EN 81-40-2008 pdf download.Safety rules for the construction and installation of lifts- Special lifts for the transport of persons and goods – Part 40: Stairlifts and inclined lifting platforms intended for persons with impaired mobility.
5.4 Driving units and drive system
5.4.1 General requirements
5.4.1.1 The selected drive method shall be w accordance with one of the systems speofied In Clause 1.1 of the scope.
5.4.1.2 All types of dnve shall be controlled In both dwectlons of travel such that uncontrolled movement of the stairtift is not possible.
5.4.1.3 The safety lactor used Ui the design of geared drive unit and any levelling drive shal be based on the static loads imposed by the rated load +25 % on the driving mechanism The safety factors used In the design of geared drive units shall be mair4ained, even after taking full account of the effects of wear and fatigue likely to arise during the designed life of the geared drive system.
NOTE Refer to ISO 9085.2002 for guidance concrmng the cakuletlon of load capaoty of spur and hehcal gears
Gearing slial be guarded as 1w as reasonably pscable, acconing to Clauses 4.24 1 and 42 4.2 of EN ISO
138572008
54.1.4 II chain or belt intermediate drives are empkyed within the drive system. then the following conditions shall be met:
a) Ui output drive gearing shall be on th load side of the chain or belt intermediate drive;
and either,
b) the output drive gearing shall be sell-sustaining, or
C) die brake shall be on the load side of the chains or belts intermediate drive and a mflmurn of 2 chains or belts shall be used. Chams or belts shall be independent. The chains or belts intermedIate drive shall be monitored by a slack chain or belt monitoring device that shall disconnect die supply to the motor and brake in die event of breakage of any chain or belt. lithe belts are used, die supply to the motor and brake shall also be disconnected In the event of the slackening of any belt
5.4.1.5 As an alternative to what Is stated In 5.4.1.4, a system with two chains intermediate drive may be used. The intermediate chains shall be monitored by an electric safety device that disconnects the supply to the motor and brake in the event of breakage of any chain
5.4.1.6 Ropes suspension or chains suspension systems shall incorporate a device that. in the event of a slack rope or chain, shall operate an electric safety device that shall initiate a break in the electrical supply to the motor and brake and thus prevent any movement of the carnage until the rope or chain is correctly re-tensioned.
5.4.1.7 For traction sheaves. pulleys and sp-ockets. provisions shall be made to avd:
a) boddyinury
b) ropes/chains leaving the pulleys/sprockets. if slack:
C) ntrodudbon of objects between ropes/chains and pulleys/sprockets.
The devices used shaM be constructed so that the rotating pails are visible, and do not hinder examination and maintenance operation. If they are perforated the gape shall comply wIth Table 4 of EN ISO 13857:2008. The dismantling shall be necessary only en the following cases:
d) replacement of a rope/chain:
e) replacement of a pulley/sprocket
Drums and pulleys shall be guarded so as to ensure that the rope is retained in the grooving to ensure that trapping between rope and drum or pulley cannot occur. Ropes shal also be guarded if their position is such as to create a hazard.
5.4.2 BrakIng syst.m
5.4.2.1 General
An electro-mechanecal friction brake shall be fitted which shall be capable of bringing the stairtlft to rest within a distance of 20 mm and holding ii timely en position under maxinum working load. The brake shall be mechanically apphed and electrically held off The brake shall not be released an normal opecabon unless the etectncal supply is simultaneously applied to the stairtifi motor, Interruption of Vie electrical supply to the brake shall be controlled wi accordance with 5.5.3.
5.4.2.2 Electro-mechanical brake
The component on which the brake operates shall be positively coupled to the final &ivrng element. e.g rope drum. chainwheel. screw, nut. etc.. unless the final driving element is self-sustaining or the dflve system complies with 5.4.1.5. Brake hnings shall be of flame retardant. selfextinguishing material and shall not support combustion. The brake Imings shall be so secured that normal wear will not weaken their fastenings, The design of the brake shall take into accotat the intended use and frequency to which it will b. subjected (see 5.1 2).
Braking shall be effective without any additional delay other than that requ Wed for tee natural operating twning of the braking system, after openWig of the release circuit.EN 81-40-2008 pdf download