IS/ISO 7240 : Part 31 : 2022 Fire Detection and Alarm Systems - Part 31 Resettable Line-Type Heat Detectors
NATIONAL FOREWORD
This Indian Standard (Part 31) which is identical to ISO 7240-31 : 2022 'Fire detection and alarm systems - Part 31: Resettable line-type heat detectors' issued by the International Organization for Standardization (ISO) was adopted by the Bureau of Indian Standards on the recommendation of the Fire Fighting Sectional Committee and approval of the Civil Engineering Division Council.
This Indian Standard is published in various parts. The other parts in this series are:
| Part 2 | Fire detection control and indicating equipment |
| Part 3 | Audible alarm devices |
| Part 4 | Power supply equipment |
| Part 5 | Point-type heat detectors |
| Part 6 | Carbon monoxide fire detectors using electro-chemical cells |
| Part 7 | Point-type smoke detectors using scattered light, transmitted light, or ionization |
| Part 8 | Point-type fire detectors using a carbon monoxide sensor in combination with a heat sensor |
| Part 10 | Point-type flame detectors |
| Part 11 | Manual call points |
| Part 12 | Line type smoke detectors using a transmitted optical beam |
| Part 13 | Compatibility assessment of system components |
| Part 15 | Point-type fire detectors using smoke heat sensors |
| Part 16 | Sound system control and indicating equipment |
| Part 17 | Transmission path isolators |
| Part 18 | Input/output devices |
| Part 20 | Aspirating smoke detectors |
| Part 21 | Routing equipment |
| Part 22 | Smoke-detection equipment for ducts |
| Part 23 | Visual alarm devices |
| Part 24 | Fire alarm loudspeakers |
| Part 25 | Components using radio transmission paths |
| Part 27 | Point-type fire detectors using a smoke sensor in combination with a carbon monoxide sensor and, optionally, one or more heat sensors |
| Part 29 | Video fire detectors |
Resettable line-type heat detectors (RLTHD) have been incorporated into fire alarm systems for a considerable number of years. These detectors are typically used in areas where point-type heat detectors are presented with challenging environmental characteristics and also where access to the detectors can significantly influence the fire alarm system design.
This Indian Standard gives common requirements for the construction and robustness of line-type heat detectors, as well as for their performance under climatic, mechanical, and electrical interference conditions which are likely to occur in the service environment.
This Indian Standard defines the minimum system functionality for RLTHD products. RLTHD are based upon many unique operating principles. It is the intention of this document to define common operating characteristics for each type of RLTHD in conjunction with existing IS/ISO 7240 detector Indian Standards, so that resettable line-type heat detectors have a response behavior comparable to that of point-type heat detectors.
Generally, there are three functional principles employed by RLTHD: Non-integrating systems, integrating systems and for-only detectors; separate subclasses have been created for each of these systems.
The text of ISO standard has been approved as suitable for publication as an Indian Standard without deviations. Certain conventions and terminologies are, however, not identical to those used in Indian Standards. Attention is particularly drawn to the following:
a) Wherever the words 'International Standard' appear referring to this standard, they should be read as 'Indian Standard'; and
b) Comma (,) has been used as a decimal marker while in Indian Standards, the current practice is to use a point (.) as the decimal marker.