Circuit Supervision And Contact Seal-In Circuits - GE F650 Instruction Manual

5.6 INPUTS/OUTPUTS 5 SETTINGS

5.6.5 CIRCUIT SUPERVISION AND CONTACT SEAL-IN CIRCUITS

Circuit Supervision:
F650 elements can include supervision boards (type 2), either in their internal slot F, or in an additional CIO module
connected to the element via a CAN Bus (slots H and J). This type of board includes 4 voltage detectors for implementing
tripping 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 contact
remains closed. If the current in the tripping circuit is maintained over 500 mA, the function is sealed independently of the
status 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 of
cutting the current in the tripping circuit) are very slow. This may cause that, once the function that produced the trip is
reset, 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 tripping
circuit, 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:
500 mA min
5
Figure 5–35: CURRENT SUPERVISION
5.6.5.1 DIGITAL INPUTS
a) WITH TRIP CIRCUIT SUPERVISION
The supervision board includes:
8 digital inputs in two groups of 4 inputs with one common, in terminals F9 to F10
8 auxiliary outputs: 6 normally open contacts in terminals F19 to F30 and two current sensing (latching) outputs (F31-F33
and 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 inputs
F15-F16 and F17-F18.
Using voltage detectors and current sensing, it is possible to implement several trip or close circuit supervision schemes, as
well as protection of the element output contact.
5-124 F650 Digital Bay Controller GEK-106310AB