Tag naming conventions for non-process equipment


Thread Starter

Tomas Fever

There are well defined ISA naming rules for process equipment (sensors, indicators, transmitters, etc.) and associated signals (output, input, alarms, etc.). There are other types of equipment that do not fit (as far as I know) in these definitions, such as motor protective relays, power meters and many others that generally match the definition of IED (Intelligent Electronic Device). I'm looking for any formal code or good practice used to name this type of equipment and associated signals.

Bruce Durdle

For protection relays, there is a well-defined numerical code used to indicate a function. From memory, 49 is an earth fault relay, 87 is used for differential protection, 52 is used for a circuit breaker. So a suitable code for an earth fault relay for motor M-654 could be M-654-49.

The power boys use numerical relay function identification for switchgear and motor controls. I think that the protection device numbers may comply with IEEE standards but I do not know the details. The device functions are less applicable now with the multi-functional relays (like Multilin).

Examples include the following:
12 Overspeed
24 Overexcitation, Volts/Hz
27 Undervoltage
27 Undervoltage
32 Power Direction - Reverse power for anti-motoring
38 Bearing overtemperature
39 Bearing vibration (analog inputs)
40 Loss of Excitation
40Q Loss of field
46 Current Unbalance - Negative Sequence Overcurrent
47 Voltage phase reversal
49 Stator thermal (RTD and thermal model)
49R Overload (RTD)
50/27 Inadvertent generator energization
50/51GN Instantaneous or definite time overcurrent
50BF Breaker failure detection
50GS Instantaneous Overcurrent
50S Instantaneous overcurrent (during startup)
51GN Time Overcurrent Ground
51V Time Overcurrent (V Restraint)
51V Voltage restrained phase overcurrent
59 Overvoltage
59GN/27TN 100% stator ground
60FL VT fuse failure detection
64B Bus Ground Detection
81 Over and underfrequency
81L/H Frequency
86G Lockout Auxiliary
87G Phase differential