What does 133 represent in relay protection
In and, ANSI Device Numbers can be used to identify equipment and devices in a system such as,, or. Many of these devices protect electrical systems and individual system components from damage whe. Device number 1 3 4 Time-delay starting or closing relay is a device that functions to give a desired amount of time delay before or after any point of operation in a switching sequence or protective relay system, except as specifically provided by device functions 48, 62 and 79. The protection and control devices in electrical equipment can be referred to by numbers, with appropriate suffix letters when necessary, according to the functions they perform. Cables in this category may be applied where the power system's protective relaying apparatus can clear a ground fault (an unintentional connection to ground of one or more current-carrying conductors) in less than 1 minute.
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