The 4+n system allows the installation of an intercom with 4 common wires in the riser, where n is the number of wires necessary to control the incoming door calls. In addition, the 4+n system allows the use of intercoms with traditional door call (using a 12 V AC buzzer) or with electronic door call (in this case the call tone is emitted directly via the intercom loudspeaker).Product features:Power supply unit Replacement power supply unit for Grothe 4+n intercoms (e.g. NG229, NG329 or NG399) Technical data:Compatible with system 4+nfor DIN rail mounting Width: 3 sub-units (54mm) Installation note:Note:
