Instructions 95-8353-05 Unitized Single Frequency Infrared Fire Detector/Controller U7698B Detector Electronics Corporation 6901 West 110th Street • Minneapolis, Minnesota 55438 USA Tel: 952.941.5665 or 800.765.3473 • Fax: 952.829.
Table of Contents SYSTEM APPLICATION ............................................1 List of Illustrations FEATURES.................................................................1 Figure 1 DESCRIPTION ...........................................................1 Flame Detection ...................................................1 Outputs.................................................................2 oi Feature ............................................................3 Detector Enclosure............
DET-TRONICS INSTRUCTIONS ® Unitized Single Frequency Infrared Fire Detector/Controller U7698B SYSTEM APPLICATION The U7698B Unitized Single Frequency Infrared (IR) Fire Detector/Controller with manual Optical Integrity (oi) is a completely unitized fire detection device that incorporates all detection, signal processing, and switching components in a single enclosure. The U7698B provides reliable fire protection in areas that can present problems for other types of optical detectors.
These characteristics are important because fire is a chemical process, and chemical processes can vary significantly, depending on the elements and conditions. A simple fire detector can be designed to detect any one of these elements, but unless this detector is able to discriminate, it will be subject to false alarms. Discrimination can be achieved by using more than one element as criteria to detect a fire. A flicker filter checks for flame flicker.
Two LEDs are located inside the detector viewing window and are illuminated whenever the fire relay is energized. DETECTOR ENCLOSURE The U7698B features an explosion-proof housing that is designed for installation in hazardous locations in both indoor and outdoor environments. The detector is not affected by adverse weather conditions such as wind, rain, snow, high humidity, or extremes of temperature or pressure.
FLAME SENSITIVITY— The U7698B detects a 1 foot by 1 foot gasoline fire at 65 feet, a 1 foot by 1 foot diesel fire at 60 feet, a 1 foot by 1 foot methanol fire at 50 feet. MOUNTING KEYHOLES (2) 2.0 (50.8) APART (SEE DETAIL "A") 1.0 (25.4) 1.0 (25.4) 0.28 (7.14) 0.5 (12.7) 5.25 (133.3) RESPONSE TIME— The response time of the detector is a function of fuel, fire size, distance, and orientation of the fire source.
Any object with a temperature greater than 0° Kelvin (–273°C) emits infrared radiation. The hotter the object, the greater the intensity emitted between 4.2 and 4.7 microns. The U7698B ignores steady state infrared sources that do not have a flicker frequency characteristic of a fire. However, it should be noted that if these steady state infrared sources are hot enough to emit adequate amounts of infrared radiation in the 4.2 to 4.
Although the infrared detector is less affected by smoke than other detectors, the U7698B should not be placed where rising CO 2 and particulates can obscure its vision. For indoor applications, if dense smoke is expected to accumulate at the onset of a fire, mounting the detector on a side wall a few feet (1 meter) down from the ceiling will normally allow enough time for the unit to respond before it is affected by rising smoke.
CONDUIT ENTRY TERMINAL BLOCK MOUNTING BRACKET IR MODULE TERMINAL HOUSING CONNECTOR PLUG BULKHEAD JUMPER PLUG SENSOR HOUSING A1292 Figure 6—U7698B Detector/Controller Assembly vibration and suitable to receive 1/4 inch (M6) screws with a length of at least 1 inch (25 mm). 3. If the unit is equipped with a cover locking clamp, loosen it with a 5/32 hexagonal (Allen) wrench and move the clamp “catches” out of the blind holes located in the bulkhead. See Figure 7.
5. Route the field wiring through the detector conduit entry. NOTE The two oi lamps should be at the top of the detector (when viewed from the front) and the opening on the oi ring should be directly opposite the test lamps. This will ensure proper operation of the oi system and also minimize the accumulation of moisture and contaminants between the oi ring and the viewing window. 6. Attach the wires to the appropriate screw terminals on the terminal block.
FIRE ALARM PANEL ALARM INPUT oi TEST 24 VDC + – + – oi SPARE SPARE NO FAULT COM NC F A U L T * F I R E NO COM NC U7698B + – oi SPARE SPARE NO COM * FAULT RELAY SHOWN DE-ENERGIZED ** NOTE: END OF LINE RESISTOR VALUE MUST BE NC F A U L T * F I R E NO COM EOL DEVICE** NC A MINIMUM OF 5 WATTS WITH 2 WATT MAXIMUM DISSIPATION. NOTE: SERIES FIRE RESISTOR, IF USED, MUST BE A MINIMUM OF 7 WATTS WITH A 0.7 WATT MAXIMUM DISSIPATION.
can vary considerably, depending on the amount and nature of contaminants that are present in the environment. CAUTION Any extinguishing equipment connected to the system must be disabled when the system is tested to prevent unwanted actuation of this equipment. A coating of lubricant should also be applied to the threads on the detector enclosure before re-assembling the detector. This will both lubricate the threads and help to prevent moisture from entering the detector housing.
d. Check the jumper plug on the replacement IR module for proper position, then install the module in the bulkhead (with the oi test lamps positioned at the top of the detector). Attach the connector plug. ORDERING INFORMATION e. Ensure that the O-rings at the base of the sensor housing are positioned correctly and in good condition. (Refer to the “Maintenance” section of this manual for complete information regarding care of O-rings.
Printed in USA Detector Electronics Corporation 6901 West 110th Street • Minneapolis, Minnesota 55438 USA Tel: 952.941.5665 or 800.765.3473 • Fax: 952.829.
