4-2 Function Mode DC Injection Braking (DB) This function securely stops the motor rotation during deceleration. 4 Functions •Two methods are available for DC injection braking: One is the external method via the multi- function input (external DC injection braking); the other is the internal method performed automatically to stop the motor (internal DC injection braking). •Below are operation types: Edge operation: DB operates during the specified time period from the DB signal input. Level operation: DB operates while a signal is being input. Frequency control mode: DB operates when the frequency reaches the specified level during operation.
•If DC injection braking operates at a high motor speed, an overcurrent trip (E01 to E04) or overload trip (E05) may occur. For internal DC injection braking, the following adjustment may help you avoid such a situation: Lower the DC injection braking frequency (A052). Increase the DC injection braking delay time (A053) For external DC injection braking via the multi-function input, use the external DC injection braking terminal (along with deceleration stop). External DC Injection Braking (A051 = 00) •Allocate 07 (DB) to the desired multi-function input. DC injection braking can be applied by turning on/off the DB terminal, regardless of the DC injection braking selection (A051).
•Set the DC injection braking power in A054. •If the DC injection braking delay time (A053) is set, the Inverter output will be shut off during the specified time period and the motor goes into free-run status. After the set time elapses, DC injection braking starts. •Set the DC injection braking time (A055) via the Digital Operator or the DB terminal while taking into account motor heat generation. Long continuous use of DB may cause the motor to burn out. •Perform each setting according to your system after selecting the level or edge operation in A056. 4-15 Parameter No. Function name Data Default setting Unit A051 DC injection braking selection 00: Disabled 01: Enabled 02:
DB when output frequency 00 ⎯ A052 DC injection braking frequency 0.0 to 60.0 0.5 Hz A053 DC injection braking delay time 0.0 to 5.0 0.0 s A054 DC injection braking power 0. to 100. 50 % A055 DC injection braking time 0.0 to 60.0 0.5 s A056 DC injection braking method selection 00: Edge operation 01: Level operation 01 ⎯ Related functions C001 to C005