i confirmed that there are more than 4 wires. not sure why i assumed only 4. thanks
as far as i can figure out here is how the 6 FDs are hooked up to the current DSC panel
diagram (sorry for simplicity)
1) why would they have wired it this way?
2) earlier it was mentioned this was dangerous. why?
3) if i wanted to connect these 6 4-wire FD to the ELK M1 - each to a separate zone not Z16, could I?
and if i should not why is that?
4) if i replace all 4 of them should i use 2 wires
how do you all feel about the i3 2WT-B?
any others you recommend if i have to replace all 6 of them for them to work with ELK?
5) the wiring in the JB is quite RIDGID
any idea what kind of wire that is? it only bends with force and can be shaped.
any idea why it was used?
pics of the wiring
1. They may have wired it this way because by connecting the detectors to individual zones, it makes it easy to tell which one triggered an alarm and to be able to see the zone name/number on the keypad. But that's only helpful for false alarms. In a real fire, you want to get out as fast as possible, not waste time with the keypad. Properly installed, smoke detectors shouldn't produce many false alarms, and when they do, the detector that triggered the alarm should latch the condition so you can walk through the house and see which one triggered, before resetting them.
2. It's not dangerous to have the detectors wired to individual zones (though there are other reasons you may not want to). What is dangerous is that the EOL resistors are at the panel, and not and the end of the line, at the detectors. Also, since the existing detectors are 4-wire detectors, each one should have a power supervision relay installed at the detector end. If there is a loss of power to the detector for any reason, the relay will trigger an alarm.
3. You could connect the 6 smoke detectors to individual zones on the Elk. It gets very complicated when you want to reset the system after a fire alarm. DEL provided a good explanation in this thread:
4. If you want to re-use the existing wiring, then you should replace the detectors with 2-wire detectors, so you can use the 4-wire cables to construct a proper daisy chain of the smokes.
The i3 2WT-B is a good smoke detector. You might also want to consider the i4 COSMO-2W, which includes a carbon monoxide detector. But it doesn't have a thermal heat detector like the 2WT-B. In most rooms, you probably don't need the heat detector. The i4 series is compatible with the i3 series, so you can have a mix of the two models.
5. The smoke detector cables look like they are 18 gauge, which they should be. It's stiffer wire than the 22 gauge used for door and window contacts.