An electric beam crane is a device mounted under the ceiling in the workshop building for transporting heavy loads. The crane crane itself is a fairly simple device. Below will be described the principle of its operation and device. The above diagram is typical, but as a basis it is suitable for any similar equipment. The electrical circuit for connecting the crane beams depends on the method of supplying power to the mechanism. It can be wired or brush.
Description of the electrical circuit
We will start work on our crane beam by supplying power to the control circuit by turning on the QS1 switch. Typically, QS1 is a turnkey switch designed to prevent unskilled persons from working with the lifting gear. After turning on the control circuit, we begin to work with the mechanism.
The scheme of the electric crane-beam is presented below.
Winch control
When the SB1 button is pressed, the power passes through the current relay, the normally closed contact of the limit switch and the contact of the KM2 starter turn on the KM1 starter electromagnet. The KM1 starter supplies power to the M1 engine, as a result of which the load is turned on. A current relay (RT) is necessary in order to prevent prolonged operation of the motor in overload mode. A limit switch is necessary to stop rotation when the hook reaches the maximum upper position in order to avoid damage to the winch or its drive. The power supply of the KM1 starter is passed through a normally closed contact of the KM2 starter to avoid their simultaneous switching on. If this is not done, then if 2 starters are turned on at the same time, a short circuit will occur in the power part of the circuit at the contact areas of the contact groups, which will disable them. Such starter switching circuits are called deadlock circuits.
In order to lower the load, press the SB2 button. When pressed, the current passes through a normally closed contact of the limit switch of the extremely low position. And the normally closed contact of the KM1 starter, passing through the coil of the KM2 starter, starts the reverse rotation. A limit switch is necessary to avoid rewinding the cable.
Hoist control
To move the hoist of the crane beam electric, relatively speaking, to the left, press the SB3 button. The current will flow through the normally closed contact of the limit switch located on the left extreme point of the hoist. When the telpher reaches the leftmost position (collision with a rubber buffer), it will cut off the power supply of the KM3 starter to avoid overloading the motor and excessive wear of the wheels due to their rolling in place. KM3 starter power is also provided through a normally closed contact of the KM4 starter for the same purpose of protecting starters from being switched on simultaneously.
To move the hoist, relatively speaking, to the right, press the SB4 button. The supply voltage will go to the normally closed contact of the limit switch, and after passing through it, it will go to the normally closed contact of the KM3 starter, and only after that it will energize the coil of the KM4 electromagnet, which will turn on the reverse rotation of the motor. If the right extreme point collides with the right buffer, the limit switch will cut off the starter power supply, as a result of which the wheel rotation will stop.
Electric bridge crane control
To turn the bridge forward, press the SB5 button. The starter is powered in the same way as in the previous functions to provide the same protections. The reverse travel of the bridge works in the same way.
At the end of work with the mechanism, turn the key to the "OFF" position and extract from the castle. When you try to turn on any of the functions of the electric crane, the mechanism will remain stationary.
In conclusion, we can say that the crane beam is one of the simplest devices, but it greatly facilitates the work of an ordinary worker.