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Elevator Supplier Share What Is Ac And Dc Contactor

  • Street: NO.688, Lianxi road, Nanxun, HuZhou city, Zhejiang Province, china
  • City: HuZhou
  • State: Arizona
  • Zip Code: 313000
  • Listed: December 24, 2018 9:55 pm
  • Expires: 61 days


After some basic common sense is available, it can bring a lot of conveniences and ideas to elevator engineers. Let’s take a look at the basic common sense of the elevator with the Elevator Supplier :

First of all, their work is based on the same foundation. The coils are energized to generate a magnetic field so that the moving armature pulls the switch to turn on and off.

The difference is one: one through the alternating current, one direct current; the other two: the direct current contactor coil has a larger amount of wire than the alternating current contactor coil; and the third: the core of the alternating current contractor has a short circuit ring and the direct current contractor does not. The following is a description of the principle.

To understand the difference, the key is to understand the characteristics of the AC and the characteristics of the coil. China’s mains supply is 50hz, which means that 50 cycles change in one second, and 100 instantaneous currents are zero.

The resistance of the coil is very small. In the DC power supply loop, the winding exhibits a resistance characteristic, that is, the voltage drop is determined by the resistance of the coil, and has nothing to do with the inductance. Therefore, the coil needs to be a little more to make the resistance value larger, so as not to burn the power supply.

In the AC power circuit, the coil has an inductive reactance characteristic, and a voltage drop is generated by the inductive reactance. At this time, the resistance value can be zero, so the number of turns can be different as the DC contactor, and the line is thicker.

The core of the AC contactor has a short-circuit ring because the AC current flowing through the AC contactor coil has a zero current. When the current is zero, there is no magnetic field in the coil, so the moving iron core will be released without waiting. When it leaves, there is a current in the coil, which is sucked again, so that the suction, release, and suction are repeated. There are a hundred repetitions in one second, which creates noise. To eliminate this noise, the engineer came up with a way to embed a short-circuit ring on the core that is equivalent to a closed coil. An induced magnetic field is generated in the zero-time short-circuit loop, which causes the magnetic field in the core to become a continuous magnetic field, thus eliminating noise. During use, if this short-circuits ring breaks, the noise will appear. In noise-sensitive areas, sometimes the contractor is replaced for this reason, not because the contact is broken.

According to the above reasons: the amount of copper used in the DC contactor is high, the noise is low, and the cost of the AC contactor is low.

A simple judgment of electrolytic capacitors: In the process of repairing the elevator, some computer boards often encounter failures. In some cases, some serious losses can be avoided by careful observation. On the surface, the computer board is faulty. In fact, it may be an Only the capacitor failed, and the cost of replacing a capacitor was a few dollars, and it was sent to repair the computer board for hundreds of thousands. Simply observe whether the end face of the electrolytic capacitor has bulged, and if it is tamped, it will solve the problem after replacing it. There is also a way to dial the digital multimeter to the buzzer file, and use the red and black test leads to cross-measure the positive and negative electrodes of the electrolytic capacitor. If there is a short beep, the capacitor is good.

The lightning-proof grounding pole of the lightning rod and the grounding pole of the three-phase five-wire system cannot be mixed together. After a day of lightning and thunder, the elevator of an office building in Harbin is shut down and the person is arrested at the scene. It was found that the computer board was broken down in a large area. After careful inspection, the lightning bolt of the building was welded together with the steel bars of the main body of the building, and the grounding pole of the three-phase five-wire system was also welded together, causing the lightning current to pass through the lightning protection. The flat iron was poured into the control system of the elevator, causing serious damage to the north of the control system.

information about Elevator Supplier : https://www.fujihd.net/

Ad Reference ID: 195c21a9fb38bd3

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