System Sensor 2412TH - User Manual

This document describes several models of direct wire smoke detectors from System Sensor, including ionization and photoelectronic types, with and without fixed heat detection and audible signals.

Function Description:

The System Sensor 1400 series consists of dual-chamber ionization smoke detectors that utilize state-of-the-art, unipolar sensing chambers. These detectors are designed for open area protection and are compatible with UL-listed, 2-wire control panels. They feature a latching alarm that can only be reset by a momentary power interruption. An integrated LED provides local visual status indication, blinking every ten seconds in standby and lighting continuously in alarm. These detectors also offer a provision for connecting an optional Model RA400Z Remote Annunciator, which provides a supplementary visual alarm indication and mounts to a single gang box.

The System Sensor 1412 and 1424 models are dual-chamber ionization smoke detectors designed for open area protection and use with UL-listed, 4-wire control panels. The 1412 operates at 12VDC, and the 1424 operates at 24VDC. Like the 1400 series, they are latching type system detectors, requiring a momentary power interruption to reset. An LED blinks every 10 seconds in standby and latches on continuously in alarm. Each detector includes one Form A (SPST-NO) contact for the alarm-initiating circuit and one Form C (SPDT-NO/NC) set of auxiliary contacts. Power supervision is achieved by installing a Power Supervisory End-of-Line Relay Module (A77-716) at the end of the detector power loop. A power failure or break in the loop de-energizes the EOL Module, triggering a trouble signal at the control panel.

The System Sensor 2400 and 2400TH are photoelectronic smoke detectors that use state-of-the-art, optical sensing chambers. They are designed for open area protection and are compatible with UL-listed 2-wire control panels. The 2400TH model additionally features a restorable, built-in, fixed temperature (135°F) thermal detection unit. These detectors are UL 268 listed and are latching type, requiring a momentary power interruption for reset. An LED blinks every 10 seconds in standby and latches on continuously in alarm. They also provide an output for connecting an optional Model RA400Z Remote Annunciator.

The System Sensor 2412AT, 2424AT, and 2424AIT are photoelectronic smoke detectors with fixed heat detection, listed to UL 268, and designed for open area protection with UL-listed, compatible, 2-wire control panels. The 2412AT operates at 12 VDC, while the 2424AT and 2424AIT operate at 24 VDC. These sensors utilize a light scattering principle with a unique photo-optic sensing chamber. They include restorable 135°F fixed-temperature heat detection. The 2400AT and 2412AT/2424AT heat detection units are integrated with the photoelectronic sensor, while the 2424AIT's heat detection unit is isolated and can be monitored separately. Additionally, a piezoelectric horn in each detector produces an interrupted, 85 dBA tone when the individual detector alarms or when the supply voltage polarity is reversed. An LED provides a local alarm indication, remaining on when the supply polarity is reversed. A screw terminal is provided for a remote LED annunciator (RA400Z). These are latching type detectors, reset by momentary power interruption. Each detector contains one Form A (SPST-NO) contact for the alarm-initiating circuit and one set of Form C auxiliary contacts. Power supervision is achieved by installing a Power Supervisory End-of-Line Relay Module (A77-716) at the end of the detector power loop.

Important Technical Specifications:

Direct Wire Ionization Smoke Detector:

Diameter: 5.5 inches (140 mm)
Height: 3.12 inches (80 mm)
Weight: 0.7 lb. (310 g)
Operating Temperature: 0° to +49°C (32°F to 120°F)
Operating Humidity: 10% to 93% Relative Humidity, Noncondensing
System Voltage: 12/24 VDC
Standby Ratings: 8.5 VDC Minimum; 35 VDC Maximum; 100 uA Maximum
Alarm Ratings: 4.2 VDC Minimum at 10 mA; 6.6 VDC Minimum at 100 mA (current limited to 100 mA max by control panel)
Reset Voltage: 2.5 VDC Minimum
Reset Time: 0.3 S Maximum
Start-up Time: 35 S Maximum

and 1424 Direct Wire Ionization Smoke Detectors:

