What is LSC (loss of service continuity category)

LSC stands for: Loss of Service Continuity category

The IEC 62271-200 proposes user-oriented definitions and classifications intended to describe how a given switchgear can be accessed, and what will be the consequences on the installation.#

When the accessibility of the various compartments are known, then the consequences of opening a compartment on the operation of the installation can be assessed; it is the idea of Loss of Service Continuity which leads to the LSC classification proposed by the IEC: “category defining the possibility to keep other high-voltage compartments and/or functional units energised when opening a accessible high-voltage compartment”.

Several categories are defined, according to “the extent to which the switchgear and controlgear are intended to remain operational in case access to a high-voltage compartment is provided”:

• LSC1: If any other functional unit than the one under intervention has to be switched off, then service is partial only:
• LSC2 If at least one set of busbars can remain live, and all other functional units can stay in service, then service is optimal:
• LSC2A or LSC2B: If within a single functional unit, other(s) compartment(s) than the connection compartment is accessible, then suffix A or B can be used with classification LSC2 to distinguish whether the cables shall be dead or not when accessing this other compartment.

If no accessible compartment is provided, then the LSC classification does not apply

For a more complete description please download the Medium Voltage technical guide.

Released for:Schneider Electric Ireland