GE N60 Instruction Manual page 345

CHAPTER 5: SETTINGS
For example, the trip circuit current is monitored by providing a current threshold detector in series with some Form-A
contacts (see the trip circuit example in the Digital Elements section). The monitor sets a flag (see the specifications for
Form-A). The name of the FlexLogic operand set by the monitor, consists of the output relay designation, followed by the
name of the flag; for example,
In most breaker control circuits, the trip coil is connected in series with a breaker auxiliary contact used to interrupt current
flow after the breaker has tripped, to prevent damage to the less robust initiating contact. This can be done by monitoring
an auxiliary contact on the breaker which opens when the breaker has tripped, but this scheme is subject to incorrect
operation caused by differences in timing between breaker auxiliary contact change-of-state and interruption of current in
the trip circuit. The most dependable protection of the initiating contact is provided by directly measuring current in the
tripping circuit, and using this parameter to control resetting of the initiating relay. This scheme is often called trip seal-in.
This can be realized in the N60 using the
: "Cont Op
CONTACT OUTPUT H1 ID
: any suitable FlexLogic operand
OUTPUT H1 OPERATE
: "Cont Op 1
OUTPUT H1 SEAL-IN
CONTACT OUTPUT H1 EVENTS
5.9.3.2 Latching outputs
SETTINGS  INPUTS/OUTPUTS  CONTACT OUTPUTS  CONTACT OUTPUT H1a
 CONTACT OUTPUT H1a

The N60 latching output contacts are mechanically bi-stable and controlled by two separate (open and close) coils. As such
they retain their position even if the relay is not powered up. The relay recognizes all latching output contact cards and
populates the setting menu accordingly. On power up, the relay reads positions of the latching contacts from the hardware
before executing any other functions of the relay (such as protection and control features or FlexLogic).
The latching output modules, either as a part of the relay or as individual modules, are shipped from the factory with all
latching contacts opened. It is highly recommended to double-check the programming and positions of the latching
contacts when replacing a module.
Since the relay asserts the output contact and reads back its position, it is possible to incorporate self-monitoring
capabilities for the latching outputs. If any latching outputs exhibits a discrepancy, the LATCHING OUTPUT ERROR self-test
error is declared. The error is signaled by the
— This setting specifies a FlexLogic operand to operate the 'close coil' of the contact. The relay seals-
OUTPUT H1a OPERATE
in this input to safely close the contact. Once the contact is closed and the
input, such as subsequent chattering, does not have any effect. With both the
OPERATE
(logic 1), the response of the latching contact is specified by the
— This setting specifies a FlexLogic operand to operate the 'trip coil' of the contact. The relay seals-in
OUTPUT H1a RESET
this input to safely open the contact. Once the contact is opened and the
input, such as subsequent chattering, does not have any effect. With both the
RESET
1), the response of the latching contact is specified by the
— This setting specifies the contact response under conflicting control inputs; that is, when both the
OUTPUT H1a TYPE
and signals are applied. With both control inputs applied simultaneously, the contact closes if set to
OPERATE RESET
"Operate-dominant" and opens if set to "Reset-dominant."
N60 NETWORK STABILITY AND SYNCHROPHASOR MEASUREMENT SYSTEM – INSTRUCTION MANUAL
.
Cont OP 1 IOn
FlexLogic operand to seal-in the contact output as follows:
Cont OP 1 IOn
1"
IOn"
: "Enabled"
OUTPUT H1a ID

L-Cont Op 1
OUTPUT H1a OPERATE:

Off
OUTPUT H1a RESET:

Off
OUTPUT H1a TYPE:

Operate-dominant
OUTPUT H1a EVENTS:

Disabled
LATCHING OUT ERROR
OUTPUT H1a TYPE
Range: up to 12 alphanumeric characters
Range: FlexLogic operand
Range: FlexLogic operand
Range: Operate-dominant, Reset-dominant
Range: Disabled, Enabled
FlexLogic operand, event, and target message.
input is logic 0 (off), any activity of the
RESET
OPERATE
setting.
OUTPUT H1a TYPE
input is logic 0 (off), any activity of the
OPERATE
OPERATE
setting.
INPUTS/OUTPUTS
and inputs active
RESET
and inputs active (logic
RESET
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