Diameter: 5.5 inches (14 cm)
Height: 3.12 inches (8.0 cm)
Weight: 0.7 lb (310 gm)
Operating Temperature: 0° to +49°C (32° to 120°F)
Operating Humidity: 10% to 93% Relative Humidity Non-condensing
Relay Contact Ratings (Resistive or Inductive 60% power factor load):
- Form A: 2.0A @ 30VAC/DC
- Form C: 0.6A @ 110VDC, 2.0A @ 30VDC; 1.0A @ 125VAC, 2.0A @ 30VAC (Canadian installations: 2.0A @ 30VAC/DC)
System Voltage: 12 (1412) / 24 (1424) DC (4V Maximum Ripple)
Supply Voltages: 11.3 VDC Min (1412) / 20 VDC Min (1424); 17.3 VDC Max (1412) / 29 VDC Max (1424)
Standby Current: 100 µA Maximum
Alarm Currents: 35.2 mA Min (1412) / 21.3 mA Min (1424); 77.0 mA Max (1412) / 40.6 mA Max (1424)
Reset Time: 0.3 Seconds
Start-up Time: 30 Seconds

and 2400TH Direct Wire Photoelectronic Smoke Detectors:

Diameter: 5.5 inches (140 mm)
Height: 3.14 inches (80 mm); Add 0.5 inches (13 mm) for 2400TH
Weight: 0.7 lb. (310 gm)
Operating Temperature Range:
- Model 2400: 0° to +49°C (32° to 120°F)
- Model 2400TH: 0° to 38°C (32° to 100°F)
Operating Humidity Range: 10% to 93% Relative Humidity Non-condensing
Maximum Air Velocity: 3000 ft/min (15m/s)
System Voltage: 12/24 VDC
Standby Ratings: 8.5 VDC Minimum; 35 VDC Maximum; 120 µA Maximum
Alarm Ratings: 4.2 VDC Minimum at 10 mA; 6.6 VDC Minimum at 100 mA (current limited to 100mA max by control panel)
Reset Voltage: 2.5 VDC Minimum
Reset Time: 0.3 S Maximum
Start-up Time: 34 S Maximum

2400AT and 2400AIT Direct Wire Photoelectronic with Fixed Heat Smoke Detectors:

Diameter: 5.5 inches (140 mm)
Height: 3.19 inches (81 mm); add 0.5 inches (13 mm) for thermal units
Weight: 0.7 lb. (310 g)
Air Velocity: 3000 ft/min (15 M/s)
Operating Temperature: 0°C to 38°C (0° to 100°F)
Operating Humidity: 10% to 93% Relative Humidity, noncondensing
Audible Signal: 85dBA minimum interrupted tone when in alarm or supply voltage polarity is reversed
Fixed Temperature Thermal: 135°F (57°C)
System Voltage: 24 VDC
Start-up Capacitance: .02 µF Maximum
Start-up Time: 36 Sec. Maximum
Voltage Limits: 10 – 32 VDC
Current Limits:
- Standby: 120 µA Maximum; 100 µA Nominal
- Alarm Current: 15mA at 10V; 67mA at 32V; 48mA at 24V
- Reversed Supply: 5mA at 10V; 19mA at 32V; 15mA at 24V (Detector not in Alarm)
Alarm Impedance: 666 ohms Maximum; 478 ohms Minimum
Alarm Signal: 15mA Minimum in Alarm

2412AT, 2424AT, and 2424AIT Direct Wire Photoelectronic with Fixed Heat Smoke Detectors:

