Glossary
trip to occur. If the underfrequency condition subsides in less time than the delay time, the pickup will go inactive and the underfrequency function will reset. When tripping occurs, the actual condition that caused the trip is recorded in the device's nonvolatile trip log. Pickup occurs when the fre- quency in greater than the pickup setting.
Undervoltage (27) Relay function that protects against a
value supervision The ability of the ISGS relay to monitor its own input and measurement functions for problems.
Voltage Balance Relay function that protects against an unbalance in the phase voltages. The function monitors the phase voltages for approximate balance (of equal magni- tude). Balance is defined as the ratio of minimum to maxi- mum voltage, where the maximum voltage is the largest and the minimum voltage the smallest of the three phase volt- ages. The voltage is considered balanced and will not cause an alarm if the voltage min/max ratio is larger than the volt- age balance factor. The voltage balance factor indicates the amount of unbalance tolerated before the function generates an alarm. The function monitors for balance when the maxi- mum voltage is larger than the voltage balance pickup value. An alarm occurs when the min/max ration is smaller than the voltage balance factor.
VT Configuration A function to set up an ISGS relay with voltage input option to match VT primary rating and VT con- nection settings of an electrical distribution system.
Warning Indicates a potentially hazardous situation which, if not avoided, could result in death or serious injury.
G
Siemens Energy & Automation, Inc. |
