| 摘要 |
<p>A definite switching-off of drive equipment for elevators is accomplished with a control at an input side external of a frequency changer power unit that ascertains the presence or the absence of monitoring signals which are derived from the mains voltage at the input of the frequency changer power unit. Upon ascertaining the presence of one or more such signals when the drive is at standstill, the input side control interrupts the energy flow to the frequency changer power unit by generating a switching-off signal to a switching device to disconnect the mains voltage.</p> |
