GEK-113032A W650 Wind Generator Protection System 5-955 SETTINGS 5.6 INPUTS/OUTPUTS55.6.5 CIRCUIT SUPERVISION AND CONTACT SEAL-IN CIRCUITSCircuit Supervision:W650 elements can include supervision boards (type 2). This type of board includes 4 voltage detectors for implementingtripping or opening circuit supervision control logics.Contact Seal-in:The current seal-in circuit is used for verifying the current condition in a circuit during the time that the tripping contactremains closed. If the current in the tripping circuit is maintained over 200 mA, the function is sealed independently of thestatus of the function that caused the trip.This current seal-in function in tripping circuits is mainly used in applications where auxiliary contacts 52/a (in charge ofcutting the current in the tripping circuit) are very slow. This may cause that, once the function that produced the trip isreset, the relay contact will open before the breaker auxiliary 52/a, even if the time delay of the first has expired.By using this function, we prevent the relay contact from cutting the current (basically inductive and high) from the trippingcircuit, which could cause damage to the element, as these currents exceed the nominal breaking characteristics.The circuit and the current threshold of the function are as follows:Figure 5–25: CURRENT SUPERVISION5.6.5.1 DIGITAL INPUTSa) WITH TRIP CIRCUIT SUPERVISIONThe supervision board includes:8 digital inputs in two groups of 4 inputs with one common, in terminals F9 to F108 auxiliary outputs: 6 normally open contacts in terminals F19 to F30 and two current sensing (latching) outputs (F31-F33and F34-F36).2 groups of inputs for trip circuit supervision with 4 voltage detectors. The first group includes two isolated digital inputs,terminals F1-F2 and F3-F4. The second group, symmetrical and identical to the first, is formed by isolated voltage inputsF15-F16 and F17-F18.Using voltage detectors and current sensing, it is possible to implement several trip or close circuit supervision schemes, aswell as protection of the element output contact.100 mA min
