LV3.6.6 - 3.6.6 LV AC Power Circuit Protective Devices WG

Ronald Hotchkiss

The scope of this amendment is to define the application considerations for SPD Disconnectors and the coordination of these devices in Low Voltage AC Power Circuits. Application consideration details, potential issues and recommendations are provided.

" This standard establishes methods for testing and measuring the performance charac-teristics for surge-protective devices used in low-voltage ac power circuits. Definitions are statedthat apply specifically to surge-protective devices. The testing requirements are categorized intotwo groups, in which a minimum set of basic tests (BTs) are prescribed for all surge-protectivedevices within the scope of its documents, supplemented by additional tests (ATs) that might beneeded to establish particular application requirements. "

Information is provided to specifiers and users of surge-protective devices (SPDs) about the application considerations of SPDs associated with power distribution systems within North America. This guide applies to SPDs to be connected to the load side of the service entrance main over current protective device of 50 Hz or 60 Hz ac power circuits rated at 100?1000 V rms. The effects and side effects on the presence and operation of SPDs in low-voltage power distribution systems are described. The coordination of multiple SPDs on the same circuit is described.

Surge-protective devices (SPDs) intended to be installed on the load side of the service equipment connected to 50 Hz or 60 Hz AC power circuits rated at 1000 V (root mean squared [rms]) or less are the focus of this standard. Performance characteristics and standard methods for testing and rating are established for these devices, which may be composed of any combination of components. The tests in this standard are aimed at providing comparisons among the variety of SPDs available.

Guidance is provided to specifiers, users and manufacturers of surge-protective devices (SPDs) about the application considerations of SPDs to power distribution systems and associated equipment. This guide applies to SPDs to be connected to the load side of the service equipment (and main over current protective device) of 50 Hz or 60 Hz ac power circuits rated 1000 V ac or less. Information on surge origins, effects of surges, number and magnitude of surge events, location categories, power distribution system (PDS) configurations, grounding and bonding, SPD specifications, SPD ratings, SPD characteristics, SPD lifetime, interactions of SPDs with a PDS, and SPD coordination considerations are provided in the guide.