D200-29-00
1
I56-1909-003R
2251B, 2251TB and 2251TMB
Intelligent Photoelectric Smoke Sensors
INSTALLATION AND MAINTENANCE INSTRUCTIONS
BEfORE INSTALLINg
This sensor must be installed in compliance with the control panel system instal-
lation manual. The installation must meet the requirements of the Authority Hav-
ing Jurisdiction (AHJ). Sensors offer maximum performance when installed in
compliance with the National Fire Protection Association (NFPA); see NFPA 72.
gENERAL DESCRIPTION
Models 2251B, 2251TB and 2251TMB are plug-in type smoke sensors that com-
bine a photoelectronic sensing chamber with addressable-analog communica-
tions. The sensors transmit an analog representation of smoke density over a
communication line to a control panel. Rotary-decade switches are provided
for setting the sensor’s address.
Two LEDs on the sensor are controlled by the panel to indicate sensor status.
An output is provided for connection to an optional remote LED annunciator
(P/N RA400Z). Models 2251TMB and 2251TB combine a photoelectronic sens-
ing chamber and 135°F (57.2°C) fixed temperature heat detector.
The 2251B, 2251TB and 2251TMB require compatible addressable commu-
nications to function properly. Connect these sensors to listed-compatible
control panels only.
SPACINg
System Sensor recommends spacing sensors in compliance with NFPA 72. In
low air flow applications with smooth ceilings, space sensors 30 feet apart.
For specific information regarding sensor spacing, placement, and special ap-
plications, refer to NFPA 72 or the
System Smoke Detector Application Guide,
available from System Sensor.
Duct Applications: 2251B and 2251TB are listed for use in ducts. See Duct Ap-
plications Guide A05-1004-XX for details on pendant mount applications.
NOTE: These products are not listed for use inside duct smoke detectors.
WIRINg gUIDE
All wiring must be installed in compliance with the National Electrical Code,
applicable local codes, and any special requirements of the Authority Having
Jurisdiction. Proper wire gauges should be used. The installation wires should
be color-coded to limit wiring mistakes and ease system troubleshooting. Im-
proper connections will prevent a system from responding properly in the
event of a fire.
Remove power from the communication line before installing sensors.
1. Wire the sensor base (supplied separately) per the wiring diagram, Figure 1.
2. Set the desired address on the sensor address switches, see Figure 2.
3. Install the sensor into the sensor base. Push the sensor into the base
while turning it clockwise to secure it in place.
4. After all sensors have been installed, apply power to the control unit and
activate the communication line.
5. Test the sensor(s) as described in the TESTING section of this manual.
CAUTION
Dust covers provide limited protection against airborne dust particles during
shipping. Dust covers must be removed before the sensors can sense smoke.
Remove sensors prior to heavy remodeling or construction.
SPECIfICATIONS
Operating Voltage Range:
15 to 32 VDC
Standby Current:
300µA @ 24 VDC (one communication every 5 sec. with LED blink enabled)
Maximum Alarm Current (LED on:)
6.5 mA @ 24 VDC
Operating Humidity Range:
10% to 93% Relative Humidity, Non-condensing
Operating Temperature Range:
32°F to 120°F (0°C to 49°C), 2251B; 32°F to 100°F (0°C to 38°C), 2251TB and 2251TMB
Heat Sensor:
135°F Fixed Temperature Electronic Thermistor
Height:
2.0˝ (51 mm) installed in B210LP Base
Diameter:
6.1˝ (155 mm) installed in B210LP Base; 4.1˝ (104 mm) installed in B501 Base
Weight:
5.2 oz. (147 g)
fIgURE 1. WIRINg DIAgRAM:
3
2
1
3
2
1
+
-
-
+
+
-
REMOTE
ANNUNCIATOR
UL
LISTED COM
P
A
TIBLE
CONTROL
P
ANEL
OPTIONAL RETURN LOOP
DO NOT LOOP WIRE
UNDER TERMINAL 1 OR 2.
BREAK WIRE RUN TO
PROVIDE SUPERVISION
OF CONNECTION.
C0147-00
fIgURE 2. ROTARy DECADE ADDRESS SWITChES:
TENS
ONES
9
8
7
6
5
4
3
2
1 0
9
8
7
6
5
4
3
2
1 0
C0146-00
TAMPER-RESISTANCE
Models 2251B, 2251TB and 2251TMB include a tamper-resistant capability
that prevents their removal from the bracket without the use of a tool. Refer to
the base manual for details on making use of this capability.
TESTINg
Before testing, notify the proper authorities that the system is undergoing
maintenance, and will temporarily be out of service. Disable the system to
prevent unwanted alarms.
All sensors must be tested after installation and periodically thereafter. Test-
ing methods must satisfy the Authority Having Jurisdiction (AHJ). Sensors
offer maximum performance when tested and maintained in compliance with
NFPA 72.
The sensor can be tested in the following ways:
A. Functional: Magnet Test (P/N M02-04-01 or M02-09-00)
This sensor can be functionally tested with a test magnet. The test mag-
net electronically simulates smoke in the sensing chamber, testing the
sensor electronics and connections to the control panel.
1. Hold the test magnet in the magnet test area as shown in Figure 3.
2. The sensor should alarm the panel.
Two LEDs on the sensor are controlled by the panel to indicate sensor
status. Coded signals, transmitted from the panel, can cause the LEDs
to blink, latch on, or latch off. Refer to the control panel technical docu-
mentation for sensor LED status operation and expected delay to alarm.
I56-1909-00
3R
3825 Ohio Avenue, St. Charles, Illinois 60174
1.800.SENSOR2; Fax: 630.377.6495
www.systemsensor.com
