IEC/SC 77C - IEC_SC_77C

2012-03-14: Publication editing allocated to svandriessche@cencenelec.eu

Describes the immunity test levels and related test methods for electrical and electronic equipment and systems exposed to high-altitude electromagnetic pulse (HEMP) environments. Specifications for test equipment and instrumentation test set-up, test procedures, pass/fail criteria, and test documentation requirements are also defined by this standard. These tests are intended to demonstrate the immunity of electrical and electronic equipment when subjected to HEMP radiated and conducted electromagnetic disturbances. The objective of this part of EN 61000 is to establish a common and reproducible basis for evaluating the performance of electrical and electronic equipment, when subjected to HEMP radiated environments and the associated conducted transients on power, antenna, and input/output (I/O) signal and control lines.

Describes performance requirements, test methods and classification procedures for degrees of protection provided by empty enclosures against electromagnetic disturbances for frequencies between 10 kHz and 40 GHz. The shielding protection is measured for the purpose of demonstrating that the enclosure provides adequate shielding of electromagnetic energy to support acceptable performance of the complete assembled units when tested to applicable IEC standards. The purpose of this standard is to provide a repeatable means for evaluating the electromagnetic shielding performance of empty mechanical enclosures, including cabinets and subracks, and to specify a marking code to allow a manufacturer to select an enclosure with a known capability for attenuating electromagnetic fields. The requirements for immunity to various types of electromagnetic disturbances, including lightning and high-altitude electro-magnetic pulse (HEMP) will need to be considered by manufacturers when determining the need for application of this standard for specific equipment and applications, and for the specific enclosure shielding requirements which are necessary as a function of frequency.

This section of IEC 61000-2 defines the high-altitude electromagnetic pulse (HEMP) environment that is one of the consequences of a high-altitude nuclear explosion. Those dealing with this subject consider two cases: - high-altitude nuclear explosions; - low-altitude nuclear explosions. For civil systems, the most important case is the high-altitude nuclear explosion. In this case, the other effects of the nuclear explosion: blast, ground shock, thermal and nuclear ionizing radiation are not present at the ground level. However the electromagnetic pulse associated with the explosion may cause disruption of, and damage to, communication, electronic and electric power systems thereby upsetting the stability of modern society. The object of this standard is to establish a common reference for the HEMP environment in order to select realistic stresses to apply to victim equipment for evaluating their performance.

This part of 61000-5 defines how protective devices for conducted disturbance proposed for HEMP protection shall be specified. It is intended to be used for the harmonization of existing or future specifications issued by protective device manufacturers, electronic equipment manufacturers, administrations and other ultimate buyers. Performance requirements shall be given in future IEC documents. This section covers protective devices currently being used for protection against induced HEMP transients on signal and low voltage power lines (nominal voltage up to 1 kV a.c.). General information can be applied also to high voltage lines. However, in these cases, the additional requirements for the protection levels of existing lightning arresters (especially gapless MO-arresters) are under consideration.

Provides the basic reasons behind HEMP testing and gives a brief description of the most important concepts for shielding element testing. For each test, the following basic information is provided: - theoretical foundation of the test (the test concept); - test set-up; - required equipment; - test procedures; - data processing.

Defines the high-altitude electromagnetic pulse (HEMP) conducted environment that is one of the consequences of a high-altitude nuclear explosion. Establishes a common reference for this environment in order to select realistic stresses to apply to victim equipment for evaluating their performance. Presents the conducted HEMP environment induced on metallic lines, such as cables or power lines, external and internal to installations, and external antennas.

Deals with methods for testing protective devices for HEMP conducted disturbance. It primarily covers testing of voltage breakdown and voltage-limiting characteristics but also methods to measure the residual voltage under HEMP conditions for the case of very fast changes of voltage (u) and current (i) as a function of time.