IEEE C37 2-2008 pdf free download – IEEE Standard for Electrical Power System Device Function Numbers, Acronyms, and Contact Designations.
3.2.16 SER—sequence of events recorder A device / function that records events (changes of state of equipment or functions) with a time reference (commonly from a GPS or IRIG-B receiver).
3.2.17 TCM—trip circuit monitor A device / function that monitors an associated circuit breaker’s trip circuit for continuity and for the presence of tripping voltage, and sets an externally readable alarm when continuity or tripping voltage is lost (a surrogate for the traditional red light on relay and control panels).
3.3 Addition of prefixes and suffixes Letters and numbers may be used as prefixes or suffixes to the device function numbers in 3.1 to provide a more specific definition of the function, as discussed below. They permit a manifold multiplication of available function designations for the large number and variety of devices used in the many types of equipment covered by this standard. They may also serve to denote individual or specific parts or auxiliary contacts of these devices or certain distinguishing features, characteristics, or conditions that describe the use of the device or its contacts in the equipment. Prefixes and suffixes should, however, be used only when they accomplish a useful purpose.
For example, when all of the devices in a piece of equipment are associated with only one kind of apparatus, such as a feeder, motor, or generator, it is common practice, in order to retain maximum simplicity in device function identification, not to add the respective suffix letters F, M, or G to any of the device function numbers. In order to prevent any possible conflict or confusion, each letter suffix should preferably have only one meaning in individual pieces of equipment.
To accomplish this, short, distinctive abbreviations or any appropriate combination of letters may also be used as letter suffixes where necessary. However, each suffix should not consist of more than three (and preferably not more than two) letters, in order to keep the complete function designation as short and simple as possible. The meaning of each suffix should be designated on the drawings or in the publications with which they are used, similar to TC-trip coil, V-voltage, or X-auxiliary relay.
In cases where the same suffix (consisting of one letter or a combination of letters) has different meanings in the same equipment depending upon the device function number with which it is used, then the complete device function number with its suffix letter or letters and its corresponding function definition should be listed in the legend in each case, i.e., 63V-vacuum relay, 70R-raising relay for device 70, 90V-voltage regulator.
3.4 Suggested prefixes A similar series of numbers, prefixed by the letters RE (for remote) may be used for the interposing relays performing functions that are controlled directly from the supervisory system. Typical examples of such functions are RE1, RE5, and RE94. In multiple-unit installations, it may be desirable to use a prefix number to distinguish between device functions associated with individual units. For example, in pipeline pump stations, the numbers 1–99 are applied to device functions that are associated with the overall station operation. A similar series of numbers, starting with 101 instead of 1, are used for those device functions that are associated with unit 1; a similar series starting with 201 for device functions that are associated with unit 2; and so on, for each unit in these installations. Some utilities use the 100 series for devices / functions connected to the primary side of a substation, and the 200 series for the secondary side—e.g., a circuit breaker on a primary bus is a 152 device, and a circuit breaker on a secondary bus is a 252 device. 3.5 Suggested suffix letters Subclauses 3.5.1, 3.5.2, 3.5.3, 3.5.4, 3.5.5, and 3.5.6 describe letters that are commonly used and are recommended for use when required and as appropriate. In addition, there is a unique set of suffix letters applicable only to device number 16. See 3.1.16 and Annex D.IEEE C37 2 pdf download.