Earth (ground) fault detection at start
Select whether to enable/disable earth (ground) fault detection at start. When enabled, earth
(ground) fault detection is performed immediately after a start signal input to the inverter.
● If a ground fault is detected at start while Pr. 249 = "1", the output-side earth (ground) fault
overcurrent (E.GF) is displayed and the outputs are shut off. (Refer to page 6-23.)
● The Pr. 249 setting is enabled during V/F control and Advanced magnetic flux vector control.
● When the Pr. 72 "PWM frequency selection" setting is high, enable the ground fault detection at
Because of the detection performed at start, the output is delayed by approximately 20 ms at
Use Pr. 249 to enable/disable ground fault detection at operation start. Ground faults are detected
always during operation regardless of the Pr. 249 setting.
If a smaller-capacity motor is used with the FR-F820-00250(5.5K) or higher and FR-F840-
00126(5.5K) or higher, ground fault protection may be insufficient.
Varying the activation level of the undervoltage protective function
If the undervoltage protection (E.UVT) activates due to unstable voltage in the power supply, the un-
dervoltage level (DC bus voltage value) can be changed (only available for 400 V class).
Do not use this function when switching to an external battery, since the inrush current when
power is restored increases, as the undervoltage level is decreased.
The Pr. 598 settings are only valid for 400 V class inverters.
The Pr. 598 setting is invalid during PM motor control. The Pr. 598 setting is also invalid during PM
motor control for the first or second functions.
Earth (ground) fault
detection at start
Without the earth (ground) fault detection at start
With the earth (ground) fault detection at start
Setting range Description
350 to 430 V DC Set the DC voltage value at which E.UVT occurs.
E.UVT occurs at 430 V DC
(H) Protective function parameter
5 - 161