CHAPTER 5 MAINTENANCE
Routine Maintenance
The UVU-140-A & UVU-140-AR fire detectors require no periodic calibration. To maintain maximum sensitivity, the viewing window and reflector should be cleaned on a routine basis depending on the type and amount of contaminants in the area.
The rubber o-ring on the detector housing is used to ensure the detector is watertight. The housing should be opened periodically and the o-ring inspected for breaks, cracks or dryness. To test the o-ring, remove it from the detector housing and stretch it slightly. If cracks are visible, the o-ring should be replaced. If it feels dry to the touch, a thin coating of lubricant should be applied. When re-installing the o-ring, be sure that it is properly seated in the groove on the housing.
The o-ring must be properly installed and in good condition to prevent water from entering the detector and causing failure. The life expectancy of rubber o-rings varies, depending on the type and amount of contaminants present in the area. The person who maintains the system must rely on experience and common sense to determine how frequently the rings should be inspected. A coating of lubricant should also be applied to the enclosure threads before reassembling the detector to help prevent moisture from entering.
CAUTION:
The o-ring should be lubricated with polyalphaolefin grease, such as GRS-450 made by CPI Engineering. Silicone based lubricants should never be used if catalytic type combustible gas sensors are being used in conjunction with the UV detectors, since silicone lubricant on or near the combustible gas sensor will cause permanent damage to the sensing element.
Troubleshooting
The automatic vi (visual integrity) feature continuously checks the detector for correct response. If a problem is detected, Table 4 shows the current output levels for various situations.
Cleaning Viewing Window and Reflector
When cleaning the viewing window and reflector use a clean, lint free cloth and the cleaning solution provided with the detector. Use only recommended cleaning solutions, as some cleaners can leave a residue that can block UV radiation.
Repositioning vi Adjustment Allen Screw
The UV sensor module has an adjustable Allen Screw. This adjustable Allen Screw controls the amount of light released from the vi source during visual integrity testing. To increase the amount of UV light released, turn the Allen Screw counter-clockwise, this will open the orifice and allow more light to pass through. An ideal setting with a clean lens and reflector would yield an analog output of 12mA during the manual vi test, which represents an excellent response level when performing a manual vi check.
