Process for determining the phase sequence in a three-phase network (rotary current network)

Process for determining the phase sequence in a three-phase network, in which the phase relationship of the voltage profiles on the three-phase lines of the three-phase network are compared and evaluated, characterized by the following process steps:

• contacting a first phase line with a first test probe and a second phase line with a second test probe of a measurement unit;
• acquiring recurring voltage amplitude points of the voltage present between the two test probes and starting a time window generator at one of these voltage amplitude points, with time windows being generated according to the spacing of the recurring voltage amplitude points;
• removing the first or second test probe from the previously-contacted phase line and contacting this test probe with the third phase line;
• determining inside one or more of the time windows prescribed by the time window generator whether the phase position of the voltage on that phase line which is contacted during both the first and the third steps leads or lags;
• and
• activating a display unit for a clockwise rotating field if the phase voltage on the third line lags and a display for a counterclockwise rotating field if the phase voltage leads.