ISO 12499 pdf download.Industrial fans — Mechanical safety of fans — Guarding
1 Scope
This International Standard specifies requirements for the mechanical guarding of industrial fans. The circumstances under which safety measures shall be taken are described and information on how hazards can be reduced or eliminated is given, along with guidance on safety practices and information for use.
2 Normative references
The following standards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO 3864:1 984 1 ) , Safety colours and safety signs. ISO 1 3349: — 2) , Industrial fans — Vocabulary and definitions of categories . ISO 1 3852:1 996, Safety of machinery — Safety distances to prevent danger zones being reached by the upper limbs. ISO 1 41 20: — 2) , Safety of machinery — General requirements for the design and construction of guards (fixed, movable).
3 Definitions
For the purposes of this International Standard, the definitions given in ISO 1 3349 and the following definitions apply. 3.1 industrial fan any fan used for industrial purposes, including the ventilation of buildings and mines but excluding ceiling, pedestal and similar circulation type fans such as those commonly used for non- industrial purposes 3.2 normal operation operation when the fan impeller is rotating and the fan is fulfilling its designed function of moving air 3.3 ancillary operation operation when the fan impeller is stationary and all power to the fan has been disconnected to allow such activities as maintenance, cleaning, adjustment or troubleshooting to take place 3.4 windmilling rotation of a fan impeller induced by flow across the impeller 3.5 hazard source of possible injury or damage to health 3.6 hazardous situation any situation in which a person is exposed to a hazard or to hazards 3.7 personal injury hurt caused to or sustained by a person as a result of mechanical hazard 3.8 risk combination of the probability and the degree of the possible injury or damage to health in a hazardous situation 3.9 danger zone danger point any zone or point at or near the fan where a person is exposed to risk of injury or damage to health 3.10 guard guarding mechanical means whereby mechanical hazards associated with industrial fans are minimized or avoided 3.10.1 fixed guard guard kept in place by means of fasteners, making removal impossible without using tools 3.10.2 fixed distance guard fixed guard which does not completely enclose a danger zone, but which prevents or reduces access by virtue of its physical dimensions and its distance from the hazard 3.11 safeguarding safety measures consisting of the use of specific technical means called safeguards (guards, safety devices) to protect persons from hazards which cannot reasonably be removed or sufficiently limited by design 3.12 residual risk risk remaining after specified safety measures have been taken during design or by the application of safeguarding 3.13 safe working practice system of working which reduces or eliminates the risk of injury 3.14 information for use safety measures consisting of communication links, such as text, words, signs, signals, symbols or diagrams, used separately or in combination, to convey information to the user NOTE Information for use is directed to professional and/or nonprofessional users.
4 Hazards from fans
A person may be injured by a fan as a result of: a) being trapped between a moving and stationary part, e.g. a fan impeller and casing or other fixed part of a fan; b) being trapped between two moving parts, e.g. a belt and pulley; c) being drawn into the fan inlet by air movement, resulting in contact with a rotating shaft or impeller; d) coming into contact with a moving part, such as an impeller; e) object being drawn into the fan inlet and ejected at high velocity at fan discharge or inlet; f) structural failure of fan components; g) contact with surfaces of the fan at extreme temperatures (i.e. less than 220 °C or greater than + 50 °C); h) noise emission caused by safeguards; i) even when a fan is switched off, the rotating parts can still be caused to windmill by air driven through the fan, either naturally or by fan(s) in other parts of the duct system connected to the fan; this could cause injury as the result of contact with a moving part, such as an impeller; j) unauthorized opening of access doors provided in the fan or connecting ductwork, if done whilst the fan is operating, can cause injury as the result of being drawn into the fan inlet by air movement, resulting in contact with a rotating shaft or impeller, or contact with a moving part, such as an impeller. NOTE Figure 2 illustrates typical mechanical hazards referred to in a) to d).