2N Lift emergency phone 2N SingleTalk - Manual, 1514 v6.3.0 - Manual (Page 23)

Mounting
– Universal version
2.3
22
Mounting drawing for version with 40 mm speaker
4 spot-welded M4 screws on the
panel or lift cabin backside (typically
2 mm thick stainless steel sheet)
perforated loudspeaker area
(25% perforation at least)
Two LED holes (optional, backlit
pictograms are preferred, located
outside the panel)
Microphone perforation
Fit the mounting panel in such a way that it cannot vibrate while operation. There may
be no gap between the wall surface and the ST panel, or, if any, it must be sealed
properly to eliminate acoustic short-circuit of the loudspeaker and acoustic coupling
between the loudspeaker and the microphone (see later).
Caution
 Make sure that the microphone hole is sealed properly to sense the lift
cabin sounds only and suppress the noise coming from the shaft or cavity
behind the wall!