Operators must be familiar with the basic working principles and functional characteristics of Siemens

 frequency converters, and have knowledge of electrician operation. Before daily maintenance of the 

frequency converter, it is necessary to ensure that the overall power supply of the equipment is completely 

cut off; And wait for 3 to 30 minutes after the display of the frequency converter completely disappears

 (based on the power of the frequency converter) before proceeding. Attention should be paid to checking

 the voltage of the power grid, improving the surrounding environment of the frequency converter, motor, 

and circuit, regularly removing dust inside the frequency converter, and minimizing the failure rate of the 

frequency converter by strengthening equipment management.

What is dew point? What is the pressure dew point?

The temperature at which unsaturated air lowers its temperature while maintaining a constant partial pressure 

of water vapor (i.e. maintaining a constant water content) to reach saturation is called the dew point. When the

 temperature drops to the dew point, condensed water droplets precipitate from the moist air. The dew point 

of wet air is not only related to temperature, but also to the amount of moisture in the air. A high moisture

 content leads to a high dew point, while a low moisture content leads to a low dew point. After wet air is 

compressed, the density of water vapor increases and the temperature also increases. When compressed air

 is cooled, the relative humidity increases. When the temperature continues to drop to 100% relative humidity, 

water droplets precipitate from the compressed air, and this temperature is the pressure dew point of the

 compressed air.

What is the relationship between pressure dew point and atmospheric dew point?

The correspondence between pressure dew point and atmospheric dew point is related to the compression

 ratio. Under the same pressure dew point, the higher the compression ratio, the lower the corresponding 

atmospheric dew point. For example, when the dew point of compressed air pressure at 0.7Mpa is 2 ℃, the 

corresponding atmospheric dew point drops to -28 ℃.

What is the dew point measured by?

Although the unit of pressure dew point is ℃, its connotation is the water content of compressed air. Therefore, 

measuring dew point is actually measuring the moisture content of air. There are many instruments for measuring

 the dew point of compressed air, including mirror dew point meters with nitrogen, ether, and other cold sources, 

and point hygrometers with electrolytes such as phosphorus pentoxide and lithium chloride. At present, specialized 

gas dew point meters are commonly used in industry to measure the dew point of compressed air. Use a dew point 

meter to measure the pressure dew point of compressed air. The sampling point should be placed in the exhaust 

pipeline of the dryer, and the sample gas should not contain liquid water droplets. The dew points measured at 

other sampling points all have errors.