# FAQ

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- FAQ > Drive Products > Inverters-FREQROL > Inverter current characteristics

## FAQ

## Inverter current characteristics

When a general-purpose or vector inverter is used at a constant-torque, the motor current and torque are proportional during operation at 60 Hz or lower.

Over 60 Hz means variable-torque. How the relationship between torque and current will be? (I want to know motor current values during operation over 60 Hz.)Also, describe the vector inverter and general-purpose inverter in details.

Over 60 Hz means variable-torque. How the relationship between torque and current will be? (I want to know motor current values during operation over 60 Hz.)Also, describe the vector inverter and general-purpose inverter in details.

- Category :

## Answer

In general, relationship between T (torque), K (constant), V (voltage), I (current), and F (frequency) is expressed as "T = K × (V/F) × I".

Since (V/F) is constant at up to 60 Hz, the current and torque are proportional.

After exceeding 60 Hz, V (voltage) is now constant and a constant output range is entered. To keep torque constant, it is necessary to increase the current in accordance with F (frequency).

In other words, when 60 Hz is exceeded, torque decreases in inverse proportion to the frequency. (For example, when the frequency increases from 60 Hz to 80 Hz, current must be increased for 80/60 to keep torque constant.)

Operation of vector inverter motor is almost same as the general-purpose motor.

Since (V/F) is constant at up to 60 Hz, the current and torque are proportional.

After exceeding 60 Hz, V (voltage) is now constant and a constant output range is entered. To keep torque constant, it is necessary to increase the current in accordance with F (frequency).

In other words, when 60 Hz is exceeded, torque decreases in inverse proportion to the frequency. (For example, when the frequency increases from 60 Hz to 80 Hz, current must be increased for 80/60 to keep torque constant.)

Operation of vector inverter motor is almost same as the general-purpose motor.

- Product Name
- Inverter, magnet motor drive

- Product Category
- Inverter

- Series
- FR-V200