Separation can be achieved in several ways. Depending on a particular application and the requirements for maintenance, this may include: PVC sleeving, wrapping or plastic coating of conductors. Insulated terminal shields or PVC 'boots'. And these functions: Impede the passage of solid bodies between different parts of the switchboard (degree of. Each Form relates to the internal separation of the busbars, functional units and terminals, each being defined as: Internal separation is achieved by the use of barriers or partitions (including metallic or non-metallic), insulation of live parts or an integral housing (i. moulded case circuit. Yet, the terminology around forms of segregation —like Form 3B or Form 4aih—can seem overwhelming. This clause concerns methods of separating busbars and 'functional units' from one another when installing electrical control systems.
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