ITU-T Work Programme

[2017-2020] : [SG5] : [Q2/5]

[Declared patent(s)]

Work item:

K.sod

Subject/title:

Surge and over-current protection parameters of external disconnector for surge protective devices used in telecommunication equipment

Status:

Discontinued [Issued from previous study period]

Approval process:

AAP

Type of work item:

Recommendation

Version:

New

Equivalent number:

Timing:

Liaison:

Supporting members:

China Unicom,China Telecom Corporation, Hua Wei

Summary:

Surge protective device (SPD) disconnectors are used to safely isolate degraded or failed SPDs from a low voltage power system. SPD disconnectors are classified as "internal" or "external" ones. Generally, the external disconnector is required to disconnect a large current derived from a sudden SPD failure. For a telecommunication equipment, the external disconnectors could be put in the SPD circuit or in line with the mains, which depends on coordination with overcurrent protective devices and on the balance of the need for continuity of power supply compared to continuity of protection. In order to acquire an appropriate coordination with the associated SPD and the upstream overcurrent protector, the surge and over-current protection parameters of the external disconnector need to be defined. This Recommendation sets terms, technical requirements and test methods for the surge and over-current protection parameters of external disconnector for the associated SPDs used in AC mains. This Recommendation also gives the guide on the application of the external disconnector.

Comment:

Reference(s):

[SG5-C470

]