System Sensor 4WT-B Four Wire Smoke Detector With Built-In Heat Sensor

I am replacing four 2412 System Sensors. Is the 4WT-B 4-wire, photoelectric smoke detector a good replacement? Second, The wiring is different from my present sensors, in that the 2412s are wired in parallel for the idc and power terminals and only a resistor at eol. Should I follow the 4WT-B schematic and also install a relay? Thanks. Tom

There are multiple 2412 models out there, but the standard 2412 would not have a heat sensor, so the 4W-B would be the direct replacement unless you want to have the heat protection of the 4WT-B model. As for wiring, it should be pretty similar except the 4W models use an incoming and outgoing positive terminal for the power wire, but its pretty straightforward if you follow the manual. All 4-wire smoke chains should have an end of line relay to supervise power, if your 2412s do not, then I would add one. 

can I replace my DSC 410BST with the System Sensor 4WT-B 4-wire, photoelectric i3 smoke detector with a 135 Degree fixed thermal sensor

Yes, the 4W smokes are a viable replacement for 410 models. If I recall the terminal style should be very similar as well making installation pretty simple.

Is the 4WB-T suitable for replacing a 2812TH? Thanks.

Ther terminals between the 2 sensors will be a bit different, but yes the 4WT-B is a smoke and heat detector just like the 2812TH is. It should work fine.

I am using this in a remodel job as a single smoke-heat detector. Do I need to use an EOL relay if there is only one detector without integral siren, or can I just use 2 EOL resistors?

No system Im aware of has the capability to monitor the power wires on 4-wire smokes, and if you used a second resistor Im not sure where you could put it that would provide that supervision. You dont technically HAVE to use the EOL relay at all, but if you want to ensure the smoke is always powered, you will need it.

Is this sensor completely compatible with my DSC HS2032 Neo control board?

Yes, the 4W smokes work with all standard hardwired alarm systems.

can this be installed in attic with temps in the 100-110 range ?

No, photoelectric smokes such as the 2W or 4W series should not be installed in an attic because of likely falsing due to the dusty enviornment likely there., There are only for finished interior spaces. A heat detector is the proper sensor for an attic. See here:
https://www.alarmsystemstore.com/collections/heat-detectors

replacing System sensor 2112/24T , will 4WT-B be current replacement ?

Yes the 4W series is the correct replacement for the System Sensor 2112 series.

I need a fire/Smoke detector to replace the one with my Radio shack Safe House security system, it calls for a 4 wire Smoke Detector supervised by a U. L. end of line module. Will any of these work for me?

I am unfamiliar with the Radio Shack system as it's quite old, but if it's specs call for a 4 wire low voltage smoke with a normally open alarm circuit, yes these will work.

What is the difference between a 4wt-b and a 4wtA-b?

The A means it has an audible sounder built into the smoke detector. That's the only difference. No sounder in this one and it relies only on the system sirens.