XFC500 Variable Frequency Drive Model Selection and Motor Instructions

XFC500 series low voltage Variable Frequency Drive is a current vector control inverter. With open-loop current vector control function, high reliability design, high cost performance. It can be used for various automatic production equipment, fans, pumps and other general equipment. And has PLC expansion card, I/O communication expansion card and other expansion functions to meet the application needs of different occasions.

For specific parameters, please refer to the product page of XFC500 Low Voltage AC Drive.

Model Selection of XFC500 VFD (Variable Frequency Drive)

VFD Capacity:

When running a special motor, please confirm that the rated current of the motor is not higher than the rated output current of the frequency inverter. Also, when running multiple induction motors in parallel with one inverter, make sure that 1.1 times the total rated current of the motors is less than the rated output current of the frequency inverter.

Emergency Stop:

Although the protection function will act and the output will stop when the frequency inverter fails, the motor cannot be stopped suddenly at this time. Therefore, install a mechanical stop and hold structure on machinery that requires an emergency stop.

Starting Torque:

The starting and acceleration characteristics of the motor driven by the VFD are limited by the overload rated current of the combined inverter. Compared with the starting of general power frequency power supply, the torque characteristic is small. If a larger starting torque is required, please increase the capacity of the VFD by one level or increase the capacity of the motor and VFD at the same time.

Precautions for the use of the motor driven by the VFD

Standard Motor

Insulation withstand voltage

When the input voltage is high (above 440V) or the wiring distance is long, the insulation withstand voltage of the motor must sometimes be considered. For details, please contact the motor manufacturer.

High-speed Operation

If the motor is used at a speed higher than the rated speed of the motor, dynamic balance and poor bearing durability may occur. Please consult the motor manufacturer.

Torque Characteristics

The torque characteristics are different when driving with an frequency inverter and when driving with a commercial power supply, and the load torque characteristics of the connected machine must be checked.

Vibration

The frequency inverter of XFC500 series can choose high carrier modulation mode PWM control (according to different parameters, low carrier modulation mode PWM control can also be selected). When the high carrier modulation PWM control is selected, the vibration of the motor will be reduced, which is basically the same as when the power frequency power supply is driven. However, in the following cases, the vibration will be slightly larger.

• Resonate with the natural frequency of the mechanical system

Caution is required when performing variable-speed operation on machines that used to operate at a constant speed. At this time, it is more effective to install anti-vibration rubber under the motor frame or perform frequency jump control.

Noise

Noise varies depending on the carrier frequency. When running at a high carrier frequency, it is basically the same as when driven by a power frequency power supply, but running above the rated speed will generate larger wind noise.

Special Motor

• Explosion-proof Motor

When driving a voltage-resistant explosion-proof motor, it is necessary to combine the motor and the VFD for explosion-proof detection, and the same is true when driving an existing explosion-proof motor. In addition, since the main body of the frequency inverter is of non-explosion-proof structure, please install it in a safe place.

• Geared Motor

Due to the different lubrication methods and manufacturers, the geared motor has different continuous rotation ranges. Especially with oil lubrication, there is a risk of sintering only at low speeds. In addition, please consult the manufacturer when using it at a high speed of 50Hz or more.

• Pole Changing Motor

The rated current of the pole-changing motor is different from that of the standard motor. Please confirm the maximum current of the motor and select the corresponding VFD. Be sure to switch the number of poles after the motor stops. If switching is performed during rotation, the regenerative overvoltage or overcurrent protection circuit operates, and the motor coasts to a stop.

• Underwater Motor

The rated current of the underwater motor is larger than that of the standard motor, so please be careful when selecting the VFD capacity. In addition, when the wiring distance between the motor and the frequency inverter is long, the maximum torque of the motor will be reduced due to the voltage drop, so please use a thick enough cable for wiring.

• URAS Vibration Motor

The URAS vibration motor is a vibration motor that outputs centrifugal force as vibration force by rotating the weights (unbalanced weights) installed on both shaft ends of the motor rotor. When using the VFD to drive, you must pay attention to the following matters and select the capacity of the frequency inverter. For specific selection methods, please contact our pre-sales technical staff for inquiries.

• URAS vibration motors should be used below the rated frequency.

• Select V/f control as the control mode of the frequency inverter.

• Since the vibration torque (load inertia) is about 10 to 20 times the motor inertia, set the acceleration time to 5 to 15 s.

• Since the torque of the eccentric moment portion (static friction torque when rotating from a standstill) is large, the starting may not be possible due to insufficient torque during starting.

• Motor With Brake

When a VFD is used to drive a motor with a brake, if the brake circuit is directly connected to the output side of the frequency inverter, the brake cannot be opened due to the low voltage at start-up. Use a motor with a brake independent of the brake power supply, and connect the brake power supply to the power supply side of the frequency inverter. In general, when a motor with a brake is used, the noise may become louder in the low speed range.

• Power Transmission Mechanism (reducer, belt, chain, etc.)

When using oil-lubricated gearboxes, transmissions, reducers, etc. in the power transmission system, the oil-lubricating effect will be poor if it is only continuously operated at low speed, so please be careful. In addition, when running at a high speed of 50Hz or more, problems such as noise of the power transmission structure and reduction of strength and life due to centrifugal force will occur, so please pay sufficient attention.