Force Contact Inputs - GE L90 Instruction Manual

5 SETTINGS
Table 5–26: TEST MODE OPERATION
TEST MODE TEST MODE
FUNCTION FORCING
OPERAND
Disabled No effect
Isolated No effect
Forcible On (logic 1)
Off (logic 0)
The setting can only be changed by a direct user command. Following a restart, power up, settings
TEST MODE FUNCTION
upload, or firmware upgrade, the test mode will remain at the last programmed value. This allows a L90 that has been
placed in isolated mode to remain isolated during testing and maintenance activities. On restart, the
setting and the force contact input and force contact output settings all revert to their default states.
PATH: SETTINGS TESTING
FORCE CONTACT
INPUTS
MESSAGE
MESSAGE
The relay digital inputs (contact inputs) could be pre-programmed to respond to the test mode in the following ways:
• If set to "Disabled", the input remains fully operational. It is controlled by the voltage across its input terminals and can
be turned on and off by external circuitry. This value should be selected if a given input must be operational during the
test. This includes, for example, an input initiating the test, or being a part of a user pre-programmed test sequence.
• If set to "Open", the input is forced to report as opened (Logic 0) for the entire duration of the test mode regardless of
the voltage across the input terminals.
• If set to "Closed", the input is forced to report as closed (Logic 1) for the entire duration of the test mode regardless of
the voltage across the input terminals.
The force contact inputs feature provides a method of performing checks on the function of all contact inputs. Once
enabled, the relay is placed into test mode, allowing this feature to override the normal function of contact inputs. The Test
Mode LED will be on, indicating that the relay is in test mode. The state of each contact input may be programmed as "Dis-
abled", "Open", or "Closed". All contact input operations return to normal when all settings for this feature are disabled.
GE Multilin
IN-SERVICE TEST MODE
LED LED
Unaffected Off
Off On
Off Flashing
Off Flashing

FORCE CONTACT INPUTS

FORCE Cont Ip 1
:Disabled
FORCE Cont Ip 2
:Disabled
↓
FORCE Cont Ip xx
:Disabled
L90 Line Current Differential System
CRITICAL INPUT AND OUTPUT BEHAVIOR
FAIL
RELAY
Unaffected Contact outputs and inputs are under normal
operation. Channel tests and PMU tests not
operational (where applicable).
De- Contact outputs are disabled and contact inputs
energized are operational. Channel tests and PMU tests
are also operational (where applicable).
De- Contact inputs and outputs are controlled by the
energized force contact input and force contact output
functions. Channel tests and PMU tests are
operational (where applicable).
De- Contact outputs and inputs are under normal
energized operation. Channel tests and PMU tests are also
operational (where applicable).
5.10.2 FORCE CONTACT INPUTS
Range: Disabled, Open, Closed
Range: Disabled, Open, Closed
Range: Disabled, Open, Closed
5.10 TESTING
TEST MODE FORCING
5
5-281