Switchgear surface

Painting of all metallic surfaces of a switchgear or a controlgear assembly is an essential requirement to provide it with an aesthetic appearance, on the one hand, and to prevent it from rust and corrosion, on the other. Painting serves these purposes by providing the machine with a hard and longer-lasting metallic surface. We describe briefly, the basic procedure to paint and test painted surfaces. In the discussion, we have laid more emphasis on MS sheet-metal surfaces as these are more typical. 

Switchgear and controlgear assemblies 13/403 Table A13.3 Pickling and de-rusting process in mildly scaled and mildly rusted surfaces... 

Various lEC standards for switchgear refer to IEC60694 sub-section 4.4.1 for the requirements of rated current and sub-section 4.4.2 for temperature rise of enclosed components such as bare terminals, busbars and risers, panel surfaces, and built-in apparatus. It also refers to IEC60085 for the classes of insulation. Busbars and risers can be bare or insulated and so it is not practical to state a requirement for their temperature rise in the project specification. 

In addition to their excellent dielectric properties, RPs provide necessary strength with reduced silhouette and weight. The corrosion resistant, smooth, hard surfaces also resist the embedment of contaminants. Since at least the 1940s utility companies have used components that include pole-top pins, adjustable tension braces, guy-strain insulators, line spacers, insulator pins, upsweeps, double-insulator standoff brackets, switch control rods, hot sticks, and switchgear components. 

Compliance entails having a competent person available on the surface in touch with those underground so that he can switch off the supply, on request, in the event of danger. The switchgear has to be located on the surface and may be manually or remotely controlled. It should be capable of safely interrupting both its rated load current and the potential fault current arising from a short circuit fault. 

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