BS EN 60204-33:2011 pdf free.Safety of machinery —Electrical equipment ofmachines Requirements for semiconductor fabrication equipment.
BS EN 60204-33 The risks associated with the hazards relevant to the electrical equipment shall be assessed aspart of the overall requirements for risk assessment of the fabrication equipment.This willenable the determination of adequate risk reduction，and the necessary protective measuresfor persons who can be exposed to those hazards,while still maintaining an acceptable level ofperformance of the fabrication equipment.
Hazardous situations can result from, but are not limited to, the following causes:
failures or faults in the electrical equipment resulting in the possibility of electric shockor electrical fire;
failures or faults in control circuits (or components and devices associated with thosecircuits) resulting in the malfunctioning of the fabrication equipment that can increaserisk;
disturbances or disruptions in power sources as well as failures or faults in the electricalequipment resulting in the malfunctioning of the fabrication equipment that can increaserisk;
loss of continuity of circuits that depend upon sliding or rolling contacts，resulting in afailure of a safety function;
electrical disturbances (for example electromagnetic，electrostatic either from outsidethe electrical equipment or internally generated，resulting in the malfunctioning of thefabrication equipment that can increase risk);
release of stored energy (either electrical or mechanical) resulting in，for example,electric shock,unexpected movement that can cause injury;
Safety measures are a combination of the measures incorporated at the design stage andthose measures required to be implemented by the user.
During the design and development process,hazards and the risks arising from them shall beidentified. Where the hazards cannot be removed and/or the risks cannot be sufficientlyreduced by inherently safe design measures, protective measures (for example safeguarding,)shall be provided to reduce the risk.Additional means (for example, awareness means) shallbe provided where further risk reduction is necessary. In addition，working procedures thatreduce risk can be necessary.
Electrical equipment shall be adequately protected against the ingress of solid bodies andliquids likely to be present in the environment in which the electrical equipment is intended tobe used. Electrical equipment shall be adequately protected against or resistant to degradationresulting from foreseeable chemical exposures.
When electrical equipment can be subject to radiation (e.g. microwave,ultraviolet, lasers，X-rays), additional measures shall be taken to avoid failures of the electrical equipment that canresult in a hazardous situation.BS EN 60204-33 pdf download.