| 摘要 |
<P>PROBLEM TO BE SOLVED: To avoid generation of large leakage current even when connecting a measuring terminal to an active power cable by mistake. <P>SOLUTION: A ground resistance meter has a protective resistance 7 arranged on a current path A of measurement current I1 including a current supply part 4 and each of measuring terminals 2 and 3 for restricting the value of the measurement current flowing into the current path A upon connecting the measuring terminal 2 to an active power cable 33 to be equal to or less than a prescribed current value, a switch 8 which is normally in a OFF state and short-circuits the protective resistance 7 in an ON state, and a first detection part 16 for detecting a connection of the measuring terminal 2 to a neutral cable 32 when the switch 8 is in an ON state based on a between-terminal voltage V1. A processing part 19 executes a resistance calculation processing by putting the switch 8 in an ON state when the first detection part 16 detects a connection of the measuring terminal 2 to the neutral cable 32. <P>COPYRIGHT: (C)2012,JPO&INPIT |
