The key points for selecting and daily maintaining the control box of an electric hoist are as follows: Key Points for Selection 1. **Specification and Power Matching**    - **Consider Electric Hoist Parameters**: Select the control box according to parameters of the electric hoist such as the rated lifting capacity, lifting speed, and running speed. For example, an electric hoist with a large lifting capacity requires a control box with a larger capacity and stronger overload capacity.    - **Match the Motor Power**: The rated power of the control box should be matched with that of the electric hoist motor. Generally, the rated power of the control box should be slightly larger than that of the motor to ensure that the control box can supply power stably and control the motor during startup and operation, avoiding problems such as overload burnout. 2. **Control Function Requirements**    - **Basic Control Functions**: Ensure that the control box has the basic control functions required by the electric hoist, such as control buttons or handles for functions like lifting, lowering, and left - right movement, and the operation should be simple, intuitive, and convenient.    - **Selection of Additional Functions**: According to the actual usage scenarios and requirements, consider whether some special functions are needed. For example, the limit protection function can prevent the electric hoist from exceeding the limit position and causing safety accidents; the variable - frequency speed - regulation function can achieve precise control of the running speed of the electric hoist to meet the needs of different working scenarios. 3. **Protection Class Requirements**    - **Usage Environment Factors**: If the electric hoist is used outdoors or in harsh environments such as humid and dusty conditions, the control box requires a high protection class. For example, in construction sites with a lot of dust, a control box with a protection class of at least IP54 should be selected to prevent dust from entering and prevent splashing water from affecting the normal operation of the control box.    - **Water - proof and Moisture - proof Performance**: For environments where there may be contact with water, such as docks and hydropower stations, the control box needs to have good water - proof and moisture - proof performance. A control box with a protection class of IP65 or above can be selected to effectively prevent water from entering and protect the internal circuit components. 4. **Brand and Quality**    - **Preference for Well - known Brands**: Choose brands with a good reputation and market credibility. These brands usually have more reliable guarantees in terms of product quality, technology research and development, and after - sales service. International brands such as Siemens and Schneider, as well as well - known domestic brands such as Chint and Delixi, generally produce control boxes with relatively stable quality and performance.    - **Product Quality Certification**: Check whether the control box has passed relevant quality certifications, such as the 3C certification. This is an important symbol that the product meets national safety standards and quality requirements, ensuring that the control box reaches a certain level in terms of safety and reliability. 5. **Price and Cost - effectiveness**    - **Budget Consideration**: On the premise of meeting the usage and quality requirements, select a control box with a suitable price according to the project budget. Do not blindly pursue high - priced products, nor choose low - quality products to save costs. Instead, consider the cost - effectiveness comprehensively.    - **Long - term Cost Analysis**: In addition to the purchase price, also consider the long - term use cost of the control box, including energy consumption, maintenance cost, and service life. Some control boxes with a relatively high price but reliable quality, low energy consumption, and low maintenance cost may have a higher cost - effectiveness in the long run. Key Points for Daily Maintenance 1. **Cleaning and Inspection**    - **Regular Cleaning**: At regular intervals (such as weekly or monthly), use a clean soft cloth or brush to clean the dust and debris on the surface of the control box to keep its appearance clean. For the interior, tools such as a hair dryer or vacuum cleaner can be used to carefully clean the dust inside when the power is off, preventing dust accumulation from affecting heat dissipation and causing circuit failures.    - **Appearance Inspection**: Before each use or during regular inspections, check whether the housing of the control box has damage, deformation, corrosion, etc. If there are problems, repair or replace it in a timely manner. Check whether the door of the control box can be closed and locked normally to ensure its protective performance.    - **Circuit Inspection**: Regularly check whether the circuit connections inside the control box are firm, and whether there are any phenomena such as looseness, oxidation, and damage. For loose terminal connections, tighten them in a timely manner; for oxidized or damaged circuits, handle or replace them in a timely manner to prevent problems such as poor contact and short - circuits caused by circuit issues. 2. **Function Testing**    - **Operation Function Testing**: Regularly test the various operation functions of the control box. For example, press buttons such as lifting, lowering, and left - right movement to check whether the electric hoist can respond normally and whether the movements are accurate and smooth. At the same time, test whether the emergency stop button is effective to ensure that the power can be cut off quickly in an emergency and stop the operation of the electric hoist.    - **Protection Function Testing**: Regularly test the various protection functions of the control box. For example, for the limit protection function, manually simulate the situation where the electric hoist reaches the limit position to check whether the limit switch can act in a timely manner and stop the operation of the electric hoist. In addition, also test whether functions such as overload protection and short - circuit protection are normal to ensure the safety of the electric hoist and operators. 3. **Temperature and Ventilation Inspection**    - **Temperature Monitoring**: Pay attention to the temperature of the control box during operation. Tools such as a thermometer can be used to regularly measure the internal temperature of the control box. Generally, the internal temperature of the control box should not exceed the specified upper limit value (such as 60℃). If the temperature is found to be too high, check the cause in a timely manner. It may be due to poor heat dissipation, excessive load, or internal component failures.    - **Ventilation Inspection**: Ensure that the ventilation openings of the control box are unobstructed and free of debris to ensure good heat dissipation. Regularly clean the dust and debris around the ventilation openings. If necessary, install a cooling fan or improve the ventilation environment to prevent the internal components of the control box from being damaged due to overheating. 4. **Maintenance of Electrical Components**    - **Contactor Maintenance**: Check whether the contacts of the contactor have wear, ablation, etc. If there is slight ablation, it can be repaired with sandpaper or a file; if the wear is severe, the contacts should be replaced in a timely manner. At the same time, check whether the electromagnetic coil of the contactor is normal, and whether there are problems such as overheating and short - circuits to ensure that the contactor can be normally attracted and disconnected.    - **Relay Maintenance**: Regularly check the relay, check whether its contacts are in good contact, and whether there are phenomena such as adhesion and oxidation. Check whether the action of the relay is sensitive and reliable. The response of the relay can be tested by inputting a simulated signal. If there are problems, replace or repair it in a timely manner.