Explosion-proof motor is a kind of motor which can be used in flammable and explosive places. Explosion-proof motors are mainly used in coal mine, petroleum and natural gas, petrochemical and chemical industries. When the manufacturer is choosing explosion-proof electric machine, which factor should notice?

　　The following factors should be paid attention to when choosing explosion-proof motors:

　　1. After determining the voltage, frequency and speed, select the installation coefficient K to determine the motor power according to the motor's load and power supply network status. Check the mounting dimensions from the motor sample by mounting method. There are also cases where the motor power is first selected from the identified center height from the sample.

　　2. Confirm whether the technical indicators meet the requirements (both parties are required to confirm in the technical agreement). For the wound rotor motor, in order to select the matching start and speed control system, the supplier shall provide the value of rotor voltage U2 and current I2.

　　3. Determine the protection grade and types of explosion protection, explosion protection grade or corrosion resistance, and other requirements, such as outdoor and Marine. Reference: explosion-proof motor temperature group and explosion-proof type.

　　The following three points should be noted when selecting the explosion-proof motor:

　　1. The flameproof motor can meet the requirements of flammable and explosive environment. Do not choose high grade motor.

　　2. Determine the technical indicators according to the actual use situation. The higher the target, the higher the cosine, the better and save power, while the other indicators are not the same. For example, drive the motor of axial flow pump and fan, the Tst can be within the range of 0.6~0.8, Tm does not need to be high, 1.6 or so can meet the use requirements. If the buyer is a little bit loose on these two indicators, the designer can make up the excess function from this to the Ist, that is, to lower the Ist. This is very practical for small network capacity use place. The load of the diode motor is mostly fan and pump. If the manufacturer pursues this index too much, the upper part of the groove shape of cast aluminum rotor is designed very narrow, which adds unnecessary difficulty to the manufacture. In use, there are many faults caused by broken bars and strips.

　　3. Select appropriate protection level. The difference between IP54 and IP44 is mainly on the dustproof function. In order to save money, some buyers choose the motor of IP44 in the place of IP54, causing premature damage to motor bearings. On the contrary, when the IP44 meets the requirements, P54 is not required. The latter should be equipped with rubber sealing ring, maintenance is not as good as the former.