Schneider Electric Class 615 dimensions IEC 947-2 Test Procedure

Compact® NSF and NSJ 150 to 600 A Circuit Breakers

Section 13—Supplementary Technical Information

IEC 947-2 TEST PROCEDURE

Standard Tests Consisting of seven parts, the IEC 947 Standard applies to all low-voltage equipment designed for industrial application.

Three documents are to be consulted for circuit breakers and switches:

•IEC 947-1: general regulations

•IEC 947-2: circuit breakers

•IEC 947-3: switches

Two Categories of Devices

Breaking Capacity

The IEC 947-1 standard defines two categories of devices:

•Category A—devices not specifically designed to carry out chronometric selectivity

•Category B—devices specifically designed to carry out chronometric selectivity; these circuit breakers possess a compulsory additional characteristic: short-time withstand (Icw)

Ultimate Breaking	Icu is the value to be taken into account when calculating an installation. The rule remains: Icu > Icc
Capacity: Icu	(maximum fault current of the installation).
Breaking	This characteristic indicates the ability of the device to eliminate short-circuit currents less than Icc and
Performance During	with a greater likelihood of occurring, generally near the application. Ics is expressed in % of Icu (values
Operation: Ics	retained by the standard IEC 25-50-75-100% of Icu). This test sequence designed to check the Ics
	performance, groups together on the same device, following the breaking test (O-CO-CO, see page
	72), certain checks such as:
	• Temperature rise under In
	• Calibration at 1.45 In
	• Leakage current (for devices suitable for disconnection)
	The leakage current should not exceed 2 mA under the application voltage (0.5 mA when new). These
	checks ensure that the device is able to carry out all its functions after elimination of a fault of Ics value
	and to be put back in operation; hence the notion of breaking power performance during operation Ics.

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