VFC 1 / 2 & DC BRAKE and V/f DC BRAKING

The DC braking function allows the asynchronous motor to be decelerated using a direct current injection. The motor can be braked without a braking resistor using the inverter.

A constant current with a rotating field frequency of 5 Hz is supplied during the braking process. The braking torque = 0 at standstill. At a low speed, the braking torque is high, at higher speeds, the braking torque decreases. The braking time and consequently the duration of the braking current depends on the load connected to the motor. DC braking is stopped once the rotating field frequency of the motor reaches 5 Hz and the motor is stopped using the rapid stop ramp. Current is impressed with rated motor current according to the startup function. In all cases, the inverter limits the current to max. 125% I_N. For controlling the brake, see the braking function.

NOTICE

No guided stop.

Can cause damage to the system.

INFORMATION

• The braking procedure is not interrupted if the digital input "Enable" receives a "1" signal again during the braking phase. DC braking is completed before the drive is accelerated.
• The drive stops with ramp t11/t21 or t12/t22 if a binary input is programmed to the function "CW/Stop (CCW/Stop)" in "VFC 1/2 & DC BRAK." operating mode and "CW/Stop (CCW/Stop)" receives a "0" signal. The stop is continued and no DC braking initiated if the digital input "Enable" is switched from "1" to "0" during the ramp time.To start DC braking, you must first switch "Enable" from "1" to "0". This must happen at least 10 ms before switching "CW/Stop (CCW/Stop)" from "1" to "0".