Check and find some common problems in electrical circuits in air compressors - industrial machines
1. Steps need to be taken while repairing power of compressors
When the production machine is broken, is it important to detect a broken circuit? In the electrical cabinet or at the instrument panel? Failue in electric motors in power stage or control circuits?
There are simple failures, the machine can normally operate after detecting and handling . With the correct judgment where the problem occurred will help electrician repair quickly and effortlessly.
Firstly, ask the operator what happened? The machine runs weak, works properly but not automatically or fumes out somewhere Carefully read the principle diagram and assembly diagram thinking about the above information to localize the broken area. 2. Initial inspection Initial inspection is a general test method that does not require any electrical measuring instrument. Do not disconnect the power, only open the suspeted "zone" , observe the lines, electric tools, the recovery buttons of the thermal relay to see if there are any abnormal signs such as wires is broken, slip or stick, the thermal relay is turned on, the resistor is burnt black, the capacitor is oiled .... Check screws, plugs, fuses which is broken or poor contact;The best way is to press the fuse or the plug, tighten the tips of the wires carefully. Sometime only by initial inspection also detect the damage, repairing the machine then it can operate as normal If there are no signs of damage, disconnect the power and check specifically. 3. Checking while power connection Turn on the circuit breaker and then observe the signal lights to see if the light is on or not. Press the START button to see if the relays and contactor is working or not. Is there an abnormal sound? Are the contacts ignited? Using a voltmeter measures voltage respectively from the circuit breaker, power meter, the wiring connection to the motor of each phase R, S, T to U, V, W ... the voltage must reach rated U or above/below 5% is qualified. In case the voltage drops a lot (only less than 85%) mean the problems is existed. If the voltage has 3 phases, reach the rated motor, rotary rotor, While the machine is operating , observe the ammeter:The best is to use the ammeter to measure the current of the three phases; The load current in any phase also can not exceed the rated value on the motor's label. Advice: when the engine uses 3-phase 380V electricity, every 1kw, needle ammeter indecates from 2 A or less mean that motor can operate. 4.In the case of an electric motor use an inverter, there are electronic circuits using a switch that does not have contact via thyristors and triacs. - This is very complicated case,it's hardly visible by eyes; the failures are often happened in the control circuit; capacitors; transistors or ICs; electronic relays In order to accurately determine, it is necessary to measure, the simplest way is to use a multimeter with a degree of accuracy from 0.5-1. Sequentially checking where the power supply is the primary coil of the transformer, the 4-bridge rectifier circuit takes one-way power (assuming 12V) to enter the transistor and IC amplifier stages. KS. Bùi Văn Yên
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