Device for detecting an insulation fault between a source of DC voltage and an electrical ground, comprising: - a bridge configuration comprising: - first to fourth nodes (461,462,463,464), the first and third nodes being intended to be connected to the terminals of a high-power source of DC voltage; - a first branch connecting the first and second nodes, and comprising a first controlled switch configured for selectively interrupting the conduction in the first branch; - a second branch connecting the second and third nodes, and comprising a second controlled switch configured for selectively interrupting the conduction in the second branch; - a third branch connecting the first and fourth nodes, and comprising a third controlled switch configured for selectively interrupting the conduction in the third branch; - a fourth branch connecting the third and fourth nodes and comprising a fourth controlled switch configured for selectively interrupting the conduction in the fourth branch; - a fifth branch connecting the second and fourth nodes, characterized in that: - the fifth branch comprising a capacitor connected between the second and fourth nodes, an electrical ground being connected to the fifth branch between said capacitor and the fourth node; - a control circuit controlling said switches in such a manner as to carry out the successive steps for: a) maintaining the first and fourth switches closed and the second and third switches open, so as to charge said capacitor; b) maintaining the second switch closed and the first, third and fourth switches open; - a first measurement circuit measuring the current flowing through said capacitor; - an analyzer circuit determining the amplitude of an insulation fault as a function of a current measured by the measurement circuit during the step b). - a bridge configuration comprising: - first to fourth nodes (461,462,463,464), the first and third nodes being intended to be connected to the terminals of a high-power source of DC voltage; - a first branch connecting the first and second nodes, and comprising a first controlled switch configured for selectively interrupting the conduction in the first branch; - a second branch connecting the second and third nodes, and comprising a second controlled switch configured for selectively interrupting the conduction in the second branch; - a third branch connecting the first and fourth nodes, and comprising a third controlled switch configured for selectively interrupting the conduction in the third branch; - a fourth branch connecting the third and fourth nodes and comprising a fourth controlled switch configured for selectively interrupting the conduction in the fourth branch; - a fifth branch connecting the second and fourth nodes, - first to fourth nodes (461,462,463,464), the first and third nodes being intended to be connected to the terminals of a high-power source of DC voltage; - a first branch connecting the first and second nodes, and comprising a first controlled switch configured for selectively interrupting the conduction in the first branch; - a second branch connecting the second and third nodes, and comprising a second controlled switch configured for selectively interrupting the conduction in the second branch; - a third branch connecting the first and fourth nodes, and comprising a third controlled switch configured for selectively interrupting the conduction in the third branch; - a fourth branch connecting the third and fourth nodes and comprising a fourth controlled switch configured for selectively interrupting the conduction in the fourth branch; - a fifth branch connecting the second and fourth nodes, - the fifth branch comprising a capacitor connected between the second and fourth nodes, an electrical ground being connected to the fifth branch between said capacitor and the fourth node; - a control circuit controlling said switches in such a manner as to carry out the successive steps for: a) maintaining the first and fourth switches closed and the second and third switches open, so as to charge said capacitor; b) maintaining the second switch closed and the first, third and fourth switches open; a) maintaining the first and fourth switches closed and the second and third switches open, so as to charge said capacitor; b) maintaining the second switch closed and the first, third and fourth switches open; - a first measurement circuit measuring the current flowing through said capacitor; - an analyzer circuit determining the amplitude of an insulation fault as a function of a current measured by the measurement circuit during the step b).