When can an instantaneous safety gear be used?

Only for lifts with a rated speed not exceeding 0.63 m/s (Clause 5.2.1).

What is the required retardation for a progressive safety gear?

The average retardation must be between 0.2g and 1.0g for the car with its rated load (Clause 6.2).

Does the counterweight need a safety gear?

Yes, if there are accessible spaces under the pit, the counterweight must be fitted with a safety gear (Clause 4.3).

How is a safety gear type-tested?

It is tested via a free-fall drop test on a dedicated test rig to verify stopping distance, retardation, and structural integrity as per the methods in Clause 10.

IS 14668

: 1999

Safety Gears for Lifts

CurrentSpecializedSafety CodeBIMMEP · Lifts, Escalators and Mechanical Handling

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This standard specifies safety requirements for the design, construction, and testing of safety gears used in electric and hydraulic lifts. It covers different types of safety gears, such as instantaneous and progressive, and defines their permissible use based on the lift's rated speed. The code ensures that in an overspeed or free-fall condition, the safety gear can safely stop and hold the lift car or counterweight.

Specifies the requirements for safety gears intended to stop and hold an overspeeding lift car or counterweight on the guide rails.

Quick Reference Values

Maximum rated speed for instantaneous safety gear0.63 m/s

Rated speed above which progressive safety gear is mandatory> 0.63 m/s

Acceptable average retardation for progressive safety gear0.2g to 1.0g

Minimum tripping speed of overspeed governor115% of rated speed

Force to be exerted on safety gear operating rod for trippingnot less than 300 N

Practical Notes

The choice between instantaneous and progressive safety gear is strictly dictated by the lift's rated speed as per Clause 5.

The overspeed governor (covered in IS 14671) and the safety gear are a matched pair; they must be designed and certified to work together.

During testing, the condition of the guide rails (e.g., lubricated or dry) significantly affects the stopping distance and must match the manufacturer's specification.