Patent ID: 6777830
Filing Date: 2004-08-17
Classification: H02H

Abstract:
A system for reliable prevention of unexpected start-up of a machine, characterized byat least one disconnect switch (DS) which is disposed at the site of the machine (M) at which, the output of the power supply unit (16) is actively confirmed to be power free, and where the verification message is permitted to be displayed only at each disconnect switch (DS) which issues a disconnect signal, if the machine power is switched off and if the output of the power supply unit is actively confirmed to be power free, the machine power is switched off, a power supply unit (PB) connected between the main switch (10) of the main circuit and the machine (M) where the main switch (10) is at the input of the power supply unit (14) and the output of the power supply unit (16) is connected to the machine (M), which power unit (PB) maintains the supply of the power to the machine, operated through (28) the power connections apparatus interrupted if at least one disconnect switch (DS) issues a disconnect signal where the power monitoring apparatus (20) checks the power output (16) of the power supply unit (PB) for a power-free status and which power supply unit permits a restart of the machine (M) if and only if none of disconnect switches (DS) is issuing a disconnect signal, a control unit (CB) with a predetermined number of inputs for disconnect switches (DS) or for a collection and distribution unit (MB), which reports the presence of a disconnect signal at one of its inputs to the power supply unit (PB) and receives the status of the power monitoring apparatus (20) of the power supply unit (PB) and, when the power-free status is reported, issues a verification message to the disconnect switch (DS) which has supplied the disconnect signal; and, if the number of disconnect switches (DS) is larger than the number of inputs of the control unit (CB), at least one collection and distribution unit (MB) having a predetermined number of inputs for disconnect switches (DS) or for a further collection and distribution unit (MB), wherein a disconnect signal is issued at its output when a disconnect signal is supplied at least at one input.