SEFRAM MW9520 Manuel D'utilisation page 51

(b) Locating and tracing lines and outlets:
The circuit must not be live when it is detected,
connect the "+" (red) terminal of MW9520-E to
the phase and the other "COM" (black) terminal
to the protection earth wire. If the cable supplied
by the signals from the transmitter is near other
conductors that are parallel to it (example:
cable tray, channel, etc.) or is interlaced with or
crosses them, the signal may then propagate in
these cables and create spurious circuits then
be detected.
(2) Two-pole application:
(a) The live line connection:
Connect the "+" (red) terminal of MW9520-E
to the phase line of the mains, and connect
the "COM" (black) terminal to the neutral line
of the mains. In this case, the MW9520-E can
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