Simplex 4098-9770 — a TrueAlarm addressable CO sensor base, standard operation, that adds carbon monoxide sensing to a TrueAlarm sensor location while consuming only one IDNet address.
The base holds an electrolytic carbon monoxide sensing module alongside a TrueAlarm analog sensor head, ordered separately, to form a single multi-sensing assembly on one system address with sub-points layered beneath it. That buys three distinct capabilities. It performs UL 2034 CO alarm detection for life safety. It can perform UL 2075 OSHA-style level monitoring, where a threshold above 30 ppm is programmed at the panel to drive ventilation control. And, with a photoelectric or photo/heat head fitted, it feeds multi-criteria fire analysis: False Alarm Reduction correlates CO and photoelectric data to reject steam, dust, aerosols, tobacco and cooking smoke, while Faster Detection works the other way, so that a head set to a conservative 2.5%/ft can reach an effective sensitivity approaching 0.5%/ft when significant CO is present — useful in museums and electrical equipment rooms where a permanently sensitive setting would be unworkable. The panel stores CO concentration in ppm for viewing, produces a TrueAlarm CO service report, and tracks the cartridge's end of life. The 4098-9770 is the standard version and takes its power from the IDNet channel, so existing TrueAlarm base locations can be upgraded without new wiring.
Specifications
| Device type |
TrueAlarm addressable CO sensor base, standard operation; multi-point device using one IDNet address |
| Communications and sensor supervisory power |
IDNet communications, one address for each base; no separate power required for the standard base |
| Communications connections |
Screw terminals for in/out wiring, 18 to 14 AWG (0.82 mm² to 2.08 mm²) |
| Compatible sensor heads |
4098-9714 photoelectric smoke, 4098-9764 photo/heat multi-sensor, or 4098-9733 heat — one required, ordered separately |
| Compatible control units |
4007ES, 4010ES and 4100ES with software revision 2.01.02 or higher; 4100U with software revision 12.05 or higher |
| UL listed temperature range |
32°F to 100°F (0°C to 38°C) |
| Operating temperature range |
15°F to 122°F (-9°C to 50°C) with the 4098-9714 or 4098-9764; 32°F to 122°F (0°C to 50°C) with the 4098-9733 |
| Humidity range |
15% to 95% RH |
| Air velocity rating |
0 to 1,000 ft/min (0 to 305 m/min) with the 4098-9714 or 4098-9764 |
| Housing color |
Frost white |
| CO sensor service life |
10 year operational lifetime tracked by date code (5 years on 4100U FACUs), with expiration notices at 12 months and 6 months |
| OSHA level monitoring |
CO condition level programmed by concentration at the panel; must be greater than 30 ppm |
| UL 2034 / CSA 6.19-01 response time |
70 ±5 ppm: 60 to 240 minutes · 150 ±5 ppm: 10 to 50 minutes · 400 ±10 ppm: 4 to 15 minutes |
| UL 2034 / CSA 6.19-01 false alarm resistance |
30 ±3 ppm: no alarm for 30 days · 70 ±5 ppm: no alarm for 60 minutes |
| CO level tracking |
Levels above 40 ppm are time-integrated at the panel to determine the alarm point; levels below 40 ppm are not tracked |
| Remote LED alarm indicator |
1 mA typical, supplied from communications, no impact to alarm current; color coded 18 AWG leads |
| Mounting, without relay |
4 in. octagonal or 4 in. square box, 1-1/2 in. deep; or single gang, 2 in. deep |
| Mounting, with relay |
4 in. octagonal or 4 in. square box, 1-1/2 in. deep, with a 1-1/2 in. extension ring |
| Listings |
Listed to UL 268 and UL 2075, allowing systems to be listed to UL 2034; listed by ULC to CSA 6.19-01; FM approved; CSFM Listing 7300-0026:330 |
Installation notes
-
Air velocity is far lower than a standard base. The CO sensor base is rated 0 to 1,000 ft/min with a photoelectric or multi-sensor head, against 0 to 4,000 ft/min for a standard TrueAlarm base. High-airflow locations that suit an ordinary sensor may not suit this one.
-
Panel software revisions are mandatory: 4007ES, 4010ES and 4100ES need revision 2.01.02 or higher; the 4100U needs revision 12.05 or higher.
-
Point allocation differs by panel: 4007ES, 4010ES and 4100ES require one point per CO sensor base. The 4100U requires three points per base with the multi-sensor and two points with the other sensors. Up to seven points can be made public to a connected fire alarm network.
-
The CO element expires and must be replaced. CO sensing does not support the automatic sensitivity testing and drift compensation used with photoelectric sensors, so end of life is a fixed date-code-based lifetime. The sensor keeps functioning after the Expired trouble appears, but replacement is required to ensure detection accuracy. Fit a 4098-9747 CORC per CORC Replacement Instructions 579-791.
-
Head removal is monitored: the interchangeable sensor head features tamper monitoring, and removing it — which is how you reach the CO cartridge — causes a trouble condition.
-
Choose the toxic gas point type carefully: CO Toxic Gas operation can be set as Supervisory, Priority 2 or Utility. Johnson Controls does not recommend Supervisory if the signal is communicated off-site, and prefers Priority 2 in that case.
-
Duct applications are excluded: duct detection modes are not applicable and are not available with CO sensor bases.
-
Placement: follow NFPA 72 for the fire sensor and NFPA 720 for CO. NFPA 720 places a CO alarm or detector centrally outside each separate sleeping area, in the immediate vicinity of the bedrooms. On smooth ceilings a 30 ft (9.1 m) smoke sensor spacing can be used as a guide.
-
Surface mounting: use a 4 in. square box with a single gang RACO No. 787 adapter plate or a 4 in. octagonal box; both also require the 4098-9832 adapter plate, which mounts inverted.
-
Functional testing: a CO test mode at the panel disables the multi-sensor analysis algorithms so each sensing technology can be tested individually. CO testing uses a Solo Model 332 aerosol dispenser with the Solo C3 CO aerosol canister, or equivalent.
Related models
-
4098-9771 — the same CO base with an integral piezoelectric sounder, 88 dBA minimum at 10 ft, 17 mA at 24 VDC; requires separate 24 VDC or NAC power
-
4098-9747 — the CO Replacement Cartridge (CORC), the field-replaceable CO sensing element for this base
-
4098-9714 / 4098-9764 / 4098-9733 — the photoelectric, photo/heat multi-sensor and heat sensor heads this base accepts
-
4905-9835 — Temporal Code Module providing temporal code 3 for fire and temporal code 4 for toxic CO alarms on a sounder base (data sheet S4905-0006)
-
4098-9832 / 2098-9808 / 4098-9822 — adapter plate, remote red LED alarm indicator, and unsupervised DPDT relay tracking base LED status (2 A at 30 VDC power limited, 1/2 A at 120 VAC non-power limited, 13 mA alarm current)
Specifications taken from the Johnson Controls / Simplex data sheet "Multi-Point Peripherals — TrueAlarm CO Sensor Bases for Smoke, Heat, and Photo/Heat Sensors using IDNet Communications," document S4098-0052 Rev. 6 (05/2025). Manufacturer specifications are subject to change without notice.
