Elevator electrical maintenance fault measurement method - Database & Sql Blog Articles

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When the elevator fails, it should first be distinguished whether the mechanical fault is not an electrical fault. Generally come and go, mechanical failure is relatively intuitive, and easy to find early. Electrical faults are more complicated. In addition to inspection, the circuit needs to be measured. The measurement methods are as follows:

1) Measuring resistance method

When the switch contact is poorly connected or the line is broken, the multimeter resistance file can be used for measurement. The measurement should be performed when the line is powered off. If the contact of the switch contacts is good, connect the multimeter's test leads to both ends of the line, and then short-circuit the two ends of the tested switch contacts with a wire. If the multimeter resistance file indicates a small number or a path, the switch is the fault point. When measuring whether a long wire is broken, you can ground one end of the wire and measure the resistance of the other end of the wire to the ground with a multimeter. If it is not clear, the wire has a break.

2) Measuring voltage method

The measurement voltage method needs to be performed with power in the line. The DC voltage is measured with a DC gear, and the AC voltage is measured with an AC gear, and the line voltage is in accordance with the multimeter's voltage range digital indication range. If the contact of the switch contacts is good, the multimeter pen can be touched at both ends of the contact to be tested. If there is an indication on the multimeter, the contact is not connected. If there is no indication, the contact has been turned on.

3) Short circuit method

In the absence of a multimeter, an insulated wire can be used, and the insulation layer is removed at both ends to expose the wire. The wire is connected to the switch contacts connected in the circuit to make the circuit connected, and observe the action of the control line relay to determine the fault point. When using this method, special attention should be paid to safety. This method should not be used for main circuits with large currents to prevent accidents caused by currents during contact. For microcomputer-controlled elevators, this method is usually not used to avoid damage to the equipment.

4) Test light method

Connect the lamp to the cable and install a 220V incandescent bulb to measure the charging of each point of the circuit. When measuring, ground one end of the test lamp (neutral line), the other end touches the conductive part to be tested, observe the light-emitting condition of the light bulb, and judge the fault. When measuring the 220V circuit, the bulb is fully illuminated. When measuring the 110V circuit, the bulb is only half bright (except for the series coil). When using the test lamp, a lamp with a smaller wattage should be used. The test lamp should be ignited in the area where there is electricity before use to confirm that the test lamp itself is intact.

5) Signaling method

Use a battery to connect the low-voltage (3V) caller in series, and use the sounder to make a sound, and measure whether the line and switch contacts are connected. This method should also be carried out in the event of a line outage. This method can only test whether the line is in the path. Because the capacity is small and the voltage is low, the line with the coil is not suitable for use.

6) Electroscope method

Use a commercially available low-voltage electroscope to measure the voltage at each point of the circuit, and determine the fault is one of the most common methods. Please pay attention when using:

a. When using the electroscope to measure, it should be done with line power.

b. Before using the electroscope, check the electroscope on the confirmed electrified body to prove that the electroscope is in good condition. Prevent accidental judgment caused by bad electroscope, and an electric shock accident.

c. In the elevator electrical circuit, the highest ground voltage is 220V, and the DC control part is 110V. The electroscope resistance is relatively large. When measuring, the brightness of the tube is dark. You can touch one of the hands without the pen, touch the unpowered control cabinet or other metal parts that have been grounded, in order to increase the brightness of the tube to improve the test. Electrical effect.

d. When measuring a 380V circuit with a coil (such as a transformer) with an electroscope, the A-phase fuse sometimes blows, but the underside of the A-phase fuse still makes the manifold bright, which is due to phase B or C. The phase power is returned to the result here via the coil. Therefore, this factor should be taken into account when measuring the circuit with an electroscope.