What is the standard voltage and frequency for these sirens?

415 Volts AC, 3-phase, 50 Hz (Clause 3.1).

What is the minimum required protection level for the siren's motor?

The motor enclosure must have a degree of protection of at least IP44 as per IS/IEC 60529 (Clause 4.1.2).

What is the audible range of a 3 HP (2.2 kW) siren?

Approximately 1.6 kilometers in still air, as specified in Table 1.

What is the insulation resistance test requirement?

The insulation resistance between windings and the body must be not less than 2 MΩ when measured with a 500V DC megger (Clause 6.3).

IS 1941

: 2000

Functional requirements for electric motor sirens, Part 1: ac 3 phase 50 Hz, 415 volts type

CurrentSpecializedSpecificationFire Safety · Fire Fighting

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This standard specifies the functional requirements and testing methods for three-phase, 415V AC electric motor sirens used for fire alarms and public warning. It covers constructional details, motor specifications, performance criteria like audible range, and the procedures for type, routine, and acceptance tests.

Functional requirements for electric motor sirens, Part 1: ac 3 phase 50 Hz, 415 volts type

Quick Reference Values

Standard Voltage415 V ± 6%

Standard Frequency50 Hz ± 3%

Minimum Degree of Protection (Motor)IP 44

Minimum Insulation Resistance2 MΩ at 500 V DC

High Voltage Test1500 V AC for 1 minute

Audible Range for 2.2 kW (3 HP) Siren1.6 km in still air

Maximum Starting Current6 to 7 times full load current

Practical Notes

The effective audible range mentioned in Table 1 is for ideal 'still air' conditions and will be lower in areas with high ambient noise, wind, or physical obstructions.

Ensure the selected siren's degree of protection (IP rating) is appropriate for the installation location (e.g., outdoor, dusty environment).

Verify that the electrical installation, including starting mechanism (DOL or Star-Delta), is correctly rated for the high starting current of the siren motor.