BS EN 81-77:2018 pdf free
BS EN 81-77:2018 pdf free.Safety rules for the construction and installations of lifts- Particular applications for passenger and goods passenger lifts Part 77: Lifts subject to seismic conditions.
5.4.3 Car door locking devices
To prevent the opening of car doors, for lifts in Seismic lift category 2 and 3, the car doors shall be provided with a car door locking device which shall he designed and operate as described in EN 8 1-20:2014, 5.3.9.2.
5.5 Counterweight or balancing weight
The counterweight or balancing weight shall be provided with upper and lower retaining devices able to hold the frame in between its guide rails.
The retaining devices shall be placed in such a way to distribute loads in a similar way as the guide shoes. The retaining devices shall either be integrated or mounted close to the fixing of the guide shoes.
The clearances d1, d2 and d3 (Figure 1 a)) between the retaining devices and the guide rails shall not exceed 5 mm. When a safety gear is present, the dimensions chosen for the clearances d1, d2 and d3 shall not cause accidental tripping of the safety gear.
During an earthquake, the minimum overlapping length (Z3) between retaining devices and the guide rail blade side shall be not less than 5 mm (Figure 1 b)).
The counterweight or balancing weight structure and retaining devices shall withstand the loads and forces imposed on them including forces generated by the design acceleration (ad), without permanent deformation.
The strength of the retaining devices and the counterweight frame or balancing weight frame shall be calculated taking into account the vertical mass distribution of the assembly of the counterweight frame or balancing weight including filler weights.
lithe counterweight or the balancing weight incorporates filler weights, necessary measures shall be taken to prevent their movement outside the frame considering the design acceleration value.
5.6 Suspension and compensation
5.6.1 Protection for traction sheaves, pulleys and sprockets
The devices for preventing the ropes from leaving the grooves of traction sheaves and pulleys shall include one retainer within 15° of the points where the ropes enter and leave the pulleys and at least one intermediate retainer every 900 of the angle of wrap. The strength and stiffness of the retainers and their distance to the traction sheaves and pulleys compared to the diameter of the ropes shall be such that they are effective.
The devices for preventing the chains from leaving the sprockets shall include one retainer within 15° of the points where the chains enter and leave the sprockets.
5.6.2 Compensation means
Compensation means provided according to EN 81-20:2014, 5.5.6 shall be guided in the pit in order to limit them from swaying and reaching snag points.
5.7 Precaution against environmental damage
Hydraulic lifts shall be provided with a rupture valve. The rupture valve shall comply with the
requirements of EN 81-20:2014, 5.6.3.
5.8 Guide rail system
5.8.1 General
The guide rails, their joints and attachments shall comply with the requirements of EN 81-20:20 14, 5.7 and they shall also withstand the loads and forces generated by the design acceleration (ad).
Where retaining devices are provided, car and counterweight or balancing weight retaining devices shall be used as frame supporting points in the guide rail verification.
NOTE Annex I) describes an example method for selecting guide rails.
5.8.2 Permissible stresses and deflections during seismic event
5.8.2.1 Where retaining devices are not provided, the maximum permissible deflections of the car guide rail system shall comply with the requirements of EN 81-20:20 14, 5.7, taking into account the load
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