Commonly used electric equipment has a lot of, wait like breaker, contactor, relay, hot relay, switch, these are strong return, additionally still PLC waits, these equipment reach station room utility in pneumatics machine very extensive, can saying is requisite. Accordingly, to the breakdown of commonly used and electric equipment maintenance principle and method undertake control appropriately, special the work efficiency that is helpful for promoting pneumatics machine operation, dimension to keep staff and major are spent.

One, the decathlon principle that electric equipment maintains

1. Move a mouth to start work again first

To having the electric facility of breakdown, should not be eager to starting work, should enquire the around course that produces breakdown and breakdown phenomenon first. To rusty equipment, still answer to be familiar with circuit principle and structural characteristic first, abide by corresponding regulation. Means of the function that before disassembling, wants to be familiar with every electric component adequately, position, join and with all round the relation of other parts of an apparatus, below the circumstance that does not have assembly drawing, answer to disassemble at the same time, draw sketch at the same time, make number.

2. First exterior hind in-house

Should check equipment to have first without apparent rift, be short of caustic, understand its maintenance history, use fixed number of year, check to undertaking inside machine again next. Circumjacent breakdown element should queue up before tearing open, it is the ability after the breakdown inside machine to disassemble certainly, otherwise, disassemble blindly, the likelihood repairs facility worse more.

3. First machinery hind is electric

It is only after barrier of without reason of affirmatory and mechanical spare parts, have the examination of electric field again. When checking circuit breakdown, should use testing instrument to seek breakdown position, affirm without the contact after undesirable breakdown, again what specific aim ground examines circuit and machinery run a concern, lest miscarriage of justice.

4. The trends after Xian Jing condition

In equipment not when electrify, judge the stand or fall of electric equipment pushbutton, contactor, hot relay and fuse, decide thereby the place of breakdown. Electrify experiments, listen to its sound, measure breakdown of parameter, judgement, undertake maintaining finally. If be short of in electromotor when the photograph, if measure three phase voltage,the value cannot be worn when differentiate, should hear its voice, measure every opposite ground voltage alone, just can judge which one photograph to be short of caustic.

5. Maintain after cleanness first

Heavier to pollution electric equipment, nod to dot of its pushbutton, wiring, contact first undertake cleanness, check exterior control key to whether be out of order. A lot of breakdown are by smudgy reach electric conduction dirt piece causes, once clean breakdown often can eliminate.

6. First the equipment after power source

The proportion that the fault rate of power source part holds in whole breakdown equipment is very high, overhaul power source first so often can get twice the result with half the effort.

7. First general hind special

The trouble that causes because of assembling fittings quality or other equipment malfunction, take common trouble commonly 50% the left and right sides. The special breakdown of electric equipment is soft breakdown more, want to rely on experience and appearance to measure and be maintained.

8. First the interior after periphery

Do not be eager to changing first the electric component of attaint, when affirming peripheral equipment circuit is normal, consider to change again the electric component of attaint.

9. Communicate after dc first

When the overhaul, must check job of dc loop static state to nod first, communicate loop trends job to nod again.

10. Debug after breakdown first

2, examination method and operation practice

1. Direct way

Direct way is the exterior expression according to electric equipment breakdown, through looking, hear, listen wait for a method, the examination, method that judges breakdown.

(1) inspect step:

Investigate a case: To handlers and breakdown present staff enquires a circumstance, include stoppage exterior expression, roughly circumstance of the place, environment when malfunctioning. Whether to if have,stand by electric equipment without unusual gas, bright fire, heat source, have invade without caustic gas, have without slack, whether somebody has been repaired, repaired content is waited a moment.

Preliminary check-out: According to the circumstance of investigation, see concerned electric equipment exterior have nondestructive bad, have even the line without open circuit, become loose, insulation has without scorch, whether does the indicating device of helix fuse jump out, electric equipment has without dirty into water, oil, switch place is proper wait.

Test-drive: Pass preliminary check-out, affirm have can make trouble further expand and cause postaccident of person, equipment, but farther test-drive examination, should notice to have in test-drive wait for a phenomenon without serious flash over, off-odour, unusual sound, once discovery should jockey instantly, dump. Whether does the behavioral program that notes the temperature rise that checks electric equipment and electric equipment accord with the requirement that electric equipment principle pursues, discover breakdown place thereby.

(2) check a method:

Observation scintilla: The contact of electric equipment is in close, the meeting when switching circuit or lead thrum become loose produces scintilla, because this is OK according to scintilla have without, the phenomenon such as size will check electric equipment breakdown. For example, when the discovery between the lead that originallies closely normally and bolt has scintilla, explain thrum becomes loose or the contact is undesirable. The contact of electric equipment is in close, the flash over when switching circuit explains circuit is connected, not flash over explains circuit is illogical. The contactor that controls electromotor advocate when contact two-phase has scintilla, one photograph not to have scintilla, show the one posture contact that does not have scintilla is contacted undesirable or circuit of this one photograph opens circuit; It is normal that the scintilla of the two-phase in three-phase is compared big, it is normal to be not compared small, but preliminary judgement is short circuit of electromotor alternate with or ground connection; It is normal that three-phase scintilla is compared big, the likelihood is electromotor overload or mechanical part card live. In auxiliary circuit, after electrify of contactor coil circuit, armature is not sucked close, circuit open circuit or contactor machinery block should be distinguished to cause partly. Can start pushbutton by, if pushbutton often opens contact closed position to disconnect from time to tome slight scintilla, show circuit access, breakdown is in the mechanical part of contactor; If scintilla is not had between contact, showing circuit is open circuit.

