BS EN 50557:2011 PDF

1   Scope This European Standard applies to Automatic Reclosing Devices (hereinafter referred to as “ ARD ”) for household and similar uses, for rated voltage not exceeding 440 V a.c. intended to be used in combination with circuit-breakers and/or RCCBs and/or RCBOs, and designed either for factory assembly or for assembly on site. These devices are intended to reclose main protective devices (hereinafter referred to as “ MPD ”) such as circuit-breakers complying to EN 60898‑1 and/or EN 60898‑2, RCCBs complying to EN 61008‑1 and RCBOs complying to EN 61009‑1 after tripping of those devices in order to re-establish continuity of service. In detail, this European Standard applies to the following types of ARD :

– ARD with assessment means, reclosing only if both the prospective line current and the prospective earth-fault current do not exceed given values;

– ARD with assessment means, reclosing only if the prospective line current does not exceed a given value;

– ARD with assessment means, reclosing only if the prospective earth-fault current does not exceed a given value;