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A High Resistance Connection (HRC) is a problem that results from loose or poor connections in traditional electrical accessories and switchgear which can cause heat to develop, capable of starting a fire.〔(【引用サイトリンク】url=http://www.pgmdi.com/FEUpdateSummer2000.pdf )〕 Safety devices such as fuses and Residual-current devices (RCDs) are unable to detect thermal rise and disconnect the electrical supply because they cannot sense HRC. A safety device 〔(【引用サイトリンク】url=http://me2.ipo.gov.uk/p-find-publication-getPDF.pdf?PatentNo=GB2471869&DocType=B&JournalNumber=6414 )〕 〔(【引用サイトリンク】website=http://thermarestor.co.uk )〕 to prevent HRC operates by effectively monitoring for abnormal thermal rise and will prevent ignition, smoke or burning odour of the electrical accessory or electrical installation. An example extract from the National Union of Teachers (NUT) Fire Safety Brief ; : * Electrical equipment should be regularly maintained by competent people. Machines should not be allowed to overheat. Care should be taken not to cover machines while they are switched on as this is particularly likely to cause overheating. Trailing cables should be regularly checked for damage. Loose or poor connections in traditional electrical accessories and switchgear can cause heat to develop capable of starting a fire. This problem is known as High Resistance Connection (HRC) and safety devices such as fuses and Residual Circuit Devices (RCDs) are unable to disconnect the electrical supply because they cannot sense HRC. Consideration should be given to the installation of a preventative system designed to stop electrical connections and accessories from reaching a temperature which would result in a fire. Such a device operates by effectively closing a switch at a pre-set temperature to prevent ignition, smoke or burning odour. Thermal monitoring of the connection and providing a HRC Device close to the probable location where a fault may develop is key to providing early warning or isolation to reduce the risk of fire. == See also == *Residual-current device *Fuse (electrical) *National Union of Teachers 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「High Resistance Connection」の詳細全文を読む スポンサード リンク
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