Behavioral program: The behavioral program of electric equipment should accord with the requirement of electric manual and blueprint. The electric equipment start that goes up like some circuit is too premature, late or not movement, explain this circuit or electric equipment have trouble.

Additional, analyse of divide into equal parts of the sound that still can give out according to electric equipment, temperature, pressure, odour judges breakdown. Use intuitionistic method, not only can decide simple breakdown, still can narrow more complex breakdown to lesser limits.

2. Measure voltage way

Measuring voltage way is the power supply means according to electric equipment, the voltage value that measures each to nod and electric current are worth and compare with normal value. Specific can divide it is cent rank to measure law, section to measure law and dot to measure a way.

3. Measure resistor way

Can divide it is cent rank to measure law and section to measure a way. These two kinds of methods apply to the electric facility with distributinging larger space of switch, electric equipment.

4. Component of comparative, displacement, progressively open a way (or receive) law

(1) antitheses: Detect data and blueprint data and the normal parameter photograph that record at ordinary times judge breakdown quite. Do not have the electric equipment that records at ordinary times again to having a data, can compare with the photograph of in good condition electric equipment that is the same as model.

When the electric equipment component in circuit belongs to same control property or many component control same equipment jointly, can use other likeness or the component movement condition of same power source will judge breakdown.

(2) buy changes component way: When the breakdown reason of certain circuitry decides not easily or examination time grows too, but to assure the utilization rate of electric equipment, can change test of yuan of parts of an apparatus with same photograph good performance, in order to confirm breakdown whether from this electric equipment is caused. The attention answers when applying changeover component law to check, should dismantle original electric equipment after falling, want serious examination to whether had damaged, because element of itself of this electric equipment causes damage,be for certain only when, ability changes new electric equipment, lest change element newly,damage again.

(3) progressively open a way (or receive) law: Much spur track is shunt-wound and when controlling more complex circuit short circuit or ground connection, have apparent exterior show commonly, like fume, scintilla waits. When electromotor interior or the circuit short circuit that contain shield, ground connection, outside dividing fuse fusing, discover other and exterior phenomenon not easily. This kind of circumstance can adopt progressively open a way (or receive) law examination.

Law of progressively open a way: Encounter the short circuit that checks hard or ground connection trouble, can change afresh fuse-element, circuit of cross-linking of much spur track, all the way all the way progressively or key ground disconnects from inside circuit, next electrify experiments, be like fuse again and again fusing, breakdown is on this circuit that just disconnects. Divide this spur track a few paragraphs again next, chase paragraph of ground to receive circuit. The fuse when should receiving some paragraph of circuit fusing, breakdown is on this paragraph of circuit and component of some electric equipment. This kind of method is simple, but easy the electric equipment component with a not serious damage is complete burn down.

Receive a standard stage by stage: When circuit occurrence short circuit or ground connection breakdown, change new fuse progressively or key ground each spur track receive power source, experiment afresh. The fuse when should receiving some paragraph fusing, on this circuit that breakdown just is receiving and the electric equipment element that its contain.

5. Force to close law

When breakdown of electric equipment queueing up, through was not being found after visual check breakdown is nodded and at hand also undertakes metrical without proper appearance, club of predestined relationship of usable a special skill will concern relay, contactor, electro-magnet to wait to press forcibly with outside force, make its often open contact to close, all sorts of phenomena that observe electric equipment part or mechanical part appear next, if electromotor never turns to roll, relevant section never moves equipment to move normally etc.

6. Short receive a standard

The breakdown of equipment circuit or electric equipment roughly the electromagnetism of mistake of reduce short circuit, overload, open circuit, ground connection, wiring, electric equipment and mechanical part breakdown 6 kinds. All kind appear in breakdown more for open circuit breakdown. It includes lead open circuit, empty to connect, become loose, contact contacts fusing of solder of undesirable, empty, false solder, fuse to wait. Divide to this kind of breakdown outside be being checked with resistance standard, voltage law, still have a kind of more simple and reliable method, it is short receive a standard. The method is the wire that uses a good insulation, the short circuit of open circuit place that suspects place is received rise, be like short receive somewhere, circuit job returns to normal, explain the place opens circuit. Particular operation can be divided for local short receive law and accident to receive a standard.

Above checks a method a few kinds, want to learn to be used alive alive, abide by safety to operate regulations. The reentry after should proving a cause to yuan of parts of an apparatus that burns out continuously changes all right; Lead should consider when voltage is measured pressure fall; Do not violate principle of pilot of equipment electric equipment, the hand when test-drive must not leave mains switch, and insurance should be used wait for a quantity or be less than rated electric current slightly; Notice those who measure an instrument to block choice.