clocks of loaded work piece; the indicating circuit 11 of loaded work piece; the control circuit 12 that load was resumed work automatically when fault was eliminated voluntarily; load starts or compensation start control circuit 13; the sequence circuit 14 of multicircuit work; the group control circuit 15 of many loads of protection; the memory circuit 16 of multicircuit band; the demonstration of multicircuit band; the sound or warning circuit 17; the various components and parts of the switch of multicircuit band and brake control circuit 18 and power circuit and assembling circuit; indication; the sound; show; trip; switch; braking; sampling; sensing; input and the various parts of output; connector and their assembly; group connects lead; circuit board; apparatus frame and shell is characterized in that:

A, before load starts, under sequence circuit 14 controls of group control circuit 15 and Control work thereof, each phase phase shortage of power supply, the phase failure, voltage between phases loss of equilibrium fault monitoring circuit 1, each phase superpressure of power supply, under-voltage fault monitoring circuit 2 (comprises the demonstration that respectively carries, the sound or warning circuit 17, switch and brake control circuit 18) work alone separately, insulation status fault monitoring circuit 6 between each phase-ground of load meanwhile, each phase disconnection fault observation circuit 7 of load, load starts or compensation start-up control circuit 13, each phase overcurrent of load, short trouble observation circuit 5 (comprises the memory circuit 16 that respectively carries, show, the sound or warning circuit 17, switch and brake control circuit 18), delayed time one by one by sequence circuit 14 controls works alone, insulation status fault monitoring circuit 6 between each phase-ground of load wherein, each phase disconnection fault observation circuit 7 of load, load startup or compensation start-up control circuit 13 are finished under time-delay respectively and are worked alone;

B, after load starts, under group control circuit 15 controls, each phase phase shortage of power supply, the phase failure, voltage between phases loss of equilibrium fault monitoring circuit 1, each phase superpressure of power supply, under-voltage fault monitoring circuit 2, connect device working condition fault monitoring circuit 3 with load group, connect device context situation fault monitoring circuit 4 with load group, each phase overcurrent of load, short trouble observation circuit 5, each phase overheating fault observation circuit 8 of load, the time control circuit 9 of loaded work piece (comprises the memory circuit 16 that respectively carries, show, the sound or warning circuit 17, switch and brake control circuit 18), the circuit 10 that clocks of loaded work piece, the indicating circuit 11 of loaded work piece works alone separately;

C, before or after load starts, each fault of all appearance is passed through the importation of fault monitoring circuit separately and is imported monitored, the fault of need memory is remembered, is shown, reported to the police and starting switch and brake control circuit action shutdown, non-memory fault is shown, reports to the police and starting switch and brake control circuit action shutdown, when non-memory fault is eliminated voluntarily, the control circuit 12 that switch and brake control circuit 18 instruction loads are resumed work automatically sends signal, and group control circuit 15 and sequence circuit 14 control loads are resumed work;

D, the time control circuit 9 send when the time comes according to the start and stop of load time control work instruction that signal makes switch and brake control circuit 18 control loads start or stop and make demonstration, the sound reacts.

2, the protection instrument of AC load as claimed in claim 1; it is characterized in that: the protection instrument must comprise outside the function electronic circuit 1,5,12～14,16～18 described in claim 1, also can select comprise that remaining is a plurality of arbitrarily in the function electronic circuit 1～18 according to the different needs of protection load.

3, the protection instrument of AC load as claimed in claim 1 or 2 is characterized in that:

A, each phase phase shortage of described power supply, the phase failure, voltage between phases loss of equilibrium fault monitoring circuit 1, each phase superpressure of power supply, under-voltage fault monitoring circuit 2, connect device working condition fault monitoring circuit 3 with load group, connect device context situation fault monitoring circuit 4 with load group, each phase overcurrent of load, short trouble observation circuit 5, insulation status fault monitoring circuit 6 between each phase-ground of load, each phase disconnection fault observation circuit 7 of load, each phase overheating fault observation circuit 8 of load is separately by signal sampling circuit, voltage contrasting amplified circuit or separately by signal sampling circuit, current ratio is formed than amplifying circuit;

B, every three fault monitoring circuits of phase shortage, the phase failure, voltage between phases loss of equilibrium that are provided with of going up mutually of described power supply can be unified shared;

C, each phase superpressure of described power supply, under-voltage fault monitoring circuit respectively degeneracy to be superpressure becoming with a under-voltage fault monitoring circuit and degeneracy of a superpressure fault monitoring circuit all can be arranged on each mutually arbitrary of power supply separately with a under-voltage fault monitoring circuit goes up mutually;

D, every two fault monitoring circuits of overcurrent, short circuit that are provided with of going up mutually of described load can be unified shared;

The time control circuit 9 of e, described loaded work piece is the time control circuit of timer control, and this circuit is opened with two the time control circuit in time control pass by time control and formed;

The circuit when circuit that clocks of f, described loaded work piece is accumulative total;

G, described sequence circuit 14 are made up of prime delay control circuit and multistage delay control circuit;

H, described group control circuit 15 by lattice network or/and sequence circuit form;

I, the control circuit 12 that load was resumed work automatically when described fault was eliminated voluntarily are circuit that gating circuit, switching circuit, trip circuit or their mixing are formed;

But the sound in the demonstration of j, described multicircuit band, the sound or the warning circuit 17 or warning circuit degeneracy are to be subjected to each circuit Control work and a shared sound or warning circuit respectively;

But the switch of k, described multicircuit band and brake control circuit 18 degeneracys are to be subjected to each circuit Control work and a public switch and brake control circuit respectively.

4, the protection instrument of AC load as claimed in claim 3 is characterized in that;

Each signal sampling circuit of a, each phase overcurrent of described load, short trouble observation circuit 5 adopts and the end export structure of allying the communists;

The multistage delay control circuit of b, described sequence circuit 14 is multistage stable state delay control circuits.