Sr. Nos.

TOPICS UL STANDARDS EN 54 STANDARDS

1 Standby Power supply under normal quiescent load.

As per NFPA 72-2002 with an effect from August 8, 2002, the committee has revised the entire power supply section. The fire alarm system no longer needs to provide 60 hours of standby power. The requirement says only 24 hours of secondary power under normal quiescent load.

72 hours under normal quiescent load.

2 standby power supply under maximum connected load.

In the latest edition of NFPA - 72 the committee has removed the reference of two-hour of intermittent operation and only requires the 15 minutes operation of the system at maximum connected load.

30 minutes operation of the fire alarm system under maximum connected load.

3 Thermal response coefficient of heat detectors

The committee has deleted the requirement for marking heat detectors with their thermal response coefficient since the testing laboratories could not reach an agreement on a test to determine this coefficient.

As per EN 54 part 5.6 and 8 it is controllable between 1.02 deg C/min to 30 deg C/min.

4 Spacing of linear projected beam-type smoke detector.

Nothing has been mentioned in the revised NFPA 72 - 2002 standard regarding the spacing of beam type smoke detectors.

Can cover an area of 1500 sq. mtr with a spacing of 7.5 on either side as per EN 54 - 14 standards.

5 Life of a smoke detector As per NFPA 72, the smoke detector should be replaced after 10 years of installation.

Depends on the ability to compensate the environmental threshold and manufacturer's data/ recommendations.

6 Maximum temperature for Smoke detectors for Duct Application

As per UL 268A and NFPA 72 and NFPA 90 A the air duct smoke detectors are intended to be installed in ducts where the maximum temperature should not exceed 100 deg F ( 38 deg C).

The maximum temperature can be more that 50 deg C as per EN 54 - 7.

7 Minimum temperature for Smoke detectors for Duct Application

As per UL 268A and NFPA 72 and NFPA 90 A the air duct smoke detectors are intended to be installed in ducts where the minimum temperature should not be less than 32 deg F ( 0 deg C).

The minimum temperature can be - 20 deg C.

8 Fuel Gas detectors for fire detection purposes.

NFPA standard 72 [19] does not provide any guidelines for testing of these detectors in a fire situation.

Proper guidelines have been written by the European standards committee for the use of flame detectors in the buildings. The testing is based on the same series of fires as is used for smoke detectors (TF1 through TF5).

9 Flame detection for gaseous products of combustion (including CO).

NFPA standard 72 [19] does not provide any guidelines for testing of these detectors in a fire situation.

Proper guidelines have been written by the European standards committee for the use of flame detectors in the buildings. The testing is based on the same series of fires as is used for smoke detectors (TF1 through TF5).

10 Redundancy - For system with more than 518 devices there should be some sort of redundancy.