The main products

Spare parts spare parts, the DCS control system of PLC system and the robot system spare parts,

Brand advantage: Allen Bradley, BentlyNevada, ABB, Emerson Ovation, Honeywell DCS, Rockwell ICS Triplex, FOXBORO, Schneider PLC, GE Fanuc, Motorola, HIMA, TRICONEX, Prosoft etc. Various kinds of imported industrial parts

BENTLY 3500/40M 176449-01 Monitor module

The speed of a DC motor is altered with the armature voltage. The range up to the point where the rated armature voltage is reached is referred to as the armature operating range. To enable the motor’s speed to be increased above these rated armature voltage, the field’s magnetic flux has to be reduced. This is done by reducing the field current. This operating range is referred to as the field weakening range. The behavior of the current controller in these operating ranges is depend on current controller operating mode.

I 2t function The DCS400 is equiped with an I2 t-protection for the motor, which can be enabled if required. Parameter Arm Cur Nom (1.01) is the 100% value for the current. All current depending values are related to this parameter. The I2t-function is enabled if the parameters Overload Time (3.05) and Recovery Time (3.06) are set to a value higher than 0 seconds and the overcurrent in parameter Arm Cur Max (3.04) is set to a value higher than the Arm Cur Nom (1.01). The function is disabled if the parameter Overload Time (3.05) = 0 s, or Recovery Time = 0 s, or Arm Cur Max (3.04) = Arm Cur Nom (1.01). If the recovery time is set to a value too low compared to the overload time, the alarm message Par Setting Conflict (A16) "Recovery Time to low" is generated. In addition to the overcurrent parameters the reference limititations Torque Lim Pos (3.07) and Torque Lim Neg (3.08) have to be set. It has to be ensured that the parameterized overload times correspond to the overload capability of motor and drive. This has already to be taken into account during the selection process of the drive system.

Stall Protection

A second parameter set is available for the speed controller (Alternative Parameters), which can be activated through events. The speed controller parameters KP and TI and the parameters for the accelerating and deccelerating ramps are switched over. Depending on the speed actual value or the speed deviation (difference between speed actual and speed reference) the behaviour of the speed controller can be influenced. In this way different behaviour during acceleration and decceleration can be parameterized easily.

The stall protection of the motor can be activated with the Stall Time (3.18) parameter. If the value of this parameter is 0.0s the stall protection is switched off. A time >0.0 s switches the stall protection on. The following conditions must be fulfilled to trip the monitor: The actual speed value is smaller than the value in Zero Speed Lev (5.15) and the actual torque value is bigger than the value in Stall Torque (3.17) for a time longer than the value in Stall Time (3.18).

The flux characteristic of the field is not linear to the increase in speed in the field weakening mode. Every field has a characteristic of its own within certain limits. This characteristic can be emulated by means of the parameters Field Cur 40 % (4.07), Field Cur 70% (4.08) and Field Cur 90% (4.09). The characteristic can be determined automatically by means of a service procedure in the parameter Contr Service (7.02). In the case of manual parameterization, make sure that the parameter values are plausible i.e. the value in the parameter Field Cur 40 % (4.07) must be set to a value smaller than the value in Field Cur 70% (4.08), its value in turn must be smaller than the value in Field Cur 90% (4.09). Otherwise, the warning Par Setting Conflict (A16) will be generated.