Last edit: 27/06/2023
Chapter 4 of the Standard provides general requirements concerning the electrical equipment of machines. In particular, the Standard describes the hazardous situations which could occur and moreover it identifies their causes, such as:
– Failures or faults in the electrical equipment resulting in the possibility of electrical shock, arc, or fire;
– Failures or faults in control circuits resulting in the malfunctioning of the machine;
– Disturbances or disruptions in power sources as well as failures or faults in the power circuits resulting in the malfunctioning of the machine;
– Loss of continuity of circuits that can result in a failure of a safety function, for example those that depend on sliding or rolling contacts;
– Electrical disturbances for example, electromagnetic, electrostatic either from outside the electrical equipment or internally generated, resulting in the malfunctioning of the machine;
– Release of stored energy resulting in electric shock, unexpected movement that can cause injury;
– Acoustic noise and mechanical vibration at levels that cause health problems to persons;
– Surface temperatures that can cause injury.
The Standard specifies that the Manufacturer, during both the design and development stage, shall identify hazards and the risks arising from them. Where the hazards cannot be removed and/or the risks cannot be sufficiently reduced by inherently safe design measures, protective measures shall be provided to reduce the risk. Additional means shall be provided where further risk reduction is necessary.
The Standard specifies, based on the kind of supply (alternate or continuous current) the parameters which the electrical equipment shall satisfy in order to work correctly.
In case of alternate current supply, the Standard specifies the following characteristics:
– Voltage unbalance;
– Voltage interruption;
– Voltage dips.
In case of direct current supply, based on the surgent, the Standard specifies the following characteristics:
- From batteries:
– Voltage interruption.
- From converting equipment:
– Voltage interruption.
The Standard specifies that the electrical equipment shall be suitable for the physical environment and operating conditions of its intended use. When special conditions apply or the limits specified are exceeded, an exchange of information between user and supplier can be necessary.
According to the physical environment, the Standard analyses the following parameters:
– Electromagnetic compatibility (EMC): the electrical equipment shall not generate electromagnetic disturbances above levels that are appropriate for its intended operating environment. In addition, the electrical equipment shall have a sufficient level of immunity to electromagnetic disturbances so that it can function in its intended environment.
– Ambient air temperature: the minimum requirement for all electrical equipment is correct operation in ambient air temperatures outside of enclosures between +5 °C and + 40 °C.
– Humidity: the electrical equipment shall be capable of operating correctly when the relative humidity does not exceed 50% at a maximum temperature of +40 °C.
– Altitude: electrical equipment shall be capable of operating correctly at altitudes up to 1000 m above mean sea level.
– Contaminants: electrical equipment shall be adequately protected against the ingress of solids and liquids.
– Ionizing and non-ionizing radiation: when equipment is subject to radiation, additional measures shall be taken to avoid malfunctioning of the equipment and accelerated deterioration of the insulation.
– Vibration, shock, and bump: the manufacturer shall avoid undesirable effects of vibration, shock and bump.
– Transportation and storage: electrical equipment shall be designed to withstand the effects of transportation and storage temperatures within a range of -25 °C to +n 55 °C and for short periods not exceeding 24 h at up to +70 °C.
– Provision for handling: heavy and bulky electrical equipment that has to be removed from the machine for transport, or that is independent of the machine, shall be provided with suitable means for handling.