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Work item:
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K.sod
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Subject/title:
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Surge and over-current protection parameters of external disconnector for surge protective devices used in telecommunication equipment
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Status:
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[Carried to next study period]
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Approval process:
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AAP
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Type of work item:
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Recommendation
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Version:
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New
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Equivalent number:
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-
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Timing:
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-
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Liaison:
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-
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Supporting members:
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China Unicom, China Telecom Corporation, Huawei
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Summary:
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With the develop trends of the miniaturization and integration of terminal telecommunication installations, such as integrated base stations, more cases or equipment have been integrated with CLASS ?or CLASS ? power SPDs.
In order to avoid the fire hazard under short-circuit failure mode for these SPDs, Moulded Case Circuit Breaker (MCB) or fuse, acted as the normal back-up over-current protective component (over-current disconnector ), has been widely used. But the normal MCB or fuse aims for over-current protection on power lines and the requirements under the installation scenario of coordination with SPDs are not considered. As a result, many problems are revealed, such as false operation under surge current, failure operation under little current or hysteretic operation under moderate or large current, high residual voltage under surge current.
In order to solve these problems, the external disconnector should have some specific performances under surge and over-current circumstances to achieve appropriate coordination with SPD. This Recommendation intends to provide the rating and measurement for the surge and over-current protection parameters of external disconnector for surge protective devices used in telecommunication equipment to instruct the relative selection and application.
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Comment:
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-
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Reference(s):
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Historic references:
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Contact(s):
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| ITU-T A.5 justification(s): |
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First registration in the WP:
2016-10-17 21:41:22
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Last update:
2016-11-07 09:56:01
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