Views:1 Author:Site Editor Publish Time: 2020-07-17 Origin:Site
Traditional crane controllers are outdated because of their many drawbacks and are highly vulnerable to safety hazards. The pendant crane control system has a variety of protection functions, which have improved the various drawbacks of lifting operations to varying degrees. I will introduce you to the method of maintaining pendant crane control.
Protection function of pendant crane control system
About the maintenance of pendant crane control
In the main circuit of the line, there are a total contactor and a contactor. In addition to the function of the on-off line, they also have various protections such as short circuit, overload and undervoltage. The driver can control the total contactor through the start/stop button in the linkage table to control the on/off of the main power supply. In the case that the contactor cannot be switched on and off, the shunt trip coil of the main breaker can be turned on by the emergency stop switch. To disconnect the power circuit. In addition, a limit switch and a key switch are also provided in the main power control circuit as safety protection measures.
The system has the following protections: upper and lower limit protection, upper and lower pre-limit protection, overspeed protection, overload protection, zero protection, power supply voltage phase failure protection, motor phase loss protection, voltage loss protection, device overcurrent protection, grounding protection, etc. At the same time, the frequency conversion device itself should have the status and fault indication, and the fault signal is stored in the memory unit, and the fault signal can be saved even when the power source has a problem: after the protection, it is necessary to ensure that the lifting object is safe and does not slip. Hooks and other dangerous conditions.
The emergency power-off switch has an emergency power-off button on the power distribution protection cabinet of the crane and the linkage table of the driver's cab. The emergency power and control power can be easily cut off in an emergency. The pendant crane control control button signal should be sent to the PLC device for monitoring and action recording.
Zero protection, zero position contact on the crane's cab console and the remote control handle, through its interlocking relationship with the PLC, to achieve the purpose of zero protection. When the mechanism starts to operate and loses power after the power is restored, the pendant crane control handle must be placed in the zero position before the motor of the mechanism can be started.
The travel switch has a travel switch in the crane running mechanism, the trolley running mechanism and the lifting mechanism; the travel switch controls the various mechanisms through the PLC; and the upper and lower pre-limit switches are also provided in the lifting mechanism. When the hook runs to a certain distance before the limit position, the pre-limit switch operates, and the running speed of the hook automatically decelerates to reduce the impact at the end limit.
The lifting limit position limit protection is equipped with a lifting mechanism to set the rising limit position limiter to ensure that when the lifting device is lifted to the limit position, the lifting power source is automatically cut off, and an alarm signal is sent through the PLC.
The most important thing is the daily inspection of the pendant crane control. Daily inspection can detect the failure of the equipment early to ensure the safety of the operation. If you find any doubts about the operation, stop the operation immediately and use it after troubleshooting. Method: Press the emergency stop button for three seconds to check whether the transmitter power is sufficient, check whether the emergency stop is normal, test the crane, the gantry crane and its limit switch function are normal. At the time of testing, the STOP emergency stop button is ready to prevent the limit switch of the driving limit, and there are no limit switches for many driving actions. Therefore, the lower limit test cannot be performed, otherwise all the steel cables will fall.
For other situations, reasonable operation can better protect the pendant crane control. If the transmitter has insufficient power and exceeds the remote control distance or is seriously disturbed, there may be a slow or delayed operation. Stop operation at this time. Ordinary batteries have lower battery performance at temperatures below 10°C. The battery may stop output below 0°C. At this time, the low temperature battery should be replaced. Such as mercury batteries, nickel-metal hydride batteries. When not in use for a long time, remove the battery. Replace the transmitter protection rubber sleeve regularly. Please remember the emergency situation before use.
What you need to know is that the correct operation of the day is important, but you can't ignore the usual maintenance and management whether using pendant crane control or wireless crane control. If you have more questions, please let us know and we will answer your questions. We also provide Rainproof pendant crane control, Bridge crane pendant control, want to know more, just click us.