This standard outlines the specifications, testing procedures, and performance benchmarks for heat-responsive fire detectors utilized within automatic fire alarm systems. It encompasses both resettable and non-resettable variants, including fixed temperature and combined rate-of-rise and fixed temperature detectors. The guidelines ensure dependable fire detection through heat sensing by addressing response characteristics, environmental resilience, and electrical parameters.
Overview
This standard outlines the specifications, testing procedures, and performance benchmarks for heat-responsive fire detectors utilized within automatic fire alarm systems. It encompasses both resettable and non-resettable variants, including fixed temperature and combined rate-of-rise and fixed temperature detectors. The guidelines ensure dependable fire detection through heat sensing by addressing response characteristics, environmental resilience, and electrical parameters.
Audience
Contents
Structure
This section defines the scope of the standard, detailing the testing methods for vibration and response characteristics of heat-sensitive detectors. It includes instructions on rounding off test results and references specific clauses and appendices for vibration tests and directional dependence assessments.
Clarifies the essential terms used throughout the standard, such as vibration, response time, and directional dependence. It also outlines the rules for rounding off numerical test data in accordance with IS 2-1960.
Describes the classification of detectors into three grades based on their response times, differentiates between resettable and non-resettable detectors, and specifies testing requirements including sample sizes and validity periods.
Summarizes the key performance tests such as vibration, corrosion, directional dependence, and response time. This section includes test sample sizes, test conditions, and acceptance criteria.
Details the specific tests, associated clauses, detector quantities, temperature rise rates, and conditions for both resettable and non-resettable detectors. It also highlights essential specifications for plastic components and testing orientations.
Lists the technical and operational information that must accompany detectors, including type, sensing mechanism, installation advice, maintenance instructions, and electrical interface details. It also covers sampling and testing protocols for production batches.
Specifies the mandatory markings for detectors, such as manufacturer details, type, production year, grading color codes, and fusible link indications. The section also explains optional certification markings and their significance.
Outlines the method to measure detector response time and directional dependence using controlled wind tunnel conditions. It includes test orientations, temperature rise rates, and acceptance limits.
Describes the vibration test setup, parameters including frequency and amplitude, duration, and resonance testing procedures to verify mechanical robustness.
Details the environmental setup, chemical solutions, temperature controls, and test durations for assessing detector resistance to corrosive atmospheres and salt spray.
Defines the procedure for mechanical shock testing including apparatus details, drop height, and acceptance criteria ensuring detectors withstand impacts without false alarms.
Explains the testing process for verifying detector performance under fluctuating supply voltages, including response time limits and false alarm prevention.
Frequently Asked
The standard specifies two primary categories of heat-responsive fire detectors used in automatic fire alarm systems: fixed temperature detectors, which activate when ambient temperature hits a set point; and combined rate-of-temperature-rise and fixed temperature detectors, which respond either to a rapid temperature increase or when a specific temperature threshold is reached. Both categories include resettable and non-resettable models.
Response time is measured by placing detectors in a controlled chamber with an air velocity of 0.8 ± 0.1 m/s at 28°C, connected to indicating/control equipment. Detectors are initially cooled to 0 ± 1°C at a maximum rate of 1°C per minute and held for an hour, then stabilized at 27 ± 3°C for 5-6 hours. Response times are recorded for temperature increases at 3°C/min and 20°C/min, with the interval from temperature rise initiation to activation noted to ±0.5 seconds. Acceptable limits require no alarms during low temperature exposure and response time variation after testing not exceeding 15% or 10 seconds, whichever is greater.
Detectors must successfully undergo humidity testing at 30 ± 2°C with 80 ± 5% relative humidity for 7 days, ensuring response times do not exceed 1.6 times the original and no false alarms occur. Additionally, corrosion tests lasting 16 days involving sulphur dioxide exposure and salt spray are required, with detectors expected to signal continuous faults immediately or alarm within the upper limits of Grade 3 response times.
Detectors must be clearly and permanently marked with the manufacturer's name or trademark, detector type and description including number, manufacturing year, and grading color code—green for Grade 1, yellow for Grade 2, and red for Grade 3. If equipped with a fusible link, this must be indicated. Optionally, the detector may bear the Standard Mark certifying compliance with BIS quality and inspection standards.
Resettable detectors are designed to return to normal operational condition after an alarm event without needing any component replacement once the triggering condition has ceased. In contrast, non-resettable detectors require replacement or renewal of certain components after activation to restore detection capability. Both types are covered under the standard, including fixed temperature and rate-of-rise detectors.
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