There are few things in our industry to compete with the destructive force of an arcing fault in the main or distribution busbars. Under IEC/TR 61641, all electrical assemblies must be able to withstand a short circuit current. Press stoppers are considered essential to comply with the standard as part of the design criteria for enclosures.
Rittal’s pressure stoppers provide all the necessary safeguards for Ri4Power enclosures, protecting people and equipment from the potentially violent consequences of this event.
When an arc between phases occurs not only is a huge amount of energy released but the spark created by the ignition can reach temperatures of more than 10,000 degrees Celsius. This heats and expands the air within an enclosure creating a rise in pressure which can exceed the enclosure’s design parameters, leading to catastrophic failure.
Not surprisingly, this destructive force, allied with the sudden, explosive release of hot gases and particles into the surrounding atmosphere can have serious consequences for the operating personnel working on or standing close to the assembly line. Furthermore, there are likely to be substantial equipment and production losses with associated lengthy repair time and costs, adding up to considerable economic losses.
Internal short circuits which can lead to arcs are typically the result of hot spots, tracking across insulation material, animals or vermin entering into the assembly, loose parts or human errors.
All electrical assemblies under IEC / TR 61641 must be designed to take all necessary steps to withstand a specified short circuit current that is liable to result in internal arc fault conditions.
Pressure stoppers for roof plates provide pressure relief during arc fault, and a pressure relief function is essential for compliance with health and safety regulations for arcing under IEC/TR 61641.
Rittal’s pressure stoppers convert the IP 55 roof plate for Ri4Power enclosures into a roof plate with pressure relief function. This modification only takes minutes and can be retro-fitted on site if necessary. Rittal’s pressure relief stoppers have been successfully used in low-voltage applications up to 690V 50kA.
Further information about Rittal’s pressure relief stoppers can be found at www.rittal.co.uk.