I'm changing out smoke detectors with about the same types but of different brand. the wiring has to be changed to accommodate them. the green lights are not coming on indicating no AC power to them. what could I have done wrong or do they all need to be wired before they all get power like a series connection or something like that ?

jahnboyblu, February 2014

Why would there be 115 on a DC system??
I assume you have a DSC panel.

And these work backwards to normal detectors.

Alarm, February 2014