CEI EN 50557 PDF

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;

– ARD that reclose without any assessment.

NOTE 1 The assessment cannot substitute the verifications required by HD 60364-6:2007.

NOTE 2 The requirements and tests for the assessment function in IT systems are under consideration.

This European Standard does not apply to ARDs with multiple settings adjustable by means accessible to the user in normal service.

This European Standard states:

– the terms and definitions used for ARD (Clause 3);

– the classification of ARD (Clause 4);

– the characteristics of ARD (Clause 5);

– the preferred values of the operating and influencing quantities (Clause 5);

– the marking and information to be provided for ARD (Clause 6);

– the standard conditions for installation and operation in service (Clause 7);

– the requirements for construction and operation (Clause 8);

– the list of minimum requirements to be tested (Clause 9).