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IS 14669:1999 is the Indian Standard (BIS) for overspeed governors for lifts. This standard specifies the requirements for the design, construction, and testing of overspeed governors used in electric and hydraulic lifts. It details critical safety parameters like tripping speeds, constructional integrity, rope specifications, and testing procedures to ensure the governor can reliably activate the safety gear in an overspeed event.
Specifies the requirements for overspeed governors used in lifts to activate the safety gear.
! The tripping speed is a critical setting that must be verified and sealed during commissioning and periodic inspections.
! Ensure the governor rope is correctly tensioned and free from excessive wear, as low tension or a worn rope can cause slippage and failure to trip.
! The type of governor (e.g., pendulum, centrifugal) must be compatible with the type of safety gear (instantaneous or progressive) it is designed to operate.
EN 81-20:2020CEN (European Committee for Standardization), Europe
HighCurrent
Safety rules for the construction and installation of lifts - Lifts for the transport of persons and goods - Part 20: Passenger and goods passenger lifts
Specifies safety requirements for lift components, including overspeed governors.
ASME A17.1-2019/CSA B44-19ASME (American Society of Mechanical Engineers) / CSA (Canadian Standards Association), USA/Canada
HighCurrent
Safety Code for Elevators and Escalators
Contains detailed requirements for the design and testing of elevator governors and safety systems.
ISO 8100-1:2019ISO (International Organization for Standardization), International
HighCurrent
Lifts for the transport of persons and goods - Part 1: Safety rules for the construction and installation of lifts - Lifts for the transport of persons and goods passenger lifts
Harmonizes global standards, largely based on EN 81-20, including overspeed governor rules.
EN 81-1:1998+A3:2009CEN (European Committee for Standardization), Europe
HighWithdrawn
Safety rules for the construction and installation of lifts - Part 1: Electric lifts
Previous European standard, whose requirements are conceptually very similar to IS 14669:1999.
Key Differences
≠Modern standards like EN 81-20 have extensive requirements for protection against unintended car movement (UCMP), which often integrates with the overspeed governor system. IS 14669:1999 does not address UCMP.
≠The formula for calculating the maximum tripping speed differs. IS 14669 (referencing IS 4666) uses a tiered formula, while EN 81-20 uses a different, albeit structurally similar, formula for speeds above 0.63 m/s.
≠EN 81-20 specifies that for speeds >1 m/s, the electrical safety switch must trip at least 10% below the mechanical tripping speed. IS 14669 is less prescriptive, only requiring the switch to operate at or before the governor trips.
≠EN 81-20 includes specific requirements to prevent the governor rope from leaving its pulleys and to manage rope slip, which are more detailed than the general provisions in the older Indian Standard.
Key Similarities
≈The fundamental requirement for a mechanical device (overspeed governor) to detect downward overspeed and engage a safety gear to stop the car is a core principle in all standards.
≈All standards require the governor to be equipped with an electrical safety switch that cuts power to the drive motor and brake circuit at or before the mechanical tripping speed is reached.
≈The requirement to seal the overspeed governor after setting and testing to prevent unauthorized tampering is a common safety measure across all listed standards.
≈The specified minimum values for key physical parameters like governor rope diameter (≥6 mm) and the force exerted by the governor to trip the safety gear (≥300 N) are identical.
Parameter Comparison
Parameter
IS Value
International
Source
Minimum Tripping Speed
≥ 115% of rated speed
≥ 115% of rated speed
EN 81-20:2020 (5.6.2.2.1.1 a)
Maximum Tripping Speed (for rated speed V > 0.75 m/s)
V + (0.25 + 0.25/V) m/s (as per IS 4666)
1.15V + 0.25/V m/s (for V > 0.63 m/s)
EN 81-20:2020 (5.6.2.2.1.1 b)
Minimum Governor Rope Diameter
≥ 6 mm
≥ 6 mm
EN 81-20:2020 (5.6.2.2.1.4)
Minimum Tripping Force on Safety Gear
≥ 300 N
≥ 300 N
EN 81-20:2020 (5.6.2.2.1.3)
Minimum Governor Rope Tensioning Force
≥ 300 N
≥ 300 N
EN 81-20:2020 (5.6.2.2.1.5)
Pitch Diameter of Governor Sheave to Rope Diameter Ratio
≥ 30
≥ 30
EN 81-20:2020 (5.6.2.2.1.4)
Electrical Switch Operation
At or before governor trips.
At a speed less than mechanical tripping speed (at least 10% below for V > 1 m/s).
EN 81-20:2020 (5.6.2.2.1.6 b)
⚠ Verify details from original standards before use
Key Values6
Quick Reference Values
Minimum tripping speed115% of rated speed
Maximum tripping speed (v rated > 1 m/s)v_rated + 0.25 / v_rated (in m/s)
What is the main purpose of an overspeed governor?+
To detect when the lift car's speed exceeds a safe limit and to mechanically trip the safety gear, which then stops the car by clamping onto the guide rails.
At what speed range should the governor for a 1.0 m/s lift trip?+
It must trip at a speed between 1.15 m/s (115% of rated speed) and 1.25 m/s (calculated as 1 + 0.25/1), as per Clause 4.
Is an electrical switch required on the governor?+
Yes, an overspeed switch must be provided on the governor to cut power to the motor and apply the brake before or at the moment the governor trips mechanically (Clause 5.4).
What tests are required for an overspeed governor?+
The standard mandates type tests by the manufacturer to certify the design and routine tests on-site during commissioning and periodic inspections to verify the tripping speed and function (Clause 6).