2N Lift emergency phone 2N LiftNet - Manual, 1446 v1.8.3 - Manual (Page 43)

Lift Cabin Audio Unit
– Compact
2.3
43
Inversion Voltage Control
The figure to the right shows a configuration where voltage is present and activation is
caused by non-presence of voltage.
Bus Connection
The connection polarity is arbitrary.
Warning
 Connection to different, e.g. higher-voltage, cables leads to damage or
destruction of the audio unit.
Caution
 Avoid the audio unit address duplicity.
Figure 2.17 Inversion Voltage Control