• TimeSquirrel
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      1 year ago

      It depends on the system. I install access control stuff. We use unpowered pneumatic timer buttons to open the doors in an emergency (they have to keep the door open for a certain number of seconds when pushed once), and they are indeed big and red with white text on them, shaped like a mushroom you can just slap with your hand. Often the fire alarm is also tied into the access control, so if the fire alarm is going off, the door will be open anyway. There’s a relay from the fire alarm that triggers a special input on the access control panel.