Interpretation of those unspoken rules in the screw air compressor industry! The following terms may seem familiar, but do you really know what specific extended meanings they contain? You can't eat a big loss at a glance, maybe there is really a truth that scares you after reading it? Hehe~~~ Zhigao screw air compressor to find us Hunan Ruisheng electromechanical equipment, our official website is www.hnzega.com.
Interpretation of those unspoken rules in the screw air compressor industry! The following terms may seem familiar, but do you really know what specific extended meanings they contain? You can't eat a big loss at a glance, maybe there is really a truth that scares you after reading it? Hehe~~~
Zhigao screw air compressor to find us Hunan Ruisheng electromechanical equipment, our official website is
www.hnzega.com.
1. The past and present life of the motor service coefficient
a) Place of origin of the motor service factor. The "service factor" of the motor comes from the "MG1-2009 Motor and Generator Part" standard compiled and published by the National Electrical Manufacturers Association (NEMA), commonly known as the NEMA MG1 standard. (Service Factor, abbreviated as S.F)
b) What is the motor service factor? The service factor of an AC motor is a multiplier. When it is multiplied by the rated power, it indicates the power load that is allowed under the conditions specified by the factor of service.
c) What is the effect of the motor service factor on the continuously running motor? The motor will reduce the expected service life when running continuously at any service factor greater than 1. Insulation life and bearing life will be reduced compared to operation at rated nameplate power.
d) What is the motor service factor said in the air compressor industry? The current air compressor industry said motor service coefficient its content has far exceeded the original meaning of the standard, is a real large charge of small non-standard motor, the purpose is to flaunt the motor small gas volume large energy saving, a measurement of motor current is exposed, at present this "motor service coefficient" has become the industry's unspoken rules, a difficult to get rid of the stubborn disease.
e) The impact of motor service coefficient on the safe operation of the air compressor, it is difficult for the user to know its actual motor power before purchase, and there is no way to know its operating current, resulting in the subsequent switch cabinet, power cable or other power supply equipment matched for the air compressor The optional capacity is too small, which brings great hidden dangers to the safe operation of the air compressor in the future.
2. Specified working conditions< br / >
The prescribed working conditions are the working conditions specified by the standard. The purpose of setting the specified working conditions is to facilitate the assessment of products and the fair comparison of various products, which is used for assessment rather than actual use of working conditions.
Main content:
1) Suction pressure 0.1MPa;
2) Suction temperature 20°C;
3) The relative humidity of the inspiration is 0;
4) Cooling water temperature and water volume;
5) The exhaust pressure is rated exhaust pressure
It is used when making corrections during the test calculation, and the atmospheric pressure of 0.1MPa and the suction temperature of 20 degrees Celsius cannot be set to the fixed parameters of the flow meter when the flow meter parameters are set, and it is important to note that this setting is wrong.
3. The oil content of compressed air is ppm. It indicates the content of a trace substance in the mixture, which is often said to be the expression of trace concentration, which indicates the concentration content of parts per million: the industry said that ppm is the weight ratio, under the condition of atmospheric pressure of 0.1MPa, atmospheric temperature of 20 degrees Celsius, atmospheric relative humidity of 65%, 1ppm is equivalent to 1.2 mg of oil per cubic meter of air.
Second, the new standard for stupid and unclear
It has been almost a year since JB/T 6430-2014 was introduced, have you really understood the new standard? What are some subtle changes from the old 2002 standards that are often overlooked? The content of this issue will explain in detail the imperceptible changes of the old and new rules from the following, and the usually careless "fools" will not thank you after reading ~~ Hurry up to see if the equipment meets the new standard.
1. Added 0.3MPa and 0.5MPa two rated exhaust pressure gears
2. The nominal volumetric flow rate under the rated exhaust pressure and drive motor power has been improved, and the nominal volumetric flow rate has increased by 0.5-1.5m3/min on average.
3. When the actual motor power is greater than the drive motor power or motor service coefficient > 1 specified in the standard, its nominal volume flow rate should be calculated by linear proportional interpolation.
4. The noise power level index of the unit has been reduced by 2 decibels.
5. Added 3 necessary automatic protection devices, and required to alarm or automatically stop
a) Exhaust pressure exceeds the limit; b) Exhaust temperature exceeds the limit; c) Motor overload, especially exhaust pressure overrun alarm or automatic shutdown, many manufacturers have not yet set this function.
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