This part of 61238 applies to compression and mechanical connectors for power cables for rated voltages up to 30 kV (Um = 36 kV), e.g. buried cables or cables installed in buildings, having a) conductors complying with IEC 60228 and IEC 60228A with cross-sectional areas 10 mm² and greater for copper and 16 mm² and greater for aluminium. b) a maximum continuous conductor temperature not exceeding 90 °C. This standard is not applicable to connectors for overhead conductors, which are designed for special mechanical requirements, or to separable connectors with a sliding contact or multi-core connectors (i.e. ring connectors). Although it is not possible to define precisely the service conditions for all applications, two broad classes of connectors have been identified. Class A These are connectors intended for electricity distribution or industrial networks in which they can be subjected to short-circuits of relatively high intensity and duration. As a consequence class A connectors will be suitable for the majority of applications. Class B These are connectors for networks in which overloads or short-circuits are rapidly cleared by the installed protective devices, e.g. fast-acting fuses. Depending on the application, the connectors are subjected to the following tests: Class A The connectors are subjected to heat cycles and short-circuit tests. Class B The connectors are subjected to heat cycles only.