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IEC 61557-11-2020 pdf download

IEC 61557-11-2020 pdf download.Electrical safety in low voltage distribution systems up to 1 000 V AC and 1 500 V DC – Equipment for testing, measuring or monitoring of protective measures – Part 11: Effectiveness of residual current monitors (RCM) in TT, TN and IT systems.
4.2.2 Non-operatIng test
When a test at 50 % or less of the rated residual operating current is used to test the reliability of the RCM is included, the minimum test period shall be 10 s. The alarm shall not be activated.
When a non-operating test at 50 % or less of the rated residual operating current is included. the operating uncertainty of the calibrated test current shall not exceed 0 % to —10 % of the specified non-operating test current.
NOTE Existing leakage currents downstream can influence the verification.
4.2.3 Test of actuating time
If the set actuating time of the RCM is being tested with the test equipment, the setting of the test period on the test device shall have a resolution of minimum 0,5 s ranging up to 10 s. The setting uncertainty shall not exceed 0 % to —10 % of the set value. The test shall solely be performed with calibrated AC test current.
Other methods for the acquisition of the actuating time via optical recognition or Interfacing are permissible.
NOTE The general function of RCMs is not to disconnect the power supply when a residual current above the value of the rated residual operating current occurs. The RCM Indicates the increase of the residual current above the residual operaling current with a signalling device, for example a lamp, buzzer, contact relay or interface-signal. Thus, the response time can only be tested via the visual or additional electrical detection of this signal.
According to IEC 62020-1, the actuating time of the RCM may only amount to a maximum of 10 s. The response time shall be specified by the manufacturer or shall be adjustable on the device.
If the RCM is being used for the purpose of disconnection, the tests covered by IEC 61 557-6 shall apply.
4.3 Fault voltages exceeding t’L
Prevention of danger due to fault voltages exceeding UL within the system under test shall be ensured during the use of the test equipment. This can be achieved as follows:
— automatic disconnection in accordance with IEC 61010-1:2010, Figure 1, if the residual voltage is above 50 V AC or 120 V DC;
— application of test current ‘T’ gradually or permanently adjustable, where the test starts with a maximum current of 3,5 mA AC or 15 mA DC in accordance with IEC 61010-1:2010, 6.3.2 b), including parallel test circuits, is permitted. The possibility to change the test current ‘T without generating a dangerous fault voltage shall be clearly identifiable, for instance on a voltmeter;
— in special locations, the touch voltage limit is 25 V AC or 60 V DC;
— the operating uncertainty for the detection of the fault voltage shall not exceed 0 % to —20 % of the limit.
4.4 Overvoltage
If the system is connected to 120 % of the nominal voltage of the system for which the test equipment is designed, neither the operator shall be harmed, nor the device be damaged. Protective devices shall not be activated. If the device is intended to be used in IT systems, the nominal voltage of the test equipment is the line-to-line voltage.IEC 61557-11 pdf download.

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