Hitachi SJ700-2 instruction manual Dynamic braking BRD function, Cooling-fan operation setting

Chapter 4 Explanation of Functions

4.2.37 Dynamic braking (BRD) function

The dynamic braking (BRD) function is provided in the SJ700-220LFF/HFF and other models that have the built-in BRD circuit. With this function, the energy regenerated by the motor is consumed by an external resistor (i.e., the energy is converted to heat). You can effectively use this function in your system, for example, to operate the motor as a generator by rapidly decelerating the motor.

To use this function, make the following settings:

Related code

b090: Dynamic braking usage ratio

b095: Dynamic braking control

b096: Dynamic braking activation level

Item	Function code	Data or range of data			Description
		0.0	Disabling the BRD operation
			Setting of the dynamic braking usage ratio in units
			of 0.1%
			The inverter will trip when the set rate is exceeded.
				t1	t2		t3
Dynamic braking	b090 (*2)
				ON	ON		ON
usage ratio		0.1 to 100.0 (%)
			BRD		100 seconds
			operation
			Usage rate (%) =		(t1+t2+t3)	⋅ 100
					100 seconds
		00	Disabling the BRD operation
			Enabling the BRD operation while the motor is
Dynamic braking	b095	01	running
			Disabling the BRD operation while the motor is
control
			stopped
		02	Enabling the BRD operation regardless of whether
			the motor is running
Dynamic braking	b096	330 to 380 (V) (*1)	Level setting for 200 V class models
activation level		660 to 760 (V) (*1)	Level setting for 400 V class models

*1 The set dynamic braking activation level specifies the DC output voltage of the inverter's internal converter.

*2 Please refer P2-22 for minimum resistance of connectable resistor and BRD ratio (2.2.5).

4.2.38 Cooling-fan operation setting

The cooling-fan operation setting function allows you to specify the operation mode of the inverter's internal cooling fan. The cooling fan can be operated on a constant basis or only while the inverter is driving the motor.

Related code

b092: Cooling fan control

Item	Function code	Data or range of data	Description
		00	Specifying that the fan operates on a constant basis
Cooling fan			Specifying that the fan operates only while the
	b092		inverter is driving the motor.
control		01	Note that the fan operates for 5 minutes after the
			inverter power is turned on and after the inverter is
			stopped.

Note: The cooling fan stops automatically when instantaneous power failure occurs or the inverter power is shut off and resume the operation after power recovered.

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