Patent ID: 11909353
Assignee: KEHUA HENGSHENG CO., LTD.
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  G  Y | IPC G  H

Claim 1:
2. The ground-fault detecting device of claim 1, wherein the controller is arranged to obtain the first sampled voltage when a first switch is closed and a second switch and a third switch are opened, to compare the first sampled voltage to a first predetermined threshold voltage, and to generate the alarm signal when the first sampled voltage is smaller than the first predetermined threshold voltage;
the controller is further arranged to obtain the second sampled voltage when the second switch is closed and the first switch and the third switch are opened, to compare the second sampled voltage to a second predetermined threshold voltage, and to generate the alarm signal when the second sampled voltage is smaller than the second predetermined threshold voltage; and
the controller is further arranged to obtain the third sampled voltage when the third switch is closed and the first switch and the second switch are opened, to compare the third sampled voltage to a third predetermined threshold voltage, and to generate the alarm signal when the third sampled voltage is smaller than the third predetermined threshold voltage;
wherein the first sampled voltage, the second sampled voltage, and the third sampled voltage are voltage differences between the first terminal and the second terminal of the grounding resistor respectively.