Hitachi SJ700D-004L, Instruction Manual

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Chapter 4 Explanation of Functions
4-22
(3) Internal DC braking (A051: 01)
You can apply DC braking to the motor even without entering braking signals via the DB terminal when the inverter
starts and stops. To use the internal DC braking function, specify "01" for the DC braking enable (A051).
Use function "A057" to set the DC braking force for starting, and use function "A058" to specify the DC braking time for
starting, regardless of the braking mode selection (edge or level mode). (See Example 4-a and 4-b.)
Set the braking force for periods other than starting by using the DC braking force setting (A054).
Set the output frequency at which to start DC braking by using the DC braking frequency setting (A052).
When you set the DC braking wait time (A053), the inverter output will be shut off when the output frequency reaches
the setting of "A052" after the operation command (FW signal) is turned off, and the motor will run freely for the delay
time set by "A053". DC braking will be started after the delay (A053).
The internal DC braking operation to be performed when the operation command is switched from the stop command
to the start command varies depending on the braking mode (edge or level mode).
Edge mode: The DC braking time setting (A055) is given priority over operation commands, and the inverter
performs DC braking according to the setting of "A055". When the output frequency reaches the
setting of "A052" the inverter performs DC braking for the time set for "A055". Even if the stop
command is input during DC braking, DC braking continues until the time set for "A055" elapses. (See
Example 5-a and 6-a.)
Level mode: Operation commands are given priority over the DC braking time setting. The inverter follows
operation commands, regardless of the DC braking time setting (A055). If the start command is input
during DC braking, the inverter starts the normal motor operation, regardless of the DC braking time
setting (A055). (See Example 5-b and 6-b.)
(a) Edge mode (b) Level mode
i) (Example 4-a) when the start command is input: i) (Example 4-b) when the start command is input:
ii) (Example 5-a) when the stop command is input: ii) (Example 5-b) when the stop command is input:
ii) (Example 6-a) when the stop command is input: ii) (Example 6-b) when the stop command is input:
FW
Output
frequency
FW
Output
frequency
FW
Output
frequency
FW
Output
frequency
FW
Output
frequency
FW
Output
frequency
A058
DC braking
A058
DC braking
A053
Free running
A055
A052
DC braking
DC braking
A053 A055
A052
Free running
A052
A055
DC braking
A052
A055
DC braking