BS EN 81-21:2009 pdf free download – Safety rules for the construction and installation of lifts一 Lifts for the transport of persons and goods Part 21: New passenger and goods passenger lifts in existing building.
b) The stopping gear shall be tripped by a mechanical triggering device using a mechanical linkage for the tripping operation:
c) The stopping gear shall be kept tripped by the triggering device and the linkage when the car is at any position above the tripping point;
In case of a release of the stopping gear due to dynamic effects or rescue operations it shall be reengaged when the car moves again in up direction above the tripping point keeping the required safety space;
d) The stopping gear shall be operated positively:
1) Where springs are used they shall act by compression;
2) Where a rope is used the safety factor of the rope shall be in accordance with EN 81 -1:1998, 9.9.6.2 and EN 81-2, 9.10.6.2;
e) The force required to activate the stopping gear shall be at least the greater of the following two values:
1) twice the engagement force of the stopping gear taking into consideration the tolerances due to friction;
2) 300 N;
f) The stopping gear shall operate an electric safety device in conformity with EN 81-1:1998 and EN 81-2, 14.1.2, if it is engaged;
g) When the stopping gear has been tripped its release shall require the intervention of a competent person;
h) After the release, the stopping gear shall be in a condition to operate;
i) The pre-triggered device shall be protected against the accidental insertion of objects, dirt and corrosion;
j) The pre-triggered stopping system shall be able to stop the car and keep it stopped from any speed between zero and the tripping speed of the ascending car overspeed protections means;
k) The maximum retardation by the stopping gear shall not exceed 1 g in the worst condition as validated according to Annex C;
l) When the stopping gear operates, the floor of the car with or without the load uniformly distributed shall not incline more than 5 % from its normal position;
m) The pre-triggered stopping system shall be designed and verified according to the requirements in Annex C.
c) There shall be above the car sufficient space to accommodate a rectangular block not less than 0,50 m x 0,60 m x 0,80 m resting on one of its faces. For lifts with direct roping, the suspension ropes and their attachments may be included in this space, provided that no rope centre-line shall be at a distance exceeding 0,15 m from at least one vertical surface of the block;
d) The value of 0,035 v2 mentioned in a) and b) shall only be taken into account for traction and indirect hydraulic lifts with movable stops.
For hydraulic lifts the upward speed Vm shall be used for calculation of the term 0,035 v2.
5.5.2.4 Operation
The movable stops or the triggering device shall be operated:
a) Automatically at the latest when the safety system (5.5.3) has been activated; or
b) Manually.
5.5.2.4.1 In the case of power failure:
a) The automatic movable stops or the automatic triggering device shall be activated and maintained in the active position at least up to the power restoration;
b) For manually operated movable stops or for manually operated triggering devices, a mechanical safety device shall maintain the car stationary. This device shall be activated and maintained in the active position at least up to the power restoration.
5.5.2.4.2 For traction drive lifts, in the case of manual operation of moveable stops or automatic triggering device, the mechanical safety device according to 5.5.2.4.1 b) shall be operated by the safety system (5.5.3), in order to prevent any movement of the car in the up direction if the movable stops or the triggering device is not in the active position.