18-12-2014, 03:38 PM
The OPEN contacts on the mhouse control board are "dry contacts", meaning you (or your intercom) should not feed voltage to them or you may damage the board. If your intercom outputs voltage (probably 12 VDC), then you have to install a matching change over relay (the NO and COM contacts of your intercom will be connected to the relay coil and the START contacts will be connected to the Normally Open output of the change over relay).
Using a multimeter to check if the intercom outputs some voltage and if the NO/NC markings are what you expect is a good idea.
Using a multimeter to check if the intercom outputs some voltage and if the NO/NC markings are what you expect is a good idea.