What are the frequent problems with relays and Auto Relay in use?
The range of use of relays is now more and more extensive, the more frequently used,the longer the time, there will be some problems, then on relays and automatic relays The more common problems are as follows:
The contact of the relay is faulty, which is more common. For most faults, about 70% of the faults occur on the contacts. It is important to select all the relay contacts.
First, the choice of AC and DC electromagnetic relays Almost all AC relays are caused by the humming caused by the armature vibration. When the voltage on the relay coil (or current) When the specified action value is not reached, the armature flutter will cause the contact to shake. If the contact is connected to the inrush current load, the arc caused by the chatter may be touched.
The point is melted or welded. Second, the relay operating voltage selection When the relay works, the coil should apply the rated
working voltage (current) instead of the suction voltage (current), thus enabling The electrical coil voltage (or current) has a mechanical voltage shock or ambient temperature rise when the power supply voltage (or current) fluctuates or the relay is used. The insurance margin of work. The suction voltage (or current) is only a parameter that the manufacturer limits the sensitivity of the relay and evaluates it.
The relay has different release voltages The bigger the better. When the relay is released, if the leakage current in the coil circuit is too large, the relay will not be released reliably. Third, the selection of relay load capacity and failure analysis relays will be the following kinds of loads when in use
1, capacitive load
The charging current of the capacitive circuit, the short-circuit discharge current starts at a large time,when charging or short-circuiting, the contact may be severely ablated due to too much charging current or Welding failure. In use, if the current limiting capacity can be connected in series according to the size of the capacitance,the hazard can be eliminated.
2, incandescent lamp load
Since the cold resistance of the tungsten wire in the incandescent lamp is very small, the inrush current at the instant of turn-on is as high as 15 times the steady-state current. Such a large inrush current will make the contact quickly. Corrosion, even welding failure.
3, motor load
The input impedance is very small when the motor is stationary, so the surge current is very large just after starting.
Due to the difference in motor load, its startup time has It can be short or long, so the startup surge current lasts for the same amount of time. In addition, the relay contact is used as the motor opening and closing switch, and the shutdown is continued. The electrical appliance must withstand the arcing caused by the high induced back voltage shock of the motor windings, so the insulation resistance level between the contact groups and the ability to withstand overload must be There
is ample surplus.
For more information on relays and automatic relays, please visit the official website of Wenzhou Anxun Electric Co., Ltd.: https://www.nicerelay.com.
The magnetic holding relay is a common type of relay, and it is also a new type of relay. In recent years, the development speed is fast and the usage rate is high. This automatic switch, like other electromagnetic relays, plays an automatic role on the circuit. Switch on and off. The difference is that the normally closed or normally open state of the magnetic holding relay is completely dependent on the permanent magnet, and the switching of the switching state is accomplished by triggering a pulsed electrical signal of a certain width.
WENZHOU NCR INDUSTRIAL CO.,LTD. is one of the core manufacturing companies of NCR Group. The magnetic holding relay developed by the company includes a base, a magnetic circuit part, a moving piece combination and a static combination. The magnetic circuit part and the base are connected by a push piece; The road part is composed of a coil frame, an armature assembly, a yoke iron, a iron core, a plastic splint and an excitation coil. The armature assembly is composed of a magnetic steel, a pole piece and a magnetic package insulator, and the pole piece, the yoke and the iron core in the armature assembly are formed in cross contact. Closing the magnetic circuit; the moving piece assembly comprises a connecting piece, a moving reed, a large split piece, a small splitter piece and a moving contact, the static piece assembly is composed of a static piece and a static contact, and the plastic clamping plate is provided with a hole, and the coil frame is arranged There are two lead legs, the inner and outer lead wires of the excitation coil are respectively soldered on the lead pins, the moving springs on the movable piece assembly pass through the holes at the front end of the push piece, and the protruding portion on the armature assembly passes through the hole at the rear end of the push piece, magnetic The wiring legs of the road part are connected to the positive and negative poles of the DC power supply.
Conventional magnetic holding relays have low sensitivity and require a large coil drive power when the contact assembly is closed.
Choose a high-quality relay, choose Zhejiang Anxun Electric Co., Ltd., the company website: https://www.nicerelay.com.
