Big DC Motor

• Performance

d. Duty: Continuous (SI);
e. Armature and field circuits for motors may be either operated on static thyrisier controlled supplies, or from d-c generator;
f. Performances of motors all comply with State Standard GB755.  Fundamental technical rules for electrical machines.
2. Standard rated voltage: 160V or 440V, Values for  220V, 400V, and 660V or other voltage may be derived on request.
3. Rated speed: 3000, 1500, 1000, 750, 600, 500, 400, 300 and 200 r/min, totally nine grades. Decrease armature voltage to make speed regulating under constant torque, lowering down field voltage to make speed regulating at constant output. Speed regulating range: see technical date. The torque can be remained constant by reducing speed via armature voltage weakening below raced value. It is stipulated that armature speed range can be down to the lowest 20 r/min at constant torque and stable running.
4. Separate excitation is the basic excitation type of the motors. Nominal field voltage: 180V.
Other excitation voltages are also acceptable on request. Forced excitation is allowed with the voltage of less than 500V. When a motor is normally running, its excitation current must not be higher than rated excitation current. To assure the reliability of insulation of excitation system, the motor must be protected against self induced voltages by a release resistor connected in parallel with the excitation circuit of the motor is  interrupted. At rated field voltage the value of shunt resistor is about seven times filed winding resistance (cold state). While the field voltage is higher than nominal voltage, the value of shunt resistance may be lower than seven times field resistance, otherwise higher than seven times.
5. For frame size Z4-315, Z4-355, Z4-400 and Z4-450, compensating windings are provided. For frame size Z4-250 and Z4-280 the motors are feasible with a compensating winding too.
6. A marked earthing terminal is provided forth motors.
7. The efficiencies listed in the date sheet are for rated output, voltage and speed, and include excitation lose, excluding that of separate ventilating fans.

• Features and application

The motors can be lastingly operated form fully controlled three-phase bridge without a smoothing reactor. Motors for 160V may be operated on single-phase bridge thyristor. In that case, a smoothing reactor, whose inductance is specified in the relevant technical date, should be inserted in the armature circuit to suppress ripple current.

Z Series Big DC Motor is for mill auxiliary in metallurgical industry, metal cutting machine-tool, paper making, print, textile