Chapter 2 Installation; Installation Guidelines - Emerson Rosemount 975 Series Reference Manual

Reference Manual
00809-1400-4975
2 Installation
2.1

Installation guidelines

Installation should comply with NFPA 72E or any other local and international regulations
and standards, as applicable to flame detectors and installation of Ex approved products.
To ensure optimal performance and efficient installation, consider the following
guidelines.
Sensitivity
To determine the level of sensitivity, consider the following:
• Size of fire at the required distance to be detected
• Type of flammable materials
• Proximity to false alarm sources
Wiring
The wire gauge must be designed according to the distance from the detector to the
controller and the number of detectors on the same power line (see
ground
To fully comply with EMC directive and protect against interference caused by RFI and EMI,
the cable to the detector must be shielded and the detector must be grounded. The shield
should be grounded at the detector end.
Spacing and location
The number of detectors and their locations in the protected area are determined by:
• Size of the protected area
• Sensitivity of the detectors
• Obstructed lines of sight
• Cone of view of the detectors
Environment
Dust, snow, or rain can reduce the detector's sensitivity and require more maintenance
activities.
The presence of high intensity emission sources may affect sensitivity.
Aiming the detector
The detector should be aimed toward the center of the detection zone and have a
completely unobstructed view of the protected area.
It is recommended to position the detector tilted down at a 45° angle to maximize
coverage and prevent accumulation of dust and dirt.
Installation should not begin until all conceivable considerations regarding detection
location have been taken into account.
Rosemount 975
cable).
Installation
June 2021
Wire terminals and
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