CHINA FACTORY HIGH VOLTAGE ELECTRIC MOTORS LOW STARTING CURRENT, LARGE LOAD INERTIA WITH AIR-WATER COOLED YCH, YGF. CHINA PLANT HIGH VOLTAGE ELECTRIC MOTORS FOR (SUGAR, STEEL, CEMENT) PLANT, PUMP, FAN, DRUM-BALL MILL, POWER PLANT

 1. General Description YCH、YGF series three-phase induction motors with low starting current and high load inertia are our newest products developed in 1990's, manufactured with the technology introduced from Westinghouse Electric Corporation / USA and featured by light weight, com. pact volume, reasonable construction, less material, excellent workmanship, high efficiency, low starting current, high load moment of inertia (permissible of a moment of inertia of the driven load as great as 2.5 times that as per the NEMA standard or 7times that as per the IEC standard), low noise, small vibration, good reliability and convenience for installation and maintenance. YCH、YGF series three-phase induction motors with low starting current and high load inertia have won good reputation from the clients and are warmly received since the operation in 1991. Almost all the motors for catalytic cracking installations in petrochemical industry of China were manufactured by us, therefore, this series of motor was listed in " Catalogue for National Products Replacing Imported Equipment" by China National Petroleum Chemical Machinery Corp. YCH、YGF series three-phase induction motors with low starting current and high load inertia are updated products based on 710-4,800-4,900-4 of YCH、YGF standard series.Through continuous summarizing and improving,developed YCH、YGF1000-4 and after YCH、YGF1000-4 series’nearly 10 years of realiable operation and taking the clients’demand in consideration,the company have developed YCH、YGF1120-4 series with 30000kw as its largest output.  2.Structure Description      The motor of series YCH、YGF 1000 - 4 is of enclosed squirrel cage type with air - water cooler, protection degree of IP44 in nermal, cooling method of 81ICW, mounting type of IMB3( horizontal mounting ) .      The motor is generally of a box type structure and floor mounting. End bracket and pedestal type sleeve bearings are adopted. The bearing has a integral round bracket, the upper half of which is equipped with a small end cover for convenience for installation, inspection and maintenance. The stator frame is of a fabricated box construction which is tight in weight and high in regidity.       This series of motors has a cylindrical shaft extension, coupled with a single key. The rotation direction is clockwise viewing from the shaft extension end, counter clockwise rotation as well as dual shaft extensions and tangential keys are also possible upon order's request.      Class F insulation material is used for the stator winding and the end potion is securely fixed and bound. After several times of voltage impulse test between turn to turn and voltage endurance test to the ground during manufacturing process and vacuum pressure impregnation ( VPI ) treatment with solventless varnish and sometime also anti - corona treatment upon customer's requirements, the motors have a retiable insulation performance, high mechanical strength and anti - moisture ca- pability.      Copper with food weldability and high strength is used for the rotor conducting bars. Advanced and reliable medium -frequency welding technoloty is adopted to connect the con-ducting bars and the end rings. In slot positioning measure is made to prevent the rotor bars from movement.      The main terminal box with protection degree of IP44 is generally installed on the right hand of the motor (viewing from shaft extension end) , and also can he on the left hand according

to customer ' s requirements. In addition, main terminal box can be equipped with some protection devices (such as current transformer and lightening arrestor ect.)      The motor is equipped with a space heater, the motor is provided with a temperature control device in order to prevent the surface of the heater form overheating. Both the stator winding and the bearing bushes are provided with temperature detecting elements, PT100. The stator flame is provided with air inlet and air outlet thermometers so as to ensure a reliable operation of the motor.  3.Starting of the Motor      Advanced computing technology is used to calculate the starting current, starting time , temperature rise of stator winding , temperature rise of rotor bars and temperature rise of end rings in order lo protect the motor from early damage due to excessive starting load. In system designing, it's recommended for the customer to check l ) the moment of inertia of the rotating parts of the driven machine (converted to the rated speed of motor) not exceed the value J ( load ) listed in the technical date table. (Notice: J = 1 /4GD2) 2) the line voltage measured at the terminals of the motor during starting period not less then 85% of the ratings.  3 ) The characteristics of the resistance moment of the driven machine are pump - like or blower - like ones, and at rated speed the resistance moment converted to the motor side not exceed 35% of the rated torque of the motor.      Under abover-mentioned conditions, the motor is permitted to be started consecutively twice under actual cold state (natural coasting down to still between two starts) , or once under hot state. Additional starts after the above mentioned should be made 4 hours later after the motor is shut down.           In the following cases, please consult the manufacturer in advance and a special order should be placed in order to guarantee a reliable operation of motor:  l ) It's requested that the mass moment of inertia of the mechanical rotation part driven by the motor is to exceed the J value presented in the technical data table. 2) The network short - circuit capacity is relative small. 3 ) The lowest terminal voltage of the motor is lower than 85% of the ratings.  4) The characteristics of the resistance moment of the driven machine is not pump - like or blower - like. 5 ) At rated speed the reistance moment converted to the motor side is greater than 35% of the rated torque of the motor in spite of pump - like or blower - like characteristics of the re- sistance moment.  5.Application      This series of motors is mainly applicable as prime drivers in power plants, mines, petrochemical industry and steel works elc. to drive compressors, blowers, water pumps and other mechanical equipment. This series is especially suitable for driving the catalytic cracking installations in petrochemical industry and blast furnace blower sets in metallurgical industry.  6. Attention for Ordering The following parameters should be specified when placing an order