| 摘要 |
The invention relates to a method and a zero-speed monitor for monitoring a three-phase machine (1) which has been disconnected from the electrical mains and is running down, the voltage generated by the three-phase machine (1) being supplied to a zero-speed monitor and release lines (F1, ..., F4) for safety-relevant devices being disconnected when it is confirmed that the three-phase machine (1) is stationary, one phase of the generated voltage being checked respectively in two channels for zero crossings and, if a zero crossing occurs, a signal being produced which, after DC-decoupling, is used to control the operation of mutually interlocked disconnection relays of the two channels via these releasing disconnection signals.
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