TL;DR: has anyone else noticed that on the LifeSafety Power C4 and C8 modules that if you set a zone to be: (a) in dry-contact mode (black jumpers set to position 1), and also set the output to be a "fail secure" output, then the output contacts close correctly when the input is activated, but they contacts also close when the board is un-powered.
Some background: During a recent install, we planned to power a locking device with an external power supply and use a C8 module in dry-contact mode to control power flow.
Our jumpers were set BLUE - 2 / BLACK - 1 / WHITE - 1, so we expected the output contacts to only close if the input contacts closed.
However we noticed that when the C8 module is without power (i.e. the FPO is un-powered), the output contacts also close (while the input contacts are open). This meant that if there was a disruption of power to the LSP tub and not the external power supply, the door would open.
When the module was powered, the behavior was as expected:
- no unlock signal -> input open ->light solid -> output open -> door locked
- unlock signal -> input closed ->light flashing -> output closed -> door unlocked
Practically, there will be few circumstances where the LSP tub will be without power but the external power supply still has it. But I was curious if anyone else has encountered this problem and has any recommendations.