| 摘要 |
<p>The invention relates to a method for determining a phase failure in an electrical device (1) for driving or monitoring a three-phase AC motor (2), wherein the electrical device (1) comprises a first, a second and a third line (6,7,8). In order to detect a phase failure in a line (8) in the three-phase electrical device (1), in particular in a soft starter (1), the phase failure in the third line (8) is determined by analysing the first and second lines (6,7), wherein the analysis comprises the following steps: determining a value which characterizes a phase shift between a current in the first and second lines (6,7), and outputting a signal if the value which has been determined is in a range of values which characterizes a phase failure in the third line (8).</p> |
