Security panel is GE NX-8E
Sensors are System Sensor model CO1224TR

I've been doing automation for 30+ years but always partnered with a security contractor so I have minimal experience. But this is my house and I want to do it myself. Panel is up and running and working fine for security zones. Now I neeed to install smokes sensors and carbon sensors.

1. Carbon sensor nstructions state to connect to a non-resettable power supply. why? CO sensors don't need resetting in the event of trouble like smoke sensors?

2. I have 2 CO sensors to install, one on each floor near bedrooms. I have 2 each 4 cond wires home run run to each location from the panel. I can wire them in a loop and am contemplating this to save zones. But I do have enough zone real estate on the panel to give them each their own zone. What do most security installers recommend?

3. I have not looked it up on my panel yet, but do most panels have a zone setting for CO sensors? Like they do for smoke sensors? So they sound the alarm if tripped, regardless of the system being armed or disarmed?

4. There is a trouble relay on the sensors that is Normally Closed if power to the sensor is present. Zone wiring goes through these 2 trouble relay terminals. I'm guessing the trouble relay goes open if power is lost? Maybe this the answer to question #1?

5. In real life, if a sensor (that is wired and functioning correctly) detects CO and trips, you would simply reset the alarm with the code (most panels) and it would shut up? Assuming the CO issue has been cleared?

6. How do most security people test their CO sensors after installation is complete? Is there a spray can similar to testing smoke sensors?

This is not going to be a UL listed installation

I can put the power for the sensors on a good UPS which I think is code. Building permit is 2011 code, and local county jurisdiction indicates security panel CO sensors (and smoke) are approved for passing inspection.

Well I have the answer to questions #6.

The sensor has a test mode and one uses a can of spray.

It appears that I would not really need to connect this to the security panel, since the sensors have their own internal sounding/ alert. As long as they are connected to a battery backed up power source.

And they would need to be looped so that if one goes into trouble, they both sound an alarm (if not connected to a panel)

Connect the sensors in series most 12V smoke and CO sensors have an interlock connection to trigger all devices connected to them and you would run them in series with each other to obtain this.

I would use the security system 12V AUX output to power them (same with the smoke detectors). You already have a battery backup on your security system so why add more than needed?

You can program the zone to be 24hr Gas which triggers the alarm no matter the state of the security system. You also want to change the siren to be pulse not steady (same with the smokes).