You can find the specific wiring diagrams and installation steps in these official and community-sourced documents:
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Keep the intercom wiring at least 30cm away from AC power lines to avoid "humming" or static noise in the audio. You can find the specific wiring diagrams and
: Both the internal handsets and the external door station are designed for surface mounting using provided brackets and screws. Maintenance and Troubleshooting commax dpra01 installation manual link
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