Siemens OOHC941 Installation Instructions Manual

A6V10324661_en--_m SIEMENS Industry, Inc.2020-08-28 Smart InfrastructureInstallation InstructionsModel OOHC941Multi-Criteria Fire/CO DetectorUL268 7th edition listedFigure 1These instructions are written in accordance with theinstallation guidelines of NFPA 72, National Fire AlarmCode and CAN/ULC-S524, The Installation of FireAlarm Systems. The model OOHC941 detector (asshown in Figure 1) meets the VEWFD (Very EarlyWarning Fire Detector) classification and sensitivityrequirements of NFPA 76 (Standard for the FireProtection of Telecommunications Facilities)incorporating a programmable “Alert” (Pre-Alarm)sensitivity threshold of 0.2%/ft obscuration and an“Alarm” sensitivity threshold of 1.0%/ft obscuration.CAUTIONDO NOT install this detection device until all constructionis completed.DO NOT store this detection device where it can becontaminated by dirt, dust, or humidity.DETECTOR PLACEMENTAlthough no specific spacings are set for the detectorsused for a clean air application, for multi-criteria firedetection use 30-foot center spacing (900 sq ft) fromNFPA 72 initiating devices chapter, if practical, as aguide or starting point for a detector installation layout.This spacing, however, is based on ideal conditions–smooth ceiling, no air movement, and no physicalobstructions. In some applications, therefore,considerably less area is protected adequately by eachsmoke detector. This is why it is mandatory to closelyfollow the installation drawings. In all installations placethe detector on the ceiling, a minimum of 6 inches froma side wall, or on a wall, 12 inches from the ceiling. ForCO gas detection applications, follow detectorinstallation requirements in NFPA 72 for Installation ofCarbon Monoxide Detection and Warning Equipment.For thermal detection, use the matrix below:Spacing, Feet Temperature Rating, °F With/without Guard Model50 135, 145, 155, 165, 175With and without STI Guard60 135, 145, 155, 165, 17570 135, 145Drawings provided or approved by Siemens Industry,Inc., or by its authorized distributors are extremelyimportant. The detector placements shown on thesedrawings were chosen after a careful evaluation of thearea that is protected. Such factors as air currents,temperature, humidity, pressure, and the nature of thefire load were carefully considered. Especially notedwere the room or area configuration and the type ofceiling (sloped or flat, smooth or beamed). SiemensIndustry, Inc.’s extensive experience in the design of thesystem assures the best detector placement by followingthese drawings. Sound engineering judgment byqualified personnel must be followed.TO AVOID NUISANCE ALARMSDo not locate the detectors where excessive smokeconcentrations exist under normal conditions, or in areasof prolonged high relative humidity where condensationoccurs.Do not locate the detectors next to an oil burner, orgarage where exhaust fumes can trigger an alarm. Othercauses of false alarm are dust accumulation, heavyconcentrations of steam, heavy pipe or cigar smoke, andcertain aerosol sprays.