Diameter: 5.5 inches (14 cm)
Height, with Thermal: 3.19 inches (8.1 cm)
Weight: 0.7 lb (310 g)
Operating Temperature: 0° to 38° C (32° to 100° F)
Operating Humidity: 10% to 95% Relative Humidity Non-condensing
Maximum Air Velocity: 3000 Ft./Min. (15 M/S)
Audible Signal: 85dBA minimum interrupted tone when individual unit is in alarm or when the supply voltage is reversed.
Operating Voltage: 12VDC (2412AT) / 24VDC (2424AT or 2424AIT)
Current:
- Standby: 120 µA Max.
- Alarm: 51mA (2412AT) / 43mA (2424AT or 2424AIT) (Add 7mA Maximum with RA400Z Remote Annunciator LED)
- Reversed Supply: 8mA
Start-up Time: 36 seconds maximum
Relay Characteristics: One Form A (SPST-NO) for alarm initiation 1.25A at 30 VAC/DC
Reset Time: 0.3

Usage Features:

Mounting: All detectors are supplied with a mounting bracket kit that allows direct mounting to 3-1/2 inch or 4 inch octagonal, 1-1/2 inch deep electrical boxes, or to a 4 inch square electrical box using a plaster ring.
Wiring: All wiring must comply with the National Electrical Code and local codes. Color-coded conductors are recommended to prevent errors. For signal wiring, AWG 18 is recommended, but screws and clamping plates can accommodate up to AWG 12. Twisted pair wiring for power loops is recommended to minimize electrical interference. Loop resistance specifications from the control panel manufacturer must be consulted.
Tamper-resistant Feature: Detectors include a tamper-resistant tab on the mounting bracket. Breaking off a smaller tab at the scribed line makes the detector tamper-resistant, preventing removal without a tool. To remove a tamper-resistant detector, a small screwdriver must be used to depress the tab in the slot and turn the detector counter-clockwise.
Testing:
- Recessed Test Switch: A test switch is located on the detector housing. Pushing and holding it with a 0.1 inch maximum diameter tool should cause the LED to light (and horn to sound for audible models) within 5 seconds (30 seconds for 1412/1424 models).
- Test Module (System Sensor Model No. MOD400R/MOD400): Used with an analog or digital voltmeter to check detector sensitivity as described in the test module manual.
- Aerosol Generator (Gemini 501): Set to represent 4%/Ft. to 5%/Ft. obscuration. Apply aerosol until the unit alarms.
- Calibrated Test Card (R59-18-00) (Photoelectronic models only): Involves removing the cover, inserting the "NO ALARM" end of the card into the test slot, sliding it counter-clockwise (detector should not alarm within 20 seconds), then removing and inserting the "ALARM" end (LED should latch on within 20 seconds, initiating an alarm at the panel).
- Direct Heat Test (2400TH, 2412TH, 2424TH, 2400AT, 2400AIT, 2412AT, 2424AT, 2424AIT only): Use a low-powered heat gun or blow dryer, aiming heat across the bimetallic collector from about 12 inches (30 cm) away. The detector should latch in alarm when the temperature rises above 135°F. The bi-metallic collector will self-restore after cooling.
Dust Covers: Can be used to limit dust entry, but must be removed before placing the system in service or before beginning remodeling/heavy construction.

Maintenance Features:

Cleaning:
1. Notify authorities that the system is temporarily out of service and disable the zone.
2. Remove the detector screen and cover assembly by depressing three lock prongs, rotating clockwise, and pulling away (System Sensor CRT400 cover removal tool recommended).
3. Remove the screen from the cover.
4. Use a vacuum cleaner to remove dust from the screen, cover, and sensing chamber (and vaned chamber piece for photoelectronic models).
5. Snap the screen into the cover, then place the cover and screen assembly on the detector, turning clockwise until locked in place.
6. Test the detector as described under TESTING.
7. Notify authorities that the system is back online.
Regular Testing: Detectors must be tested after installation and following periodic maintenance.
Replacement: Smoke detectors contain electronic parts that can fail over time. They should be replaced after 10 years of service.
Warranty: System Sensor provides a three-year limited warranty from the date of manufacture, covering defects in materials and workmanship under normal use and service.