System Sensor 2W-B

2-Wire Smoke Detector

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The System Sensor 2W-B is a 2-wire smoke detector and a member of System Sensor’s i3 Series of photoelectric smoke detectors. The 2W-B sm...
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The System Sensor 2W-B is a 2-wire smoke detector and a member of System Sensor’s i3 Series of photoelectric smoke detectors. The 2W-B smoke detector works with most Honeywell alarm control panels including the VISTA-20P and VISTA-21iP as System Sensor is a subsidiary of Honeywell. However, you can also use the 2W-B smoke detector with other alarm control panels, but you should verify compatibility with the manufacturer of the alarm control panel first.

All System Sensor i3 Series smoke detectors are designed for easy installation, advanced detection and fast inspection. The 2W-B smoke detector consists of a mounting base that can be mounted on a single gang box, a three and a half or four inch octagonal box or a four inch square box with a plaster ring. For convenience, the 2W-B mounting base can also be directly mounted to the ceiling using drywall fasteners. Once the mounting base is installed, the 2W-B smoke detector attaches to the base by simply inserting the head and turning it clockwise until it locks in place. When performing maintenance on your smoke detector, simply turn the 2W-B head counter clockwise to remove it from the base. You can also remove the detector cover and the sensing chamber for convenient smoke detector cleaning.

The System Sensor 2W-B smoke detector has a sensing chamber that that will become dirty with dust over time. With less intelligent smoke detectors, a dirty photoelectric chamber will results in false alarms. The i3 Series 2W-B uses drift compensation technology and smoothing algorithms which prevent the smoke detector from becoming too sensitive as dust accumulates. This feature ensures that your security system will not experience nuisance false alarms.

While the drift compensation and smoothing algorithms make the 2W-B more advanced than other conventional smoke detectors, it will eventually need to be cleaned. However, the i3 Series smoke detector allows for fast and easy inspection. There is a red and green LED on the head of the 2W-B smoke detector. When the smoke detector is normal the green LED will blink every five seconds. When the sensing chamber gets too dirty and the 2W-B is no longer calibrated to the proper sensitivity, the smoke detector will alert you with a red LED that blinks every five seconds so that you can perform the necessary maintenance. Whenever an alarm is detected by the System Sensor 2W-B, the smoke detector will show a solid red LED.

When using the System Sensor 2W-B two wire smoke detector with a VISTA-20P or VISTA-21iP alarm control panel, you should wire the smoke detector to zone one. You can use up to sixteen 2W-B smoke detectors on the zone one fire loop. Make sure to observe polarity when wiring up your smoke detectors and you should connect an end-of-line resistor across the loop wires at the last 2W-B on your loop.

Read here to learn the difference between smoke detectors and smoke alarms. Photoelectric smoke detectors work with an alarm system, and when properly maintained and tested, can last for an indefinite period and do not automatically require replacement after a certain period of time like smoke alarms and CO detectors do.

Brand: System Sensor

System connected smoke detectors may be successfully deployed for many years, and no scheduled end of life replacement is prescribed. Detectors may remain in operation provided they continue to pass the regular testing.
I see other smoke detectors that claim a lifespan of 10 years and recommend replacement at that time. Do these detectors have a similar lifespan?
Will these cover up a low voltage mudring? Or should i plan on just running the wire directly out of the drywall?
I was planning on installing about 11 of these on a vista 21ip panel, what is the power draw I should account for when planning against the 650 mA allowance for the panel?
The cable companies often use a special adapter to monitor a VISTA-20P system as explained at Do you see that white unit anywhere in or near your 20P alarm panel?
Thank you for the response @disqus_YuNiL6S1Rn:disqus. I have since replaced the battery, which has resolved the smoke error. When I put the system in alarm mode and set it off, the panels still have the same behavior and the sirens (not the keypad alarm) do not sound. I still get the "shorted out keypad". I am wondering if there is too much power connected to the panel for the sirens to sound. This system was used with Cox before, so no telling what all they did to it. haha
Hi Dustin, It sounds like you may be experiencing a low battery issue possibly. To test this please remove AC power and set the panel into alarm mode to see if the battery will support the system and report back. Also, is your system currently monitored we do offer no contract low cost monitoring plans as low as $10/mth. Please send an email to referring to this inquiry to better assist you with your 20P
Hello, I have a vista 20P (came with the house I bought) that has (4) 2 wire smokes wired in. After some recent electrical work (new AC unit in the attic) the vista 20p shows fire trouble, and occasionally sets off the alarm. When the alarm goes off, both keypads seem like they short out for a second (the display panel goes blank the ready and arm lights flash, and it makes a weird beeping noise) then starts the alarm tone at the keypads only. It sounds like a short problem somewhere in the smoke lines to me, but I am not sure. Any advice/help would be greatly appreciated.
Thanks for your insight and expertise!
Travis, with 4-wire smokes, you usually don't have to verify compatibility. As long as they operate at 12 Volts DC, they should work. It appears that these two models are very similar in their features (neither has a sounder, both operate at 12 or 24 Volts) so this should be a satisfactory replacement.
I have a Vista 6150 15P Control Panel and an old System Sensor 2312/24TB 4 wire Smoke/heat detector. I would like to replace it with similar 4 wire detector like the 4WT-B detector and wanted to check if they are compatible?
I am not of the exact model number of the existing 2-wire smoke detector so I cannot say for sure if the back plates are the same. If they are not just take a photo of the connections and land what is connected to the positive connection the new plates positive and same with the negative. It should be straightforward if you do not need to wire the back plate. I recommend powering down the system and placing your system on test mode if monitored before swapping in the new smoke.
It should connect the same exact way. Leave everything as is at the panel and simply replace the smoke detector itself.
Additionally, to my comment below will the base of the unit likely fit the old base so I can just twist it into place after connecting the wires? I have a DSC alarm system that my current System Sensors are connected to and would I need to do anything special when I replace the old with the new other then reset the system?
I have an old System Sensor 2 wire photoelectric smoke alarm (hardwired) that is about 17 years old and has finally gone out - trying to figure out if this particular unit will work seamlessly as a replacement for my existing alarm - there is a connection to the back of the alarm and wonder if I can just hook up the new alarm the same away the old alarm is connected and have it work?
Unfortunately we do not support fire panels like the 32FB. However zones 1 and 2 can support 16 on each zone. Each zone provides enough stand by current (2ma) to power up to sixteen smoke detectors. Each zone provides only enough alarm current (20ma) to power one smoke in alarmed state. system is the site link for a current list of all UL listed compatible smoke detectors. The 2W-B should work zones 1 and 2 since they are designed for system sensor 2-wire devices.
CAN 2W-B be used on VISTA32FB
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