OVERVIEW
DETECTION PATTERNS
OS-551/551T
INSTALLATION INSTRUCTIONS
APPLICATION NOTES
PIR sensor is more sensitive to the movements
“crossing” the detection zones than “toward” or
“away” the sensor unit. Avoid placing the sensor in line
with the path of occupant, if possible.
PIR sensor cannot “see” the movements behind
obstacles, such as furniture, shelf, glass or partitions.
As a general rule, ensure to place the sensor at where
the occupant could have clear view of the sensor.
For open office areas with partition which could
block the sensor view to occupant movements,
it is recommended to place the sensors over the
intersection of multiple workstations. For large areas
of open office or space, place multiple sensors so that
there is overlap coverage with each adjacent sensor.
1.
2.
3.
DIMENSIONS
The OS-551/OS-551T is a low voltage occupancy
sensor designed to signal the occupancy status for
area lighting, or HVAC control, for energy efficient
building management. The sensor is operated by
24VAC/DC power supply from an IR-TEC power pack,
or building management system, and provides a dry
contact signal for control of the connected lighting or
HVAC equipment.
A cutting edge dual element pyroelectric infrared
sensor and unique Fresnel lens are employed to
provide superior occupancy sensing capability. When
the sensor detects an occupant’s presence, the relay
contact output will be engaged until the OFF-delay
time expires. If the sensor is applied to control the
operation of HVAC systems, the ON-delay can be
enabled to prohibit short-cycle restarting or unwanted
load activation. Both ON and OFF delays can be
easily set through jumper pin positioning.
In addition to the standard features of OS-551, the
OS-551T further provides high/low temperature
setbacks to help maintaining room temperature
within the range during unoccupied period. The
sensor comes with a multi-directional bracket for easy
mounting on the ceiling or wall, which also allows
horizontal/vertical sensor angle adjustment to achieve
optimal coverage.
Top View
Side View
8’
8’
25’
50’
110°
SPECIFICATIONS
Power supply
Current drain
Output contact
Infrared sensor
Detectable speed
Mounting height
Detection range
ON delay setting
OFF delay setting
High/low setback*
Op. humidity
Op. temperature
Dimensions
24 ± 2 VAC/DC
7 mA @24VAC
Form C, Max. 30 VDC, 0.2A
Dual element pyroelectric infrared sensor
0.33 ~ 10 ft/sec. (0.1 ~ 3 m/sec.)
6 ~ 12 ft. (1.8 ~ 3.6 m)
110°, 50 ft @ 77°F (25°C)
0(disabled)/10”/30”/1’/5’/10’ selectable
10”/1’/5’/10’/20’/30’ selectable
High: 85/82/79°F, Low: 59/55/51°F
Max. 95% RH
-4°F ~ 122°F (-20°C ~ 50°C)
4.4” x 2.6” x 1.8” (112 x 66 x 45 mm)
*Only available on OS-551T
The sensor will enter a warm-up period when power is
first applied and then operate as described below.
SENSOR OPERATION
The sensor will enter into standby mode after the
warm-up period expires. The LED will flash if any
jumper is not properly placed on the pin.
A. Standby mode
If the ON-delay is enabled, the sensor will enter this
mode when it first detects the presence of an occupant.
Any further motion detected during the ON-delay
mode will NOT reset the timer.
B. ON delay mode
When the ON-delay expires, the sensor will enter into
the 1-minute waiting period. If no motion is detected
within this time period, the sensor will return to standby
mode. If motion is detected within this time period,
the sensor will engage the relay contact and enter into
OFF-delay mode.
C. 1-minute waiting
The OFF-delay is the time
period that the sensor
will hold its relay contact
engaged. Every motion
detected during this time
period will reset the timer. The
sensor will return to standby
mode if no further motion
is detected during this time
period and the relay will be
disengaged.
Note:
The OS-551T will
activate its relay contact output
automatically when room
temperature exceeds the
high/low setback range when
controlling in an HVAC system.
D. OFF delay mode
Standby
mode
A.
Detection
Detection
No
Detection
ON delay
mode
B.
OFF delay
(Relay Output)
D.
1-minute
waiting
C.
4.4”
2.6”
1.8”
Low Voltage Occupancy Sensor
P/N: 058-55101-003
Printed in Taiwan
www.irtec.com
This product may be covered by one or more U.S. patents or patent applications.
Please visit www.irtec.com for more information.
Turn power OFF at circuit breaker before connecting
Power Pack or Sensor.
CAUTION
Wire all Class 2 circuits using types CL3, CL3P,
CL3R, or equivalent conductors.
INDOOR USE ONLY
Coupez l'alimentation au disjoncteur avant d'installer
Power Pack ou capteurs.
Câble toute classes 2 circuits CL3, CL39, CL3R ou
conducteur équivalent.
PRUDENCE
Utilisation a L'interieur Uniquement
