Hitachi SJ700-2 instruction manual Phase loss power input protection, Disabling the protection

Chapter 4 Explanation of Functions

(3)Restarting methods

-Restart with matching frequency

The inverter detects the frequency and rotation direction based on the residual voltage in the motor, and then restarts the motor based on the detected frequency.

-Restart with input frequency

The inverter starts the output with the frequency specified for the start frequency selection (b030), searches for the point where the frequency and voltage are balanced while keeping the current at the restart current level (b028), and then restarts the motor.

If the inverter trips when it restarts the motor in this way, reduce the setting of "b028".

-After the inverter output has been shut off, the digital operator continues to display until the inverter restarts the motor operation.

FW

FRS

b028

Output current

Deceleration according to the setting of "b029"

Inverter output
frequency	Frequency selected as the
	setting of "b030"

Motor speed

b003

4.2.28 Phase loss power input protection

Related code

The phase loss power input protection function gives a warning when phase loss power is input to the inverter.

b006: Phase loss detection enable

Item	Function code	Data	Description
Phase loss detection	b006	00	Disabling the protection
enable		01	Enabling the protection

An phase loss power input may cause the following conditions, resulting in an inverter failure:

(1)The ripple current increases in the main capacitor, and the capacitor life will be shortened significantly.

(2)When the inverter is connected to a load, the internal converter or thyristor of the inverter may be damaged